Methods for improving growth performance of feedlot cattle

Abstract

An effective amount of rubabegron or a pharmaceutically acceptable salt thereof is administered in an amount of about 3.5 to 22 mg / kg. -1 A method for improving growth performance in feedlot cattle is disclosed in which rubabegron is administered at a dry matter dose of 16 to 2 days for a maximum of 56 days prior to harvest.

Description

[Technical Field]

[0001] The present invention generally relates to a method for improving growth performance in feedlot cattle by administering an effective amount of rubabegron or a pharmaceutically acceptable salt thereof. [Background technology]

[0002] The development of technologies that promote environmental management while maintaining or improving the efficiency of food animal production is essential for the sustainability of food supplies to meet the demands of a growing population. Rubabegron, when administered in feed during the last 14 to 91 days of life, reduces the risk of death by 100%. -1 It was approved by the U.S. Food and Drug Administration in 2018 to reduce NH3 gas emissions per finishing body weight (BW) and hot carcass weight (HCW). There is a need in the art to improve the growth performance of feedlot cattle. Applicant unexpectedly discovered that, in addition to reducing NH3 emissions, certain doses of rubabegron had a positive impact on the growth performance of feedlot cattle, and growth performance was not significantly attenuated even when rubabegron was removed prior to harvest. Summary of the Invention

[0003] The present disclosure provides 3.5 to 22 mg*kg- 1の Dry matter (3.5mg*kg- 1 The present invention relates to a method for improving the growth performance of feedlot cattle, comprising administering to the cattle an effective amount of rubabegron or a physiologically acceptable salt thereof at a dose of about 1.2 g / ton dry matter (equivalent to about 3.2 g / ton dry matter). In one embodiment, rubabegron is administered for a period of 56 to 91 days.

[0004] In an embodiment, the dose is about 3.5 to 5.5 mg*kg -1 is.

[0005] In an embodiment, the dose is 5.5 to 22 mg*kg -1 is.

[0006] In an embodiment, administration is during the last 56 days of the finishing period.

[0007] In an embodiment, rubabegron is removed 2 to 16 days prior to harvest without significantly attenuating improved growth performance.

[0008] In an embodiment, rubabegron is removed for 2 to 16 days prior to harvest, and final body weight (BW), hot carcass weight (HCW), average daily gain (ADG), gain / feed ratio (G:F), dry matter intake (DMI), carcass yield, loin center area or longissimus dorsi muscle area (LM area), yield grade (YG), and / or yield grade distribution are not significantly attenuated by removal of rubabegron.

[0009] In an embodiment, rubabegron is removed for 16 days prior to harvest without significantly attenuating the improved growth performance.

[0010] In an embodiment, administration of rubabegron increases final body weight (BW) by at least 11 kg compared to control cows not administered rubabegron.

[0011] In an embodiment, administration of rubabegron results in an increase in hot carcass weight (HCW) of at least 15 kg compared to control cattle not administered rubabegron.

[0012] In embodiments, administration of rubabegron results in an increase in average daily gain (ADG) of about 11% to 16% compared to control cows not administered rubabegron.

[0013] In embodiments, administration of rubabegron increases the gain / feed ratio (G:F) by at least 10% compared to control cows not administered rubabegron. In embodiments, administration increases dry matter intake (DMI) by the cow by about 2% to 3%.

[0014] In embodiments, administration of rubabegron increases loin eye area compared to control cows not administered rubabegron.

[0015] In embodiments, administration of rubabegron increases carcass yield relative to control cattle not administered rubabegron, hi certain embodiments, carcass yield increases by about 0.9 to 1.3 units.

[0016] In embodiments, administration of rubabegron reduces yield grade (YG) compared to control cows not administered rubabegron. In certain embodiments, YG is reduced by about 10% to 11% compared to control cows not administered rubabegron.

[0017] In embodiments, administration of rubabegron improves yield grade distribution compared to control cows not administered rubabegron. In certain embodiments, a higher percentage of cows are in yield grade 2 compared to control cows not administered rubabegron. In embodiments, a lower percentage of cows are in yield grade 4 compared to control cows not administered rubabegron.

[0018] In an embodiment, rubabegron is administered in the feed.

[0019] In embodiments, rubabegron is administered as rubabegron fumarate.

[0020] In embodiments, the present disclosure provides a method for reducing kidney-pelvic-heart fat (KPH) in feedlot cattle, comprising administering an effective amount of rubabegron or a physiologically suitable salt thereof.

[0021] In one embodiment, the dose of rubabegron administered is about 22 mg*kg to reduce KPH. -1 is.

[0022] Other objects and features will be in part apparent and in part pointed out hereinafter.

[0023] How to improve growth production The present disclosure provides a method for improving growth performance of feedlot cattle by administering an effective amount of rubabegron or a salt thereof.

[0024] Methods for assessing improved production are known in the art, and one of skill in the art will recognize that improved production may be measured by comparing health, weight, size, meat quality, and other parameters between subjects receiving an immunomodulatory composition and subjects not receiving an immunomodulatory composition.

[0025] In some embodiments, rubabegron is administered as rubabegron fumarate.However, because rