Methanogenesis and productivity modifying composition

Abstract

The invention relates to methods and compositions for modifying methanogenesis and productivity in ruminants. In particular, the methods comprise co-administering a methanogenesis inhibitor and a productivity modifier.

Description

METHANOGENESIS AND PRODUCTIVITY MODIFYING COMPOSITIONPRIORITY DOCUMENTS

[0001] The present application claims priority from Australian Provisional Patent Application No. 2024901030 titled “METHANOGENESIS AND PRODUCTIVITY MODIFYING COMPOSITION” and filed on 12 April 2024, the content of which is hereby incorporated by reference in its entirety.TECHNICAL FIELD

[0002] The present disclosure relates to methods and compositions for modifying methanogenesis and productivity in ruminants. In particular, the methods comprise co-administering a methanogenesis inhibitor and a productivity modifier.BACKGROUND

[0003] Climate change is an increasing problem creating long-term shifts in temperatures and weather patterns. Greenhouse gas emissions from anthropogenic sources have been the main driver of climate change over the last 200 years. These sources are mainly due to energy, industry, transport, buildings, agriculture and land use. Climate change is resulting in increases in global temperatures, as well as increases in the length and severity of droughts, fires, and storms.

[0004] One of the drivers of climate change are greenhouse gas emissions from agriculture. With the global population due to increase to 9 billion by 2050, agricultural production must increase and therefore greenhouse gas emissions will continue to rise. Greenhouse gas emissions from animal agriculture are estimated to represent 14.5 percent of all anthropogenic greenhouse gas emissions.

[0005] There is mounting pressure to reduce herd sizes in an attempt to reduce greenhouse gas emissions from animal agriculture. However, animal products contain protein, fats, vitamins and minerals in the least allergenic and most bioavailable forms for human consumption. As such, there is a need to increase productivity of animal agriculture while reducing greenhouse gas emissions.

[0006] Numerous methods are used that attempt to improve productivity, including optimising protein, energy (e.g. cereal grains, silage), roughage, minerals (e.g. Ca, Mg, S) and buffers (e.g. NaHCOs, bentonite). Recently, it was discovered that supplementing the diet of ruminant animals with the red seaweed species Asparagopsis taxiformis reduced methane emissions. Red seaweed is difficult to cultivate and wild populations are limited.

[0007] There is thus a need to provide improved methods for modifying methanogenesis and productivity in ruminants.SUMMARY

[0008] The present inventors have surprisingly found that co-administering a methanogenesis inhibitor and a productivity modifier provides a synergistic effect on reducing methane production and reducing the acetate-to-propionate ratio. Acetate and propionate are two of the main short chain fatty acids formed by the gut bacteria. Reducing the ruminal acetate-to-propionate ratio (A:P ratio) can improve the efficiency of dietary energy utilization, also known as feed conversion efficiency. The ratio of acetate to propionate is an indicator of feed conversion efficiency and hence an indicator of growth of the animal.

[0009] Thus, in an aspect, the present disclosure provides a method of reducing methane production and increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

[0010] In another aspect, the present disclosure provides a method for managing methane emissions and weight gain in ruminant animals, comprising: (a) administering to the ruminant animal an effective amount of a methanogenesis inhibitor comprising one or more halogenated carbon compound, wherein the administration of the methanogenesis inhibitor results in a reduction in the weight gain of the animal and a reduction in methane emissions from the animal; and (b) co-administering to the ruminant animal an effective amount of a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof , wherein the productivity modifier at least partially recovers the reduction in weight gain caused by the methanogenesis inhibitor, without substantially negating the reduction in methane emissions achieved by the methanogenesis inhibitor.

[0011] In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co- administered simultaneously to the ruminant. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are formulated together. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered within 30 minutes or within 20 minutes or within 10 minutes of the consumption of a meal. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered at least every 12, 18, 24, 30, 36, 40 or 48 hours.

[0012] In certain embodiments, the methanogenesis inhibitor comprises a plurality of halogenated carbon compounds. In certain embodiments, the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform,bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3,3-dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, l,l,3,3-tetrabromopropan-2-ol, tribromomethanol, 1,1,3,3-tetrabromoacetone, 1,3- dichloroacetone, 1 , 1 ,3,3-tetrabromopropan-2-one, 1 , 1 ,3,3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3- chloropropan-2-one, 1 , 1 ,3-tribromopropan-2-one, 1 , 1 ,3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3- en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3- iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1 ,3-dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 - chloropropan-2-one, l,3-dibromopropan-2-one, l,3-dichloropropan-2-one, l-bromo-1,3,3- trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 -bromo-3-chloropropan-2-one, 1 -chloro-3- iodopropan-2-one, 3-bromo-l,l-dichloropropan-2-one, 2,2,2-tribromoacetic acid (ethyl ester), 2,2- dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2,2-dibromoacetic acid (methyl ester), 2-bromo- 2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3- dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid (methyl ester), 3-bromo-2- iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2,2-dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes, a-snyderol, [3-snyderol, y-snyderol, halogenated fatty acids, 3-bromo-2-heptanoic acids and 3-bromo-2- nonanoic acids, halogenated oxylipins, chlorinated egregiachloride A, chlorinated egregiachloride B, chlorinated egregiachloride C, chlorinated eiseniachloride A, chlorinated eiseniachloride B, chlorinated eiseniachloride C, iodinated eiseniaiodide A, iodinated eiseniaiodide B, halogenated terpenoids (e.g., diterpenes and triterpenes), halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan-2-ones or halogenated phenols or a combination thereof. In certain embodiments, the methanogenesis inhibitor comprises bromoform.

[0013] In certain embodiments, the ionophore comprises a polyether ionophorous antibiotic. In particular embodiments, the ionophore comprises one or more of lasalocid A or monensin A or a combination thereof.

[0014] In certain embodiments, the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate or a combination thereof.

[0015] In certain embodiments, the co-administering comprises administering about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI) or about 40 to about 120mg per kg DMI of the methanogenesis inhibitor. In certain embodiments, the co-administering comprises administering about 5 to about 150mg per kg DMI or about 20 to about 40mg per kg DMI of the ionophore. In certainembodiments, the co-administering comprises administering about 0.2 to about 20mg per kg DMI or about 1 to about 4mg per kg DMI succinate / propionate pathway compound.

[0016] In certain embodiments, the co-administering provides a rumen concentration of the methanogenesis inhibitor of about 2 to about lOuM or about 4 to about 6uM. In certain embodiments, the co-administering provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM or about 300 to about 400mM. In certain embodiments, the co-administering provides a rumen concentration of the ionophore of about 0.2 to about 20uM or about 1 to about 3uM.

[0017] In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:100. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:50 to about 1:80. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 20: 1 to about 1:1. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 15:1 to about 2:1.

[0018] In certain embodiments, the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae. In certain embodiments, the ruminant is one or more of mousedeer, deer, moose, giraffe and okapi, pronghorn, musk deer, cattle, goats, sheep, llama, alpaca, bison, elk, reindeer, yak, camel or antelope.

[0019] In a fourth aspect, the present disclosure provides a composition for reducing methane production and increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

[0020] In certain embodiments, the methanogenesis inhibitor comprises one or more halogenated carbon compounds. In certain embodiments, the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform, bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3,3-dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, l,l,3,3-tetrabromopropan-2-ol, tribromomethanol, 1,1,3,3-tetrabromoacetone, 1,3- dichloroacetone, 1 , 1 ,3,3-tetrabromopropan-2-one, 1 , 1 ,3,3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3- chloropropan-2-one, 1 , 1 ,3-tribromopropan-2-one, 1 , 1 ,3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3- en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3-iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1 ,3-dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 - chloropropan-2-one, l,3-dibromopropan-2-one, l,3-dichloropropan-2-one, l-bromo-1,3,3- trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 -bromo-3-chloropropan-2-one, 1 -chloro-3- iodopropan-2-one, 3-bromo-l J-dichloropropan-2-one, 2,2,2-tribromoacetic acid (ethyl ester), 2,2- dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2,2-dibromoacetic acid (methyl ester), 2-bromo- 2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3- dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid (methyl ester), 3-bromo-2- iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2,2-dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes (such as a-snyderol, [3-snyderol, and y-snyderol), halogenated fatty acids (such as 3-bromo-2-heptanoic acids and 3-bromo-2-nonanoic acids), halogenated oxylipins (e.g., chlorinated egregiachlorides A, B and C, chlorinated eiseniachlorides A, B and C, and iodinated eiseniaiodides A, B), halogenated terpenoids (e.g., diterpenes and triterpenes), halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan-2-ones or halogenated phenols or a combination thereof. In certain embodiments, the methanogenesis inhibitor comprises bromoform.

[0021] In certain embodiments, the ionophore comprises a polyether ionophorous antibiotic. In certain embodiments, the ionophore comprises one or more of lasalocid A or monensin A or a combination thereof.

[0022] In certain embodiments, the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate or a combination thereof.

[0023] In certain embodiments, a dosage of the composition provides about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI) of the methanogenesis inhibitor or about 40 to about 120mg per kg DMI of the methanogenesis inhibitor. In certain embodiments, a dosage of the composition provides about 5 to about 150mg per kg DMI or about 20 to about 40mg per kg DMI of the ionophore. In certain embodiments, a dosage of the composition provides about 0.2 to about 20mg per kg DMI or about 1 to about 4mg per kg DMI of the succinate / propionate pathway compound.

[0024] In certain embodiments, a dosage of the composition provides a rumen concentration of the methanogenesis inhibitor of about 2 to about lOuM or about 4 to about 6uM. In certain embodiments, a dosage of the composition provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM or about 300 to about 400mM. In certain embodiments, a dosage of the composition provides a rumen concentration of the ionophore of about 0.2 to about 20uM or about 1 to about 3uM.

[0025] In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:100. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:50 to about 1:80. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 20: 1 to about 1:1. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 15:1 to about 2:1.

[0026] In certain embodiments, the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae. In certain embodiments, the ruminant is one or more of mousedeer, deer, moose, giraffe and okapi, pronghorn, musk deer, cattle, goats, sheep, llama, alpaca, bison, elk, reindeer, yak, camel or antelope.

[0027] In certain embodiments, the methanogenesis inhibitor and the productivity modifier in combination when administered to a ruminant synergistically increase productivity / feed conversion efficiency or decrease methane emissions in said ruminant as compared to an additive effect of administering to a ruminant the methanogenesis inhibitor or the productivity modifier individually.

[0028] In another aspect, the present disclosure provides an animal feed supplement, comprising a composition of the disclosure.

[0029] In another aspect, the present disclosure provides an animal feed, comprising a composition of the disclosure or the supplement of the disclosure.

[0030] In another aspect, the present disclosure provides a kit comprising first and second containers, wherein the first container contains a methanogenesis inhibitor comprising one or more halogenated carbon compound, as described herein, and the second container contains a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, as described herein; optionally packaged with instructions for the use of the kit in the methods of the disclosure.BRIEF DESCRIPTION OF DRAWINGS

[0031] Embodiments of the present disclosure will be discussed with reference to the accompanying drawings wherein:

[0032] Figure 1 shows methane reduction in in vitro rumen cultures treated with bromoform, monensin A, fumarate and combinations thereof. Unpaired t-tests were performed between additive and observedeffects, (p-value for additive vs observed for bromoform and monensin A is 0.02 and p-value for additive vs observed for bromoform and fumaric acid is 0.021).

[0033] Figure 2 shows the decrease in acetate to propionate ratio measured in in vitro rumen cultures after 1 day of incubation.

[0034] Figure 3 shows acetate to propionate ratios of passaged in vitro rumen cultures over 3 days. Unpaired t-test was performed between additive and observed bromoform and monensin A effects (p- value: 0.037).DESCRIPTION OF EMBODIMENTSDEFINITIONS

[0035] The following definitions are provided for specific terms which are used in the following written description.

[0036] As used in the specification and claims, the singular form "a", "an" and "the" include plural references unless the context clearly dictates otherwise.

[0037] As used herein, the term "comprising" is intended to mean that the compositions and methods include the recited features, but do not exclude other features. "Consisting essentially of" shall mean excluding other features of any essential significance to the combination. Thus, compositions consisting essentially of a plurality of halogenated carbon compounds would not exclude trace contaminants from the preparation, isolation and purification method and pharmaceutically acceptable carriers. As it relates to methods, “consisting essentially of’ shall mean excluding other steps of any essential significance to the combination. "Consisting of" shall mean excluding more than trace elements of other ingredients and substantial method steps. Embodiments defined by each of these transition terms are within the scope of this disclosure.

[0038] The term "about" or "approximately" means within an acceptable range for the particular value as determined by the person skilled in the art, which will also depend, at least in part, on how the value is measured or determined, e.g., the limitations of the measurement system.

[0039] Where a range of values is provided, it is understood that each intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the disclosure. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the disclosure, subjectto any specifically excluded limit in the stated range. Where the stated range includes one or both of the limits, ranges excluding either of those included limits are also included in the disclosure.

[0040] Statistical analysis of the properties described herein may be carried out by standard tests, for example, t-tests, ANOVA, or Chi squared tests. Typically, statistical significance will be measured to a level of p=0.05 (5%), more preferably p=0.0l , p=0.00l , p=0.000l , p=0.00000l .

[0041] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by the person skilled in the art to which this disclosure belongs. All publications mentioned herein are incorporated by reference for the purpose of describing and disclosing methodologies, compositions and uses that may be used in connection with the presently described disclosure.

[0042] As above, the present inventors have surprisingly found that co-administering a methanogenesis inhibitor and a productivity modifier provides a synergistic effect on reducing methane production and reducing the acetate-to-propionate ratio. Acetate and propionate are two of the main short chain fatty acids formed by the gut bacteria. Reducing the ruminal acetate-to-propionate ratio (A:P ratio) can improve the efficiency of dietary energy utilization, also known as feed conversion efficiency. As such, a decrease in acetate-to-propionate ratio results in an increase in feed conversion efficiency.

[0043] Thus, in a first aspect, the present disclosure provides a method of reducing methane production and increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

[0044] In a second aspect, there is provided a method of reducing methane production in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

[0045] In a third aspect, there is provided a method of increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

[0046] The methods disclosed may achieve both of a synergistic reduction methane production and a synergistic increase in feed conversion efficiency in a ruminant or only one of these, depending upon the particular methanogenesis inhibitor and the productivity modifier. In some embodiments, an enhanced reduction methane production and increase in feed conversion efficiency in a ruminant or only one of these, may be considered as representing synergism between a methanogenesis inhibitor and a productivity modifier by, for example, determining a combination index (CI) value according to any of the methodologies well known to the person skilled in the art, including the Chou-Talaly method (Chou TC et al., Trends Pharmacol Sci 4:450-454, 1983), and such that a CI value of <1 indicates a synergistic interaction between the methanogenesis inhibitor and the productivity modifier.

[0047] The methanogenesis inhibitor comprises one or more halogenated carbon compound. Without wishing to be bound by theory, it is thought that methanogens rely on the Wolfe cycle for formation of methane, in which carbon dioxide (CO2) is being reduced to methane (CH4) using hydrogen (H2). The important steps of the reaction are catalysed by methyl coenzyme M reductase and methyl coenzyme M transferase. The one or more halogenated carbon compound competes with substrates of the two enzymes and inhibits the methyl transfer and the release of methane from methyl coenzyme M.

[0048] The productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof. Without wishing to be bound by theory, it is thought that the ionophore may transport sodium cations across lipid bilayers of microbes and cause a bactericidal change in pH. A bactericidal effect on gram positive bacteria and protozoa decreases the amount of hydrogen being produced which primarily results in lower methane and acetate formation. Ionophores, such as Monensin A, are primarily active against gram positive bacteria, since their cell wall is more susceptible as compared to those of gram negatives. Ionophores, such as Monensin A, may also be used to treat coccidiosis caused by protozoal genera such as Eimera and Coccidium.

[0049] The succinate / propionate pathway compound is involved in the succinate / propionate pathway. In most microbes, malate is dehydrated to fumarate, fumarate is reduced to succinate and then decarboxylated to propionate. Without wishing to be bound by theory, it is thought that the addition of fumarate, malate and other carboxylic acids that are precursors of propionate (or the addition of propionate) help to increase the level of propionate in the rumen, while simultaneously lowering methane emissions by consumption of hydrogen.

[0050] A reduction in methane production may be measured relative to a ruminant that has not been administered with the methanogenesis inhibitor and the productivity modifier. In certain embodiments, the methods of the disclosure reduce the volume of methane produced from ruminants by at least about 5%; at least about 10%; at least about 15%; at least about 20%; at least about 25%; at least about 30%; at least about 35%; at least about 40%; at least about 45%; at least about 50%; at least about 55%; at leastabout 60%; at least about 65%; at least about 70%; at least about 75%; at least about 80%; at least about 85%; at least about 90%; at least about 95%; or at least about 100%. For example, the reduction might be at least about 40%.

[0051] The increase in feed conversion efficiency may improve various aspects of ruminant productivity. These may result from, e.g., encouragement of non-methanogenic microbiological pathways, which generate volatile fatty acids from excess hydrogen, rather than methane. For example, an increase in fumarate, malate or succinate, which generates propionate and / or medium-chain fatty acids (e.g. valerate and / or caproate) from excess hydrogen, rather than methane. Therefore, a reduction in methanogenic activity may be accompanied by an increase in microbial activity producing propionate and / or mediumchain fatty acids (e.g. valerate and / or caproate) and / or an increase in propionate- and / or medium-chain fatty acid-producing (e.g. valerate -producing and / or caproate -producing) microorganism populations in the rumen. The increase in feed conversion efficiency may be measured relative to a ruminant that has not been administered with the methanogenesis inhibitor and the productivity modifier.

[0052] In certain embodiments, the improving various aspects of ruminant productivity include increasing milk production, increasing ruminant weight gain, improving milk quality from the ruminant, increasing volatile fatty acid content in the stomach (e.g. rumen) of the ruminant, reducing finishing times for the ruminant (e.g. beef cattle), improving carcass quality, improving feed efficiency, and / or improving a feed recuperation ratio. In some embodiments, any such improvement might be measured relative to a ruminant which is not subject to the methods, compositions, or uses of the disclosure.

[0053] In preferred embodiments, the methods of the disclosure lead to an increase in one of the above aspects of ruminant productivity (or feed conversion efficiency) by at least about 1%, at least about 2%, at least about 3%, at least about 4%, at least about 5%; at least about 6%, at least about 7%, at least about 8%, at least about 9%, at least about 10%; at least about 15%; at least about 20%; at least about 25%; at least about 30%; at least about 35%; at least about 40%; at least about 45%; at least about 50%; at least about 55%; at least about 60%; at least about 65%; at least about 70%; at least about 75%; at least about 80%; at least about 85%; at least about 90%; at least about 95%; or at least about 100%. For example, the increase might be at least about 10%.

[0054] As mentioned above, a decrease in acetate-to-propionate ratio results in an increase in feed conversion efficiency. As such, acetate-to-propionate ratio may serve as a proxy for feed conversion efficiency. In certain embodiments, a decrease (or reduction) in in acetate-to-propionate ratio is between about 0.1 and 1, for example, between 0.1 and 0.8, 0.2 and 0.7, 0.3 and 0.6, or 0.4 and 0.6. As would be appreciated by the person skilled in the art, acetate values may be divided by propionate values to provide the acetate to propionate ratio. The difference in acetate propionate ratio can be plotted as reduction in acetate propionate ratio if the treatments resulted in decrease over the control. A useful formula is:Decrease in acetate / propionate ratio = (Control Acetate level / Control Propionate level) - (Treatment Acetate level / Treatment Propionate level)The result is a positive value if the treatment caused a decrease. E.g. if control sample 1 had acetate / propionate of 1.903, treatment sample 1 had an acetate / propionate of 1.852, then the reduction is 0.051.

[0055] The methods of the disclosure normally comprise oral co-administration of the methanogenesis inhibitor and the productivity modifier. The methanogenesis inhibitor and the productivity modifier can be co-administered with food as a supplement to the ruminant's diet (e.g. as a feed additive), or as a bolus whereby the ruminant is administered the methanogenesis inhibitor and the productivity modifier separately from food; or the methanogenesis inhibitor and the productivity modifier may be formulated as a composition which may itself be an animal food product.

[0056] Accordingly, in certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered simultaneously to the ruminant. As such, in some embodiments, the methanogenesis inhibitor and the productivity modifier may be separate and administered simultaneously. The term “administered simultaneously” or “co-administered” may include administration within a single feeding session, e.g., within 30, 20 or 10 minutes, such as within 9, 8, 7, 6, 5, 4, 3, 2, 1 minute or less. Coadministering the methanogenesis inhibitor and the productivity modifier to the ruminant may be considered a dose of the methanogenesis inhibitor and the productivity modifier.

[0057] As above, in certain embodiments, the methanogenesis inhibitor and the productivity modifier are formulated together, for example, as a composition or as a bolus.

[0058] As such, in a fourth aspect, there is provided a composition for reducing methane production and increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway.

[0059] In a fifth aspect, there is provided a composition for reducing methane production in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway.

[0060] In a sixth aspect, there is provided a composition for increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein themethanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway.

[0061] As would be appreciated by the person skilled in the art, the compositions of the disclosure can be administered in the methods of the disclosure. As such, references to co-administering a methanogenesis inhibitor and a productivity modifier include administering a composition of the disclosure, which contains the methanogenesis inhibitor and a productivity modifier. Further, reference to “a dose” includes the composition of the disclosure or a dose of a composition of the disclosure.

[0062] As above, the methanogenesis inhibitor comprises one or more halogenated carbon compounds. In certain embodiments, the methanogenesis inhibitor comprises a plurality of halogenated carbon compounds. In certain embodiments, the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform, bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3,3-dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, l,l,3,3-tetrabromopropan-2-ol, tribromomethanol, 1,1,3,3-tetrabromoacetone, 1,3- dichloroacetone, 1 , 1 ,3,3-tetrabromopropan-2-one, 1 , 1 ,3,3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3- chloropropan-2-one, 1 , 1 ,3-tribromopropan-2-one, 1 , 1 ,3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3- en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3- iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1 ,3-dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 - chloropropan-2-one, l,3-dibromopropan-2-one, l,3-dichloropropan-2-one, l-bromo-1,3,3- trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 -bromo-3-chloropropan-2-one, 1 -chloro-3- iodopropan-2-one, 3-bromo-l,l-dichloropropan-2-one, 2,2,2-tribromoacetic acid (ethyl ester), 2,2- dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2, 2 -dibromoacetic acid (methyl ester), 2-bromo- 2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3- dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid (methyl ester), 3-bromo-2- iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2,2-dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes, a-snyderol, [3-snyderol, y-snyderol, halogenated fatty acids, 3-bromo-2-heptanoic acids and 3-bromo-2- nonanoic acids, halogenated oxylipins, chlorinated egregiachloride A, chlorinated egregiachloride B, chlorinated egregiachloride C, chlorinated eiseniachloride A, chlorinated eiseniachloride B, chlorinated eiseniachloride C, iodinated eiseniaiodide A, iodinated eiseniaiodide B, halogenated terpenoids(e.g., diterpenes and triterpenes), halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan-2-ones or halogenated phenols. In particular embodiments, the methanogenesis inhibitor comprises bromoform.

[0063] In certain embodiments, the plurality of halogenated carbon compounds (e.g. a cocktail of halogenated products) may be generated by contacting a microorganism expressing one or more polynucleotides encoding one or more vanadium-dependent haloperoxidase enzymatic proteins with a source of electron-rich carbon compounds (which may be present in organic materials, such as biomass), a source of vanadium ions, a source of halides, and a source of peroxide, under conditions and for a time sufficient to produce the halogenated carbon compounds. Alternatively, the plurality of halogenated carbon compounds (e.g. a cocktail of halogenated products) may be generated by contacting a source of electron-rich carbon compounds with a composition comprising or consisting of hypohalite ions in the absence of a haloperoxidase under conditions and for a time sufficient to produce the plurality of halogenated carbon compounds.

[0064] As above, the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof. In certain embodiments, the ionophore comprises a poly ether ionophorous antibiotic. In certain embodiments, the ionophore comprises one or more of Lasalocid A, Monensin A, Narasin A, Salinomycin, Nigericin, Lenoremycin, Septamycin, Carriomycin, Antibiotic X-14766A, Noboritomycin A, Alborixin, lonomycin, Calcimycin, A23187), X14547 A, Lysocellin, Grisorixin, Lonomycin A, Octacyclomycin, X- 14931 A, Dianemycin, Lonomycin B, Lonomycin C, Antibiotic 6016, Inostamycin, Inostamycin B, Leuseramycin, Noboritomycin B, Mutalomycin, Laidlomycin, X-14885, Cationomycin A, AntibioticX-206, K-41-A, Hawaiimycin I, Maduramycin, CP-82,009, CP-84,657, CP-80,219, Kijimicin, Endusamycin, X-14868A, X-14868B, SF 2361, SF2324, SF 2487, Monensin B, A 28695B, A-204, Deoxy-(0-8)-salinomycin, CP-91,243, CP- 120,509, Iso-lasalocid, 20-Deoxynarasin, 20-deoxy-epi-17-narasin, Moyukamycin, (Deoxy-(O-8)3)-epi-17 salinomycin, CP-54,883, X-14868C, X-14868D, Abierixin, Martinomycin, Portmicin, X-14667 A, X- 14667 B, CP-96,797, or UK-58, 852. In certain embodiments, the ionophore comprises one or more of lasalocid A or monensin A. In certain embodiments, the ionophore comprises monensin A. In certain embodiments, the ionophore consists of monensin A. In certain embodiments, the succinate / propionate pathway compound comprises one or more of a substrate, intermediate or product of the succinate / propionate pathway. This may be referred to as a succinate / propionate pathway compound. In certain embodiments, the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate. In certain embodiments, the succinate / propionate pathway compound comprises fumarate. In certain embodiments, the succinate / propionate pathway compound consists of fumarate. As would be appreciated by the person skilled in the art, references to deprotonated compounds, such as malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate may include the protonated forms, malic acid, fumaric acid, aspartic acid, lactic acid, pyruvic acid, oxaloacetic acid, succinic acid, or propionic acid, unless indicated otherwise by context. In certain embodiments, the productivity modifier comprises monensin A. In certain embodiments, the productivity modifier comprises fumarate. In certain embodiments, themethanogenesis inhibitor is co-administered with both one or more ionophore and one or more succinate / propionate pathway compound. In certain embodiments, the methanogenesis inhibitor is coadministered with both monensin A and fumarate.

[0065] When the methanogenesis inhibitor and the productivity modifier are in a bolus, the methods of the disclosure comprise the step of oral administration of the bolus. When the methanogenesis inhibitor and the productivity modifier are a food supplement (or additive), the methods of the disclosure comprise the steps of (i) adding the methanogenesis inhibitor and the productivity modifier to food and (ii) oral administration (consumption) of the food. When the methanogenesis inhibitor and the productivity modifier are in the form of animal feed, the administration in the methods of the disclosure comprises the step of feeding the ruminant (which encompasses any normal feeding techniques such as allowing the ruminant to feed itself). In certain embodiments, the methanogenesis inhibitor and the productivity modifier are formulated with the meal. In some embodiments, co-administering the methanogenesis inhibitor and the productivity modifier is the animal feeding. In particular embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered with the meal. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered within 30 minutes or within 20 minutes or within 10 minutes of the consumption of a meal. In some embodiments the ruminants' diet consists of a combination of grazing and feeding, and the methanogenesis inhibitor and the productivity modifier are co-administered during the feeding.

[0066] In some embodiments, the methods of the disclosure involve administration of the methanogenesis inhibitor and the productivity modifier (e.g. bolus), in a manner similar to administration of a medicament. Sometimes the ruminant's diet consists of (or essentially of) feed including the methanogenesis inhibitor and the productivity modifier.

[0067] In certain embodiments, the methanogenesis inhibitor and the productivity modifier are coadministered at substantially regular intervals. For example, the interval between subsequent administration of compositions might be about 24 hours. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered once daily. In some such embodiments, when co-administered daily, the interval between subsequent administration of the methanogenesis inhibitor and the productivity modifier might be about 24 hours. In some embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered more frequently than once daily. In certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered at least twice per day. As such, in certain embodiments, the methanogenesis inhibitor and the productivity modifier are co-administered at least every 12, 18, 24, 30, 36, 40 or 48 hours. In certain embodiments, a ruminant may be co-administered at or around feeding times. In certain embodiments, a ruminant may be provided with access to the methanogenesis inhibitor and the productivity modifier at regular intervals or irregular intervals, such as at least every 12, 18, 24, 30, 36, 40 or 48 hours.

[0068] A dose of the methanogenesis inhibitor and the productivity modifier (e.g. the composition) can be adjusted based on the amount of feed given to the ruminant, on the ruminant’s weight, on the desired rumen concentration of the methanogenesis inhibitor and the productivity modifier, or on a desired decrease in methane production from the ruminant or a desired decrease in the acetate to propionic acid ratio in the rumen of the ruminant. For instance, a particular amount of the methanogenesis inhibitor and the productivity modifier might be added per kg of feed, in order to control the amount of the methanogenesis inhibitor and the productivity modifier co-administered to the ruminant. Therefore, in certain embodiments, the methods include steps of (i) mixing the methanogenesis inhibitor and the productivity modifier with food and (ii) oral administration of the food to the ruminant. In certain embodiments, the composition can itself comprise food. In certain embodiments, the composition forms part of the ruminant’s diet. In some embodiments, the composition includes enough food to constitute the ruminant's entire diet.

[0069] The methods of the disclosure may comprise co-administering the methanogenesis inhibitor and productivity modifier (e.g. a composition of the disclosure) to the ruminant in a particular dosage, wherein the dosage is adjusted to provide a particular concentration of the methanogenesis inhibitor and productivity modifier in the digestive tract of the ruminant (e.g. rumen of the ruminant). As would be appreciated by the person skilled in the art, the concentration of the methanogenesis inhibitor and productivity modifier can be measured by conventional means, such as analysis of a rumen fluid sample using gas chromatography (GC) with the detectors such as mass spectrometry (MS) or flame ionization detection (FID), using liquid chromatography (LC) in combination with different detectors such as MS, diode array detection (DAD), refractive index detection (RID) or evaporative light scattering detection (ELSD) or using nuclear magnetic resonance (NMR). The methods of the disclosure may comprise coadministering the methanogenesis inhibitor and productivity modifier (e.g. a composition of the disclosure) to the ruminant in a particular dosage, wherein the dosage is adjusted to provide one or more of a particular decrease in methane production from the ruminant or a particular decrease in the acetate to propionic acid ratio in the rumen of the ruminant. As would be appreciated by the person skilled in the art, methane production can be measured by conventional means, such as the use of respiration chambers, the sulphur hexafluoride (SF6) tracer technique, breath sampling during milking or feeding, the GreenFeed system, or using a laser methane detector. As would be appreciated by the person skilled in the art, the acetate to propionic acid ratio in the digestive tract (e.g. stomach, e.g. rumen) can be measured by conventional means, such as GC-MS, GC-FID, LC-MS, LC-DAD, LC-RID, LC-ELSD or NMR analysis of a rumen fluid sample.

[0070] In certain embodiments, there is provided a step of determining a dose comprising coadministering the methanogenesis inhibitor and productivity modifier (e.g. a composition of the disclosure) to the ruminant, measuring the concentration of the methanogenesis inhibitor and productivitymodifier in the rumen of the ruminant, and adjusting the dose of the methanogenesis inhibitor and productivity modifier to achieve a desired rumen concentration of the methanogenesis inhibitor and the productivity modifier. The rumen concentration of the methanogenesis inhibitor and the productivity modifier can be measured by conventional means, such as GC-MS, GC-FID, LC-MS, LC-DAD, LC-RID, LC-ELSD or NMR analysis of a rumen fluid sample.

[0071] In certain embodiments, there is provided a step of determining a dose comprising coadministering the methanogenesis inhibitor and productivity modifier (e.g. a composition of the disclosure) to the ruminant, measuring the effect on one or more of methane production or acetate to propionic acid ratio in the rumen, and adjusting the dose of the composition to achieve a desired decrease in methane production or a particular decrease in the acetate to propionic acid ratio in the rumen of the ruminant. The methane production and the acetate to propionic acid ratio in the digestive tract (e.g. stomach, e.g. rumen) can be measured by conventional means, as described elsewhere in this disclosure.

[0072] In certain embodiments, there is provided a step of determining a dose comprising weighing the ruminant a first time, co-administering the methanogenesis inhibitor and productivity modifier (e.g. a composition of the disclosure) to the ruminant on a plurality of occasions, weighing the ruminant a second time, and adjusting the dose of the methanogenesis inhibitor and productivity modifier to achieve a desired weight gain.

[0073] As would be appreciated by the person skilled in the art, an amount or concentration of the methanogenesis inhibitor and productivity modifier in a dose will depend on the dosage form. For example, a dose in the form a medicament may be concentrated, whereas a dose in the form of a feed may be dilute. The dose may be calculated as a daily dose. For example, the daily dosage of methanogenesis inhibitor and productivity modifier may be the same, whether administered as, e.g., a medicament or as a feed.

[0074] The co-administering in the methods and administering in the compositions of the disclosure may involve dosing according to dry matter intake. Ruminants, such as cattle and sheep, generally consume between 2-3% of their live weight in dry matter daily. There may be small variations in diet due to age, species, and / or activity of the ruminant. Based on the expected daily dry matter intake, the amount of the methanogenesis inhibitor and productivity modifier can be calculated.

[0075] In certain embodiments, the co-administering (e.g. a dose of the composition) comprises administering about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI) of the methanogenesis inhibitor, for example, 20 to lOOmg per kg DMI, 30 to 90mg per kg DMI, 40 to 80 mg per kg DMI, 50 to 150mg per kg DMI, 40 to 120mg per kg DMI or 80 to 120mg per kg DMI. In particular embodiments, the co-administering comprises administering about 63mg per kg DMI of themethanogenesis inhibitor or about lOOmg per kg DMI of the methanogenesis inhibitor. As such, when coadministering 63mg per kg DMI of the methanogenesis inhibitor, a 500kg steer consuming 3% live weight of dry matter daily (ie 15kg dry matter daily), may be administered 945 mg of methanogenesis inhibitor. In certain embodiments, the co-administering comprises administering about 5 to 150mg per kg DMI of the ionophore, for example, 5 to lOOmg per kg DMI, 10 to 60mg per kg DMI, 10 to 40mg per kg DMI or 20 to 40mg per kg DMI. In particular embodiments, the co-administering comprises administering about 22mg per kg DMI of the ionophore or about 34.6mg per kg DMI of the ionophore. In certain embodiments, the co-administering comprises administering about 0.2 to 20g per kg DMI succinate / propionate pathway compound, for example, 0.5 to 10g per kg DMI, 0.5 to 8g per kg DMI, 1 to 5g per kg DMI, 1 to 4g per kg DMI, 1 to 3g per kg DMI or 2 to 3g per kg DMI. In particular embodiments, the co-administering comprises administering about 2g per kg DMI of the succinate / propionate pathway compound or about 3g per kg DMI of the succinate / propionate pathway compound, eg, about 2.8g per kg DMI of the succinate / propionate pathway compound.

[0076] The co-administering in the methods and administering in the compositions of the disclosure may involve dosing according to body weight of the ruminant. A 500kg steer consuming 2-3% live weight of dry matter daily will consume about 10-15kg dry matter daily. Therefore, the steer may be administered, e.g., 20 to lOOmg per kg DMI methanogenesis inhibitor, and 5 to 150mg per kg DMI of the ionophore or 0.2 to 20g per kg DMI succinate / propionate pathway compound, which is 200-1500mg methanogenesis inhibitor, and 50-2250mg ionophore or 2-300g succinate / propionate pathway compound. On a kg body weight basis, the steer consumes 0.4-3mg methanogenesis inhibitor per kg body weight, and 0.1-4.5mg ionophore per kg body weight or 4-600mg succinate / propionate pathway compound.

[0077] In embodiments in which the ruminant consumes 2% live weight of dry matter daily, a dose or composition (e.g. daily dose) comprises 0.4-2mg methanogenesis inhibitor per kg body weight. In certain embodiments, a dose or composition (e.g. daily dose) comprises 0.6-1.8, 0.8-1.6, 1-1.4 or 1.26mg methanogenesis inhibitor per kg body weight. In certain embodiments, a dose or composition comprises 0.1-3 mg ionophore per kg body weight. In certain embodiments, a dose or composition comprises 0.2-2, 0.4-1.2, 0.6-0.8 or 0.69mg ionophore per kg body weight. In certain embodiments, a dose or composition comprises 4-400mg succinate / propionate pathway compound. In certain embodiments, a dose or composition comprises 10-200, 10-100, 20-80, 20-60 or 40 to 80mg succinate / propionate pathway compound.

[0078] In embodiments in which the ruminant consumes 3% live weight of dry matter daily, a dose (e.g. daily dose or composition) comprises 0.6-3mg methanogenesis inhibitor per kg body weight. In certain embodiments, a dose (e.g. daily dose or the composition) comprises 0.9-2.7, 1.2-2.4. 1.5-2.1 or 1.89mg methanogenesis inhibitor per kg body weight. In certain embodiments, a dose or composition comprises 0.15-4.5mg ionophore per kg body weight. In certain embodiments, a dose or composition comprises 0.3-3, 0.6-1.8, 0.9-1.2 or 1.04mg ionophore per kg body weight. In certain embodiments, a dose or composition comprises 6-600mg succinate / propionate pathway compound. In certain embodiments, a dose or composition comprises 15-300, 15-150, 30-120, 45-90 or 60mg succinate / propionate pathway compound.

[0079] The co-administering in the methods and administering in the compositions of the disclosure may involve dosing according to the desired rumen concentration of the methanogenesis inhibitor and productivity modifier. The person skilled in the art could readily calculate the rumen concentration. For example, a 500kg steer with a rumen volume of about 100 litres has about a 40-litre liquid volume and consumes about 3% of its body weight in feed, so the dry matter intake (DMI) is approximately 15kg (3% of 500kg). If administered lOOmg per kg DMI of bromoform, the dosage is 1.5g (lOOmg / kg x 15) and given that bromoform has a molar mass of about 252.73g / mol, the concentration would be about 0.15mM. If administered 22mg per kg DMI of Monensin A, the dosage is 330 milligrams (22mg / kg x 15kg) and given that Monensin A has a molar mass of about 670.88g / mol, the concentration would be about 0.0123mM. If administered 2.8g per kg DMI of the fumarate, the dosage is 42 grams (2.8 g / kg x 15 kg) and given that fumarate has a molar mass of about 116.07g / mol, the concentration would be about 9mM.

[0080] In other embodiments, the co-administering provides a rumen concentration of the methanogenesis inhibitor of 2-10uM, for example, 2-8uM, 3-7uM, or 4-6uM. In particular embodiments, the co-administering provides a rumen concentration of the methanogenesis inhibitor of about 5uM. As such, in certain embodiments, a dose of the composition provides a rumen concentration of the methanogenesis inhibitor of 2-10uM, -8uM, 3-7uM, 4-6uM or about 5uM. In certain embodiments, the co-administering provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM, for example, 150-550mM, 200-500mM, 250-450mM, or 300-400mM. In particular embodiments, the co-administering provides a rumen concentration of the succinate / propionate pathway compound of about 344mM. As such, in certain embodiments, a dose of the composition provides a rumen concentration of the succinate / propionate pathway compound of 100-600mM, 150-550mM, 200- 500mM, 250-450mM, 300-400mM, or about 344mM. In certain embodiments, the co-administering provides a rumen concentration of the ionophore of about 0.2 to about 20uM, for example, 0.5-15uM, 5- 15uM, 0.5-10uM, 0.5-8uM, l-5uM, l-4uM, or l-3uM. In particular embodiments, the co-administering provides a rumen concentration of the ionophore of about 2uM. As such, in certain embodiments, a dose of the composition provides a rumen concentration of the ionophore of 0.2-20uM, 0.5-10uM, 0.5-8uM, 1- 5uM, l-4uM, l-3uM, or about 2uM. The rumen concentration of the methanogenesis inhibitor and the productivity modifier can be measured by conventional means, such as GC-MS, GC-FID, LC-MS, LC- DAD, LC-RID, LC-ELSD or NMR analysis of a rumen fluid sample.

[0081] The co-administering in the methods and administering in the compositions of the disclosure may involve dosing according to the desired molar ratio of the methanogenesis inhibitor and productivity modifier. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:120, for example, about 1:40 to about 1:100, about 1:50 to about 1:90, about 1:50 to about 1:80, about 1:50 to about 1:70, or about 1:60 to about 1:70. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:68 or 1:61. As such, in certain embodiments, the compositions of the disclosure comprise a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound of about 1:20 to about 1:120, about 1:40 to about 100, about 1:50 to about 1:90, about 1:50 to about 1:80, about 1:50 to about 1:70, or about 1:60 to about 1:70, about 1:61 or about 1:68. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 20:1 to about 1:1, for example, about 15:1 to about 2:1, about 10:1 to about 3:1, about 12:1 to about 5:1 or about 8:1 to about 2:1. In certain embodiments, a molar ratio of the methanogenesis inhibitor to the ionophore is about 5:1 or about 12:1. As such, in certain embodiments, the compositions of the disclosure comprise a molar ratio of the methanogenesis inhibitor to the ionophore of about 20:1 to about 1:1, about 15:1 to about 2:1, about 10:1 to about 3:1, about 12:1 to about 5:1, about 8:1 to about 2:1, about 12:1 or about 5:1.

[0082] As would be appreciated by the person skilled in the art, an initial dose or doses could be higher and subsequent doses could be reduced. This could be to, e.g., obtain and the maintain a specific concentration of the rumen concentration of the methanogenesis inhibitor and the productivity modifier. In certain embodiment, a subsequent dose is reduced by about 5, about 10, about 20, about 30, about 40, or about 50%. For example, a daily dose could be reduced by about 5, about 10, about 20, about 30, about 40, or about 50%. In certain embodiment, a length of time between doses in increased in order to reduce the daily dose. As would be appreciated by person skilled in the art, the molar ratio of methanogenesis inhibitor and productivity modifier could be maintained, while the dose is reduced.

[0083] As mentioned elsewhere herein, the composition of the disclosure may be, e.g., a bolus or medicament, a feed supplement (or additive), or a feed. As such, an amount or concentration of the methanogenesis inhibitor and the productivity modifier will differ, depending upon the form of the composition. However, as would be appreciated by the person skilled in the art, the overall dosage may be the same.

[0084] In certain embodiments, the compositions of the disclosure are in solid or liquid form. In certain embodiments when the compositions are in a solid form, the compositions may comprise a coating. Alternatively, the compositions may alternatively be a capsule. The coating may serve various functions, e.g., reducing degradation of the methanogenesis inhibitor and productivity modifier, improving storage stability, or providing controlled release, e.g. delayed and / or sustained release. A coated composition maybe provided by first preparing the composition in a solid form and then coating the composition. Useful coatings comprise at least one of the following: acrylic acid, alginate, beta-cyclodextrin, cyanoacrylate, ethyl cellulose, gylcerin, glycerol, hard fat, hydroxyethyl methacrylate-oligo(hydroxybutyrate), isobutyleneisoprene 20 copolymers, methacrylamide chitosan, milk powder, N-isopropylacrylamide (NI PA Am), poly (methyl methacrylate) capsulation, oils (e.g. vegetable / seed oils, coconut oil, canola oil), poly(D,L-lactide-co-glycolide) (PLGA), poly(vinyl pyrrolidone) (PVP), polydimethylsiloxane (PDMS), polyisobutylene, polyvinyl acetate, polyisoprene, polyethylene, silica hydrogels, sodium alginate, styrenebutadiene copolymers, vinyl acetate, and combinations thereof. Such coatings can be used individually, or in combination. A liquid composition may comprise a carrier, such water or oil. The methanogenesis inhibitor and productivity modifier may be dissolved or suspended in the carrier, as appropriate. In certain embodiments, the oil is an edible oil, as such a vegetable / seed oil (e.g. canola oil).

[0085] In some embodiments, a composition of the disclosure is in the form of a bolus and the composition comprises conventional excipients for a bolus for ruminants. Useful excipients comprise, for example, iron oxide, zinc oxide, magnesium stearate, hydrogenated fat, or combinations thereof (e.g. all of these). A bolus may optionally include a casing, and / or a coating. Administration of a bolus may be on a regular basis, e.g., monthly, weekly, bi-weekly or as described elsewhere herein.

[0086] In some embodiments, a composition of the disclosure is in the form of a feed supplement (or additive). A feed supplement may be suitable for adding to food prior to consumption. In certain embodiments, the feed supplement comprises additional feed components. Useful feed components comprise, for example, oats, maize, barley, soya, dried distiller’s grain (DDGs) and / or molasses. In certain embodiments, the feed supplement is in the form of a pellet or powder. The feed supplement may be incorporated into a concentrate ration or a feed nut. In some embodiments, the composition is in the form of a feed that is suitable for the animal's entire diet.

[0087] In some embodiments, such as when a composition of the disclosure is in the form of a medicament, the composition comprises a pharmaceutically acceptable carrier and / or diluent such as water, saline, an emulsion, a gel, a hydrogel, or a solid for pellets. In some embodiments, the composition comprises one or more excipients. Useful excipients comprise, for example, anti-adherents, binders, density adjusters, water soluble bulking agents, water insoluble bulking agents, coatings, colouring, disintegrants, flavourings, glidants, lubricants, preservatives, sorbents, sweeteners, and polymers. In certain embodiments, the compositions of the disclosure are provided in aqueous solution, in saline solution, as an emulsion, as a gel, as a hydrogel, as a paste, in an oil, as a pellet, or as a powder.

[0088] As the person skilled in the art would appreciate, the present disclosure may be useful in ruminants that are raised for food production. In certain embodiments, the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae. In certain embodiments, theruminant is one or more of mouse-deer, deer, moose, giraffe and okapi, pronghorn, musk deer, cattle, goats, sheep, llama, alpaca, bison, elk, reindeer, yak, camel or antelope. In particular embodiments, the ruminant is one or more of cattle or sheep.

[0089] In some embodiments, the ruminant has been silage fed prior to consuming a composition of the disclosure or being subject to a method of the disclosure. In some embodiments, the ruminant has been pasture-fed prior to consuming a composition of the disclosure or being subject to a method of the disclosure. In some embodiments, the ruminant is being fed a balanced ration or a concentrated feed prior to consuming a composition of the disclosure or being subject to a method of the disclosure. In some embodiments, the ruminant is fed by outdoor grazing on land prior to consuming a composition of the disclosure or being subject to a method of the disclosure.

[0090] In certain embodiments, the methanogenesis inhibitor and the productivity modifier in combination when administered to a ruminant synergistically increase productivity / feed conversion efficiency or decrease methane emissions in said ruminant as compared to an additive effect of administering to a ruminant the methanogenesis inhibitor or the productivity modifier individually.

[0091] In a seventh aspect, there is provided a method of increasing productivity in a ruminant, comprising administering a therapeutically effective amount of the composition of the disclosure to the ruminant. As such, the method encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. As used herein, a therapeutically effective amount may be an amount that provides a statistically significant effect relative to an untreated ruminant. The amount of the composition administered can be determined using any of the dosages or dosage forms disclosed herein.

[0092] In certain embodiments, productivity is measured by one or more of a reduction in methane production, an increase in feed conversion efficiency, an increase in weight gain or a reduction in an acetate-to-propionate ratio. The person skilled in the art would readily understand how to calculate these measures of productivity. For example, feed conversion efficiency is calculated based on feed consumed and weight gained by the ruminant and the acetate-to-propionate ratio may also serve as a proxy for feed conversion efficiency. A reduction in methane production, an increase in weight gain or a reduction in an acetate-to-propionate ratio may be determined conventionally and as described elsewhere herein.

[0093] In an eighth aspect, there is provided a method of decreasing the ratio of acetate to propionate in a ruminant, comprising administering a therapeutically effective amount of the composition of the disclosure to the ruminant. As such, the method encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. A decrease in an acetate-to-propionate ratio may be determined conventionally and as described elsewhereherein. The amount of the composition administered can be determined using any of the dosages or dosage forms disclosed herein.

[0094] In a ninth aspect, there is provided a method of increasing feed conversion efficiency in a ruminant, comprising administering a therapeutically effective amount of the composition of the disclosure to the ruminant. As such, the method encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. The amount of the composition administered can be determined using any of the dosages or dosage forms disclosed herein. Increasing feed conversion efficiency can be calculated as described elsewhere herein.

[0095] In a tenth aspect, there is provided a use of a methanogenesis inhibitor and a productivity modifier for reducing methane production and increasing feed conversion efficiency in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof. As such, the use encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. The amount of the methanogenesis inhibitor and a productivity modifier administered can be determined using any of the dosages or dosage forms disclosed herein. A reduction in methane production may be determined conventionally and as described elsewhere herein. Increasing feed conversion efficiency can be calculated as described elsewhere herein.

[0096] In an eleventh aspect, there is provided a use of a methanogenesis inhibitor and a productivity modifier for reducing methane production in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof. As such, the use encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. The amount of the methanogenesis inhibitor and productivity modifier can be determined using any of the dosages or dosage forms disclosed herein. A reduction in methane production may be determined conventionally and as described elsewhere herein.

[0097] In a twelfth aspect, there is provided a use of a methanogenesis inhibitor and a productivity modifier for increasing feed conversion efficiency in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof. As such, the use encompasses co-administering a therapeutically effective amount of the methanogenesis inhibitor and productivity modifier, as described elsewhere herein. The amount of the methanogenesis inhibitor and productivity modifier can be determined using any of the dosages or dosage forms disclosed herein. Increasing feed conversion efficiency can be calculated as described elsewhere herein.

[0098] In a thirteenth aspect, there is provided a methanogenesis inhibitor comprising one or more halogenated carbon compound, and a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, in the manufacture of a supplement or feed for reducing methane production and increasing feed conversion efficiency in a ruminant. In other aspects, the supplement or feed is for reducing methane production or increasing feed conversion efficiency in a ruminant. The animal feed supplement may be in any form that is suitable for feeding to an animal, particularly a ruminant. For example, the supplement may be a liquid (e.g., dissolved or suspended in a carrier, such as water), or a solid. Suitable solid forms include powders (e.g., dried, lyophilised, ground, milled), granulates, coated carriers (e.g., spray-dried granules), and the like. The animal feed may be in any form that is suitable for feeding to an animal, particularly a ruminant. The animal feed may be in the form of a block (e.g., a lick-block or a fat block), a blend (e.g., with a meal, such as rapeseed meal, flaxseed meal, cottonseed meal, soybean meal or cornmeal), or a diet supplement (such as a milk supplement), or added to the animal's normal drinking water (either dissolving or remaining suspended in the water). The supplement or feed may also be produced as described elsewhere herein or contain components described elsewhere herein, for example, with reference to the composition of the disclosure.

[0099] In a fourteenth aspect, there is provided a use of a methanogenesis inhibitor comprising one or more halogenated carbon compound, and a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, in the manufacture of a medicament for reducing methane production and increasing feed conversion efficiency in a ruminant. In other aspects, the medicament is for reducing methane production or increasing feed conversion efficiency in a ruminant. The medicament may be produced as described elsewhere herein or contain components described elsewhere herein, for example, with reference to the composition of the disclosure.

[0100] In a fifteenth aspect, there is provided an animal feed supplement, comprising the composition of the present disclosure. The supplement may be produced as described elsewhere herein or contain components described elsewhere herein, for example, with reference to the composition of the disclosure.

[0101] In a sixteenth aspect, there is provided an animal feed, comprising the composition of the present disclosure or the supplement of the present disclosure. The feed may be produced as described elsewhere herein or contain components described elsewhere herein.

[0102] In a seventeenth aspect, there is provided a kit comprising first and second containers, wherein the first container contains a methanogenesis inhibitor comprising one or more halogenated carbon compound, and the second container contains a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof; optionally packaged withinstructions for the use of the kit in a method of the disclosure. As would be appreciated by the person skilled in the art, the methanogenesis inhibitor and the halogenated carbon compound may be prepared or formulated as described elsewhere herein, for example, with reference to the composition, feed supplement or medicament of the disclosure.

[0103] In an eighteenth aspect, there is provided a method for managing methane emissions and weight gain in ruminant animals, comprising: (a) administering to the ruminant animal an effective amount of a methanogenesis inhibitor comprising one or more halogenated carbon compound, wherein the administration of the methanogenesis inhibitor results in a reduction in the weight gain of the animal and a reduction in methane emissions from the animal; and (b) co-administering to the ruminant animal an effective amount of a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, wherein the productivity modifier at least partially recovers the reduction in weight gain caused by the methanogenesis inhibitor, without negating the reduction in methane emissions achieved by the methanogenesis inhibitor.

[0104] A high dose of a methanogenesis inhibitor can result in a reduction in weight gain. The method is useful for at least partially recovering the reduction in weight gain (eg reducing the weight loss) caused by administration of a methanogenesis inhibitor. As would be appreciated by the person skilled in the art, the reduction in weight gain is relative to a ruminant fed a regular feed (eg control feed) without the methanogenesis inhibitor. In certain embodiments, the reduction in weight gain caused by administering the methanogenesis inhibitor is at least about 1%, for example, between about 1% and 50%, about 1% and about 40%, about 1% and about 30%, about 1% and about 20%, about 5% and about 40%, or about 10% and 40%. In particular embodiments, the reduction in weight gain caused by administering the methanogenesis inhibitor may be about 36%. In certain embodiments, the coadministering of the productivity modifier causes that reduction to be reduced by at least three quarter (0.75), by at least half (0.5) or by at least one quarter (0.25). In particular embodiments, the coadministering of the productivity modifier causes that reduction to be reduced by at least half (0.5. For example, if the reduction in weight gain is about 50%, then that is reduced to about 25%. In certain embodiments, the reduction in weight gain is reduced to at least 0.5%, for example, between about 1.5% and 25%, about 2.5% and about 20%, about 5% and about 20%, or about 5% and about 15%. In particular embodiments, the reduction in weight gain is reduced to about 14% by the productivity modifier. As such, if the total weight gain of a ruminant fed a control diet is 53.4kg, administering the methanogenesis inhibitor reduces the total weight gain to 34.1kg (eg about 36% reduction) and co-administering the productivity modifier partially recovers the reduction in weight gain so that the total weight gain is 45.8kg (eg reduction in weight gain is reduced to about 14%).

[0105] As would be appreciated by the person skilled in the art, the methanogenesis inhibitor and the halogenated carbon compound may be prepared or formulated as described elsewhere herein, for example, with reference to the composition, feed supplement or medicament of the disclosure.

[0106] The features of each aspect are to be understood as they are described elsewhere in this disclosure, unless indicated otherwise by context.EXAMPLES

[0107] Example 1

[0108] Methods

[0109] Preparation of in vitro rumen cultures

[0110] Rumen fluid was taken from a fistulated cow and processed on the same day.To simulate the rumen environment and test efficacy of treatments, anaerobic in vitro rumen cultures were prepared using air-tight headspace vials. 5ml cultures were prepared in 20ml crimp top headspace vials with butyl rubber stoppers. As feed, lOOmg of Rhodes grass was added to 3.4ml of in vitro rumen buffer (modified from Goering and Van Soest 1970). 300ul of reductant solution (312.5mg Cysteine hydrochloride, 312.5mg Sodium sulfate and 2ml of NaOH in 47.5ml of water) were reacted without any oxygen present in the vial. Treatments were added either as a solution, usually 300ul, or a as a powder, in which case 300ul of additional buffer was added. The treatments comprised: 5uM bromoform, luM monensin A, 0.2% fumaric acid (wt % of Rhodes grass inclusion), 5uM bromoform + luM monensin A and 5uM bromoform + 0.2% fumaric acid (wt % of Rhodes grass inclusion). Bromoform and monensin A can be shown as wt % of Rhodes grass inclusion, e.g., 5uM bromoform in 5ml of in vitro cultures is 6.313ug of bromoform. Since lOOmg Rhodes grass is used per vial as substrate, the concentration of bromoform is 63.13ug per gram of Rhodes grass. luM monensin A sodium salt is 34.6 ug per gram of Rhodes grass.

[0111] Vials were capped and purged with Nitrogen to ensure an oxygen-free environment before 1ml of rumen fluid and treatments (300ul) were added using a syringe. In vitro rumen samples were incubated for at least a day in a shaking incubator at 39° C and 150rpm before methane, CO2 and volatile fatty acids were analyzed using GC-MS.

[0112] To further track production of volatile fatty acids, in vitro rumen cultures were passaged after the first measurement on day 1. Passaging was performed by replacing 20% of existing in vitro rumen sample (1ml) with fresh buffer, lOOmg of Rhodes grass and one third of the initial treatmentamount. Volatile Fatty acids were analyzed for 3 consecutive passaging days. Methane values were only taken on day 1.

[0113] GC-MS analysis

[0114] Methane and CO2 were analyzed on a Shimadzu GC-MS (Shimadzu Nexis 2030 with TQ-8050NX) using a SH-Q-BOND PLOT Column (30Mx0.32mmxl0pm) and an AOC-6000 autosampler. 0.5ml of headspace gases were injected and analysed. The GC-MS was run isocratically for 2 min at 50° C and MS was operated in SIM mode with target ions m / z 15, 16 and 14 for methane. Methane levels of treatment samples were compared to controls without treatment to calculate the effect of methane inhibition.

[0115] Volatile Fatty acids were analyzed on the same machine on a SH-WAX column (30Mx0.25mmx0.25pm). 1ml of in vitro rumen cultures was esterified in headspace vials using 400ul of ethanol, 400ul of concentrated sulphuric acid followed by incubation for 45 min at 60° C before lOOul of headspace gas was injected into the GC-MS. Ethyl esters of acetate, propionate and butyrate were identified using SIM mode (Target ions for ethyl acetate: m / z 43 and 61, for ethyl propionate: m / z 29 and 57 and for ethyl butyrate: m / z 71 and 43). The GC was run at column flow of 1.02ml.min with the column being heated for 2 min at 40C before being increased 70C at lOC / min. After 5min the column is further heated to 80C at a rate of 25C / min before being held at 80C for 1.6min.

[0116] Fatty acid levels of treatment samples were quantified using a standard curve and compared to control without treatments.

[0117] References :

[0118] Goering, H. Keith, and Peter J. Van Soest. Forage fiber analyses (apparatus, reagents, procedures, and some applications). No. 379. US Agricultural Research Service, 1970.

[0119] Calculation of reduction of acetate to propionate ratio

[0120] For all samples, acetate values were divided by propionate values which gives the acetate to propionate ratio. The difference in acetate propionate ratio can be plotted as reduction in acetate propionate ratio if the treatments resulted in decrease over the control.

[0121] So in a formula that would be:Decrease in acetate / propionate ratio = (Control Acetate level / Control Propionate level)-(Treatment Acetate level / Treatment Propionate level)

[0122] That results in a positive value if the treatment caused a decrease. E.g. Control sample 1 had acetate / propionate of 1.903, bromoform sample 1 had an acetate / propionate of 1.852, hence the reduction is 0.051.

[0123] Each replicate is treated individually. The data presents the average of three replicates. The error bars are standard deviation.

[0124] Results

[0125] The effect of combining methanogenesis inhibitors and rumen modifiers promoting propionate formation was demonstrated using bromoform in combination with monensin A or fumarate in in vitro rumen cultures. In vitro rumen cultures were prepared from fresh rumen fluid collected on the day, rumen fluid buffer, reducing agents and hay (as described in the Methods above).

[0126] Methane formation was measured after 1 day of incubation and acetate and propionate were analysed either after 1 day or after 2 days with additional rumen buffer and hay added on day 1 (see passaging samples in methods).

[0127] Methane was analysed using headspace analysis and acetate and propionate were analysed using esterification of the rumen sample followed by headspace analysis on the GC (see methods for detail).

[0128] Bromoform and monensin A and bromoform and fumaric acid synergistically decrease methane emissions in vitro

[0129] Methane formation was measured in in vitro samples and compared to control samples to calculate the percentage of methane decrease. A combination of 5uM bromoform and luM monensin A, and 5uM bromoform and 0.2% fumaric acid (wt % of feed inclusion) resulted in a synergistic decrease in methane emissions (Figure 1). The observed effect of the combination of treatments was larger than the expected additive effect.

[0130] Bromoform and Monensin A synergistically lower acetate to propionate ratio in vitro

[0131] The acetate to propionate ratio in the rumen is inversely correlated with feed conversion efficiency. As such, a decrease in acetate to propionate ratio is associated with a better feed to weight gain in the cow. Since weight gain can only be measured in experiments involving live cows, a decrease of the acetate to propionate ratio is used as a proxy for improved feed conversion efficiency in in vitro rumen experiments.

[0132] At 5uM bromoform and luM monensin A, both additives together caused a synergistic decrease in the acetate to propionate ratio (Figure 2). The decrease is expressed as the change in the ratio as compared to controls.

[0133] In a more realistic scenario, bromoform and monensin A were administered over multiple days with an exchange of some of the liquid in the system and additional feed intake. This was tested by passaging the in vitro reactions (described in the Methods) in order to mimic the natural passaging of fluid and feed in the cow.

[0134] It was found in this continuous testing that the synergistic effect of bromoform and monensin A on decreasing acetate / propionate became more evident. This was primarily caused by a transient effect of only bromoform that does not persist in passaged rumen cultures, while the combination of bromoform and monensin A cause a strong decrease at day 2 and 3 of the incubation period (Figure 3).

[0135] References:

[0136] Ahvanooei, MR Rezaei, et al. "Effects of monensin supplementation on rumen fermentation, methane emissions, nitrogen balance, and metabolic responses of dairy cows: A systematic review and dose-response meta-analysis. " Journal of Dairy Science 107.1 (2024): 607-624.

[0137] Garcia-Lopez, P. M., L. Kung Jr, and J. M. Odom. "In vitro inhibition of microbial methane production by 9, 10-anthraquinone." Journal of Animal Science 74.9 (1996): 2276-2284.

[0138] Glasson, Christopher RK, et al. "Benefits and risks of including the bromoform containing seaweed Asparagopsis in feed for the reduction of methane production from ruminants." Algal Research 64 (2022): 102673.

[0139] Newbold, C. James, et al. "Propionate precursors and other metabolic intermediates as possible alternative electron acceptors to methanogenesis in ruminal fermentation in vitro." British Journal of nutrition 94.1 (2005): 27-35.

[0140] Example 2

[0141] An in vivo trial was conducted to compare a treatment of high dose bromoform alone and when combined with fumaric acid and monensin.

[0142] Methods

[0143] Thirty-two Angus steers, with an initial live weight of 250 kg, were individually housed for a period of 70 days. Throughout this entire period, the steers were fed a starter feedlot ration. The study included a 14-day dietary adaptation phase followed by a 56-day experimental period. The treatments, with eight steers per treatment group, were added to the basal feedlot ration. The treatment groups were as follows: Control; Tl, which included bromoform at 100 mg / kg dry matter intake (DMI); and T2, which included bromoform at 100 mg / kg DMI, monensin at 22 mg / kg DMI, and fumaric acid at 2.8 g / kg DMI. Individual intake and refusals were recorded, and the steers were weighed fortnightly prior to feed being given. Methane emissions were measured using the SF6 technique on days 48 to 56. Additionally, rumen fluid was collected on day 50 for volatile fatty acids (VFAs) analysis and microbial profiling.

[0144] Results

[0145] The growth results are shown in Table 1 and Table 2. Table 1 includes the individual results for each animal. Table 2 includes the summary results for each treatment. The recorded parameters include initial weight, final weight, total weight gain, average daily gain (ADG), dry matter intake (DMI), and feed conversion efficiency (FCE). The control group (CONT) showed the highest total weight gain and ADG, while Treatment 1 (TRT 1) had the lowest values. Treatment 2 (TRT 2) showed intermediate values, indicating some recovery in weight gain when fumaric acid and monensin were included. The p values in Table 2 were obtained by ANOVA comparing 3 or more groups with each other. Significantly different groups were given different letters (a,b,c).TABLE 1: GROWTH RESULTSTABLE 2: GROWTH RESULTS SUMMARY

[0146] The dry matter intake (DMI) results are shown in Tables 3 and 4. Table 3 includes the DMI results for each animal. Table 4 includes the DMI results for each week across the different treatment groups. The control group consistently had the highest DMI throughout the weeks. Treatment 1 (TRT 1) and Treatment 2 (TRT 2) had lower DMI values compared to the control group, with TRT 2 showing slightly higher DMI than TRT 1 in the later weeks.TABLE 3: DRY MATTER INTAKE BY WEEKTABLE 4: DRY MATTER INTAKE BY WEEK SUMMARY

[0147] The methane production results are shown in Tables 5 and 6. Table 5 includes the methane production results for each animal. Table 6 includes the methane production results for each week across the different treatment groups. The control group (CONT) had the highest methane production in grams per day, grams per kilogram of body weight, grams per kilogram of ADG, and grams per kilogram of DMI. Both Treatment 1 (TRT 1) and Treatment 2 (TRT 2) showed significant reductions in methane production across all metrics, with TRT 2 showing slightly lower values than TRT 1.TABLE 5: METHANE PRODUCTIONTABLE 6: METHANE PRODUCTION SUMMARY

[0148] The p values in Table 6 were obtained by ANOVA comparing 3 or more groups with each other. Significantly different groups were given different letters (a,b,c).

[0149] The results demonstrate that bromoform treatment caused a reduction in weight gain, which was partially recovered by also including fumaric acid and monensin.

[0150] The present disclosure is useful as it provides methods and compositions for modifying methanogenesis and productivity in ruminants. The co-administering a methanogenesis inhibitor and a productivity modifier provides a synergistic effect on reducing of methane production and reducing theacetate-to-propionate ratio. The fumaric acid and monensin can also help to recover the reduction in weight gain that can be caused by administration of a methanogenesis inhibitor. The methanogenesis inhibitor and a productivity modifier may find use in, for example, medicaments, animal feed and animal feed supplements.

[0151] Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that such prior art forms part of the common general knowledge.

[0152] In some cases, a single embodiment may, for succinctness and / or to assist in understanding the scope of the disclosure, combine multiple features. It is to be understood that in such a case, these multiple features may be provided separately (in separate embodiments), or in any other suitable combination. Alternatively, where separate features are described in separate embodiments, these separate features may be combined into a single embodiment unless otherwise stated or implied. This also applies to the claims which can be recombined in any combination. That is a claim may be amended to include a feature defined in any other claim. Further a phrase referring to "at least one of" or “one or more of:” a list of items refers to any combination of those items, including single members. As an example, "at least one of: a, b, or c" is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c, and "one or more of: a, b, or c" is intended to cover: a, b, c, a-b, a-c, b-c, and a-b-c.

[0153] It will be appreciated by the person skilled in the art that the disclosure is not restricted in its use to the particular application or applications described. Neither is the present disclosure restricted in its preferred embodiment with regard to the particular elements and / or features described or depicted herein. It will be appreciated that the disclosure is not limited to the embodiment or embodiments disclosed, but is capable of numerous rearrangements, modifications and substitutions without departing from the scope as set forth and defined by the following claims.Statements of Invention1. A method of reducing methane production and increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.2. A method of reducing methane production in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesisinhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.3. A method of increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.4. The method of any one of the preceding statements, wherein the methanogenesis inhibitor and the productivity modifier are co-administered simultaneously to the ruminant.5. The method of any one of the preceding statements, wherein the methanogenesis inhibitor and the productivity modifier are formulated together.6. The method of any one of the preceding statements, wherein the methanogenesis inhibitor and the productivity modifier are co-administered within 30 minutes or within 20 minutes or within 10 minutes of the consumption of a meal.7. The method of any one of the preceding statements, wherein the methanogenesis inhibitor and the productivity modifier are co-administered at least every 12, 18, 24, 30, 36, 40 or 48 hours.8. The method of any one of the preceding statements, wherein the methanogenesis inhibitor comprises a plurality of halogenated carbon compounds.9. The method of statement 8, wherein the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform, bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3,3-dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, l,l,3,3-tetrabromopropan-2-ol, tribromomethanol, 1,1,3,3-tetrabromoacetone, 1,3- dichloroacetone, 1 , 1 ,3,3-tetrabromopropan-2-one, 1 , 1 ,3,3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3- chloropropan-2-one, 1 , 1 ,3-tribromopropan-2-one, 1 , 1 ,3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3- en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3- iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1 ,3-dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 - chloropropan-2-one, l,3-dibromopropan-2-one, l,3-dichloropropan-2-one, l-bromo-1,3,3- trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 -bromo-3-chloropropan-2-one, 1 -chloro-3- iodopropan-2-one, 3-bromo-l,l-dichloropropan-2-one, 2,2,2-tribromoacetic acid (ethyl ester), 2,2-dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2,2-dibromoacetic acid (methyl ester), 2-bromo- 2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3- dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid (methyl ester), 3-bromo-2- iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2,2-dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes, a-snyderol, P-snyderol, y-snyderol, halogenated fatty acids, 3-bromo-2-heptanoic acids and 3-bromo-2- nonanoic acids, halogenated oxylipins, chlorinated egregiachloride A, chlorinated egregiachloride B, chlorinated egregiachloride C, chlorinated eiseniachloride A, chlorinated eiseniachloride B, chlorinated eiseniachloride C, iodinated eiseniaiodide A, iodinated eiseniaiodide B, halogenated terpenoids, halogenated diterpenes, halogenated triterpenes, halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan-2-ones or halogenated phenols.10. The method of any one of the preceding statements, wherein the methanogenesis inhibitor comprises bromoform.11. The method of any one of the preceding statements, wherein the ionophore comprises a poly ether ionophorous antibiotic.12. The method of any one of the preceding statements, wherein the ionophore comprises one or more of lasalocid A or monensin A.13. The method of any one of the preceding statements, wherein the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate.14. The method of any one of the preceding statements, wherein the co-administering comprises administering about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI), about 50 to about 150 mg per kg DMI of the methanogenesis inhibitor, about 40 to about 120 mg per kg DMI of the methanogenesis inhibitor or about 40 to about 80mg per kg DMI of the methanogenesis inhibitor.15. The method of any one of the preceding statements, wherein the co-administering comprises administering about 5 to about 150mg per kg DMI or about 10 to about 40mg per kg DMI of the ionophore.16. The method of any one of the preceding statements, wherein the co-administering comprises administering about 0.2 to about 20g per kg DMI or about 1 to about 3mg per kg DMI of the succinate / propionate pathway compound.17. The method of any one of statements 1 to 13, wherein the co- administering provides a rumen concentration of the methanogenesis inhibitor of about 2 to about lOuM or about 4 to about 6uM.18. The method of any one of statements 1 to 13 or 17, wherein the co-administering provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM or about 300 to about 400mM.19. The method of any one of statements 1 to 13 or 17-18, wherein the co-administering provides a rumen concentration of the ionophore of about 0.2 to about 20uM or about 1 to about 3uM.20. The method of any one of statements 1 to 13, wherein a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:100.21. The method of statement 20, wherein a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:50 to about 1:80.22. The method of any one of statements 1 to 13 or 20-21, wherein a molar ratio of the methanogenesis inhibitor to the ionophore is about 20:1 to about 1:1.23. The method of statement 22, wherein a molar ratio of the methanogenesis inhibitor to the ionophore is about 15:1 to about 2:1.24. The method of any one of the preceding statements, wherein the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae.25. The method of statement 24, wherein the ruminant is one or more of mouse-deer, deer, moose, giraffe and okapi, pronghorn, musk deer, cattle, goats, sheep, llama, alpaca, bison, elk, reindeer, yak, camel or antelope.26. A composition for reducing methane production and increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.27. A composition for reducing methane production in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.28. A composition for increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.29. The composition of any one of statements 26 to 28, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compounds.30. The composition of statement 29, wherein the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform, bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3, 3 -dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, l,l,3,3-tetrabromopropan-2-ol, tribromomethanol, 1 ,1 ,3,3-tetrabromoacetone, 1 ,3-dichloroacetone, 1 , 1 ,3,3-tetrabromopropan-2-one,1.1.3.3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3-chloropropan-2-one, 1 ,1 ,3-tribromopropan-2-one,1.1.3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3-en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3-iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1,3- dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 -chloropropan-2-one, 1 ,3-dibromopropan-2-one, 1,3- dichloropropan-2-one, 1 -bromo- 1 ,3,3-trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 - bromo-3-chloropropan-2-one, 1 -chloro-3-iodopropan-2-one, 3-bromo- 1 , 1 -dichloropropan-2-one, 2,2,2- tribromoacetic acid (ethyl ester), 2,2-dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2,2- dibromoacetic acid (methyl ester), 2-bromo-2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2- enoic acid (methyl ester), 3-bromo-2-iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2, 2 -dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes (such as a-snyderol, P-snyderol, and y-snyderol), halogenated fatty acids (such as 3-bromo-2-heptanoic acids and 3-bromo-2-nonanoic acids), halogenated oxylipins (e.g., chlorinated egregiachlorides A, B and C, chlorinated eiseniachlorides A, B and C, and iodinated eiseniaiodides A, B), halogenated terpenoids (e.g., diterpenes and triterpenes), halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan- 2-ones or halogenated phenols.31. The composition of any one of statements 26 to 28, wherein the methanogenesis inhibitor comprises bromoform.32. The composition of any one of statements 26 to 31, wherein the ionophore comprises a polyether ionophorous antibiotic.33. The composition of any one of statements 26 to 32, wherein the ionophore comprises one or more of lasalocid A or monensin A.34. The composition of any one of statements 26 to 33, wherein the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate.35. The composition of any one of statements 26 to 34, wherein a dosage of the composition provides about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI), about 50 to about 150 mg per kg DMI of the methanogenesis inhibitor, about 40 to about 120 mg per kg DMI of the methanogenesis inhibitor or about 40 to about 80mg per kg DMI of the methanogenesis inhibitor.36. The composition of any one of statements 26 to 35, wherein a dosage of the composition provides about 5 to about 150mg per kg DMI or about 10 to about 40mg per kg DMI of the ionophore.37. The composition of any one of statements 26 to 36, wherein a dosage of the composition provides about 0.2 to about 20g per kg DMI or about 1 to about 3mg per kg DMI of the succinate / propionate pathway compound.38. The composition of any one of statements 26 to 34, wherein a dosage of the composition provides a rumen concentration of the methanogenesis inhibitor of about 2 to about lOuM or about 4 to about 6uM.39. The composition of any one of statements 26 to 34 or 38, wherein a dosage of the composition provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM or about 300 to about 400mM.40. The composition of any one of statements 26 to 34 or 38-39, wherein a dosage of the composition provides a rumen concentration of the ionophore of about 0.2 to about 20uM or about 1 to about 3uM.41. The composition of any one of statements 26 to 34, wherein a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:100.42. The composition of any one of statements 26 to 34, wherein a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:50 to about 1:80.43. The composition of any one of statements 26 to 34 or 41-42, wherein a molar ratio of the methanogenesis inhibitor to the ionophore is about 20:1 to about 1:1.44. The composition of any one of statements 26 to 34 or 41-43, wherein a molar ratio of the methanogenesis inhibitor to the ionophore is about 15:1 to about 2:1.45. The composition of any one of statements 26 to 44, wherein the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae.46. The composition of statement 45, wherein the ruminant is one or more of mouse-deer, deer, moose, giraffe and okapi, pronghorn, musk deer, cattle, goats, sheep, llama, alpaca, bison, elk, reindeer, yak, camel or antelope.47. The composition of any one of statements 26 to 46, wherein the methanogenesis inhibitor and the productivity modifier in combination when administered to a ruminant synergistically increase productivity / feed conversion efficiency or decrease methane emissions in said ruminant as compared to an additive effect of administering to a ruminant the methanogenesis inhibitor or the productivity modifier individually.48. A method of increasing productivity in a ruminant, comprising administering a therapeutically effective amount of the composition of any one of statements 26 to 46 to the ruminant.49. The method of statement 48, wherein productivity is measured by one or more of a reduction in methane production, an increase in feed conversion efficiency, an increase in weight gain or a reduction in an acetate-to-propionate ratio.50. A method of decreasing the ratio of acetate to propionate in a ruminant, comprising administering a therapeutically effective amount of the composition of any one of statements 26 to 46 to the ruminant.51. A method of increasing feed conversion efficiency in a ruminant, comprising administering a therapeutically effective amount of the composition of any one of statements 26 to 46 to the ruminant.52. Use of a methanogenesis inhibitor and a productivity modifier for reducing methane production and increasing feed conversion efficiency in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.53. Use of a methanogenesis inhibitor and a productivity modifier for reducing methane production in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carboncompound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.54. Use of a methanogenesis inhibitor and a productivity modifier for increasing feed conversion efficiency in a ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.55. Use of a methanogenesis inhibitor comprising one or more halogenated carbon compound, and a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, in the manufacture of a supplement or feed for reducing methane production and increasing feed conversion efficiency in a ruminant.56. Use of a methanogenesis inhibitor comprising one or more halogenated carbon compound, and a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, in the manufacture of a medicament for reducing methane production and increasing feed conversion efficiency in a ruminant.57. An animal feed supplement, comprising the composition of any one of statements 26 to 46.58. An animal feed, comprising the composition of any one of statements 26 to 46 or the supplement of statement 57.59. A kit comprising first and second containers, wherein the first container contains a methanogenesis inhibitor comprising one or more halogenated carbon compound, and the second container contains a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof; optionally packaged with instructions for the use of the kit in the method of any one of statements 1 to 51.60. A method for managing methane emissions and weight gain in ruminant animals, comprising:(a) administering to the ruminant animal an effective amount of a methanogenesis inhibitor comprising one or more halogenated carbon compound, wherein the administration of the methanogenesis inhibitor results in a reduction in the weight gain of the animal and a reduction in methane emissions from the animal; and(b) co-administering to the ruminant animal an effective amount of a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof, wherein the productivity modifier at least partially recovers the reduction in weight gain caused by themethanogenesis inhibitor, without negating the reduction in methane emissions achieved by the methanogenesis inhibitor.

Claims

CLAIMS1. A method of reducing methane production and increasing feed conversion efficiency in a ruminant, comprising co-administering a methanogenesis inhibitor and a productivity modifier to the ruminant, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

2. A method for managing methane emissions and weight gain in ruminant animals, comprising:(a) administering to the ruminant animal an effective amount of a methanogenesis inhibitor comprising one or more halogenated carbon compound, wherein the administration of the methanogenesis inhibitor results in a reduction in the weight gain of the animal and a reduction in methane emissions from the animal; and(b) co-administering to the ruminant animal an effective amount of a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound or a combination thereof , wherein the productivity modifier at least partially recovers the reduction in weight gain caused by the methanogenesis inhibitor, without substantially negating the reduction in methane emissions achieved by the methanogenesis inhibitor.

3. The method of claim 1 or 2, wherein the methanogenesis inhibitor and the productivity modifier are co-administered simultaneously to the ruminant or are formulated together.

4. The method of any one of the preceding claims, wherein the methanogenesis inhibitor and the productivity modifier are co-administered within 30 minutes or within 20 minutes or within 10 minutes of the consumption of a meal.

5. The method of any one of the preceding claims, wherein the methanogenesis inhibitor and the productivity modifier are co-administered at least every 12, 18, 24, 30, 36, 40 or 48 hours.

6. A composition for reducing methane production and increasing feed conversion efficiency in a ruminant, comprising a methanogenesis inhibitor and a productivity modifier, wherein the methanogenesis inhibitor comprises one or more halogenated carbon compound and wherein the productivity modifier comprises one or more ionophore or succinate / propionate pathway compound or a combination thereof.

7. The method of any one of claims 1-5 or the composition of claim 6, wherein the methanogenesis inhibitor comprises a plurality of halogenated carbon compounds.

8. The method of claim 7 or the composition of claim 7, wherein the plurality of halogenated carbon compounds comprises one or more of 1 -bromo-heptyl bromide, 1 -bromo-hexyl bromide, dibromochloromethane, bromoform, bromochloroacetate, dibromoacetate, bromochlorodimenone, diiodomethane, chloroiodomethane, bromoiodomethane, dibromomethane, methyl iodide, bromochloromethane, bromodichloromethane, dichloromethane, dibromoiodomethane, trichloroacetaldehyde, bromochloroacetic acid, dibromoacetic acid, 3, 3 -dibromoacrylic acid, iodoform, tetrabromomethane, tribromomethane, trichloromethane, tetrachloromethane, 1,1,3,3-tetrabromopropan- 2-ol, tribromomethanol, 1,1,3,3-tetrabromoacetone, 1,3 -dichloroace tone, l,l,3,3-tetrabromopropan-2-one,1.1.3.3-tetrachloropropan-2-one, 1 , 1 ,3-tribromo-3-chloropropan-2-one, 1 ,1 ,3-tribromopropan-2-one,1.1.3-trichloropropan-2-one, 1 , 1 ,4,4-tetrabromobut-3-en-2-one, 1 , 1 -dibromo-3,3-dichloropropan-2-one, 1 , 1 -dibromo-3-chloropropan-2-one, 1 , 1 -dibromo-3-iodopropan-2-one, 1 , 1 -dibromopropan-2-one, 1,3- dibromo- 1 ,3-dichloropropan-2-one, 1 ,3-dibromo- 1 -chloropropan-2-one, 1 ,3-dibromopropan-2-one, 1,3- dichloropropan-2-one, 1 -bromo- 1 ,3,3-trichloropropan-2-one, 1 -bromo- 1 ,3-dichloropropan-2-one, 1 - bromo-3-chloropropan-2-one, 1 -chloro-3-iodopropan-2-one, 3-bromo- 1 , 1 -dichloropropan-2-one, 2,2,2- tribromoacetic acid (ethyl ester), 2,2-dibromoacetic acid, 2,2-dibromoacetic acid (ethyl ester), 2,2- dibromoacetic acid (methyl ester), 2-bromo-2-chloroacetic acid, 2,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2-enoic acid, 3,3-dibromoprop-2-enoic acid (ethyl ester), 3,3-dibromoprop-2- enoic acid (methyl ester), 3-bromo-2-iodoprop-2-enoic acid, 3-bromo-3-chloroprop-2-enoic acid (ethyl ester), 3-bromoprop-2-enoic acid (ethyl ester), 2-bromoacetaldehyde, 2, 2 -dibromoacetaldehyde, bromopyrroles, brominated cyclic sesquiterpenes, a-snyderol, P-snyderol, y-snyderol, halogenated fatty acids, 3-bromo-2-heptanoic acids and 3-bromo-2-nonanoic acids, halogenated oxylipins, chlorinated egregiachloride A, chlorinated egregiachloride B, chlorinated egregiachloride C, chlorinated eiseniachloride A, chlorinated eiseniachloride B, chlorinated eiseniachloride C, iodinated eiseniaiodide A, iodinated eiseniaiodide B, halogenated terpenoids, halogenated diterpenes, halogenated triterpenes, halogenated indoles, halogenated acetogenins, halogenated naphthalenes, halogenated furanones, halogenated heptan-2-ones or halogenated phenols or combinations thereof.

9. The method of any one of claims 1-5, 7 or 8, or the composition of any one of claims 6-8, wherein the methanogenesis inhibitor comprises bromoform.

10. The method of any one of claims 1-5 or 7-9, or the composition of any one of claims 6-9, wherein the ionophore comprises a polyether ionophorous antibiotic.

11. The method of any one of claims 1-5 or 7-10, or the composition of any one of claims 6-10, wherein the ionophore comprises lasalocid A, monensin A or a combination thereof.

12. The method of any one of claims 1-5 or 7-11, or the composition of any one of claims 6-11, wherein the succinate / propionate pathway compound comprises one or more of malate, fumarate, aspartate, lactate, pyruvate, oxaloacetate, succinate or propionate or a combination thereof.

13. The method of any one of claims 1-5 or 7-12, wherein the co-administering comprises administering about 10 to about 200 milligrams per kilogram of dry matter intake (mg per kg DMI) or about 40 to about 120mg per kg DMI of the methanogenesis inhibitor.

14. The method of any one of claims 1-5 or 7-13, wherein the co-administering comprises administering about 5 to about 150mg per kg DMI or about 10 to about 40mg per kg DMI of the ionophore.

15. The method of any one of claims 1-5 or 7-14, wherein the co-administering comprises administering about 0.2 to about 20g per kg DMI or about 1 to about 4mg per kg DMI of the succinate / propionate pathway compound.

16. The method of any one of claims 1-5 or 7-12, wherein the co-administering provides a rumen concentration of the methanogenesis inhibitor of about 2to about lOuM or about 4 to about 6uM.

17. The method of any one of claims 1-5 or 7-12 or 16, wherein the co-administering provides a rumen concentration of the succinate / propionate pathway compound of about 100 to about 600mM or about 300 to about 400mM.

18. The method of any one of claims 1-5 or 7-12 or 16 or 17, wherein the co-administering provides a rumen concentration of the ionophore of about 0.2 to about 20uM or about 1 to about 3uM.

19. The method of any one of claims 1-5 or 7-12 or the composition of any one of claims 6-12, wherein a molar ratio of the methanogenesis inhibitor to the succinate / propionate pathway compound is about 1:20 to about 1:100.

20. The method of any one of claims 1-5, 7-12 or 19 or the composition of any one of claims 6-12 or19, wherein a molar ratio of the methanogenesis inhibitor to the ionophore is about 20:1 to about 1:1.

21. The method of any one of claims 1-5 or 7-20, or the composition of any one of claims 6-12, 19 or20, wherein the ruminant is of the family Tragulidae, Cervidae, Giraffidae, Antilocapridae, Moschidae or Bovidae.

22. An animal feed supplement, comprising the composition of any one of claims 6-12, 19 or 20.

23. An animal feed, comprising the composition of any one of claims 6-12, 19 or 20 or the supplement of claim 22.

24. A kit comprising first and second containers, wherein the first container contains a methanogenesis inhibitor comprising one or more halogenated carbon compound, and the second container contains a productivity modifier comprising one or more ionophore or succinate / propionate pathway compound; optionally packaged with instructions for the use of the kit in the method of any one of claims 1 to 21.

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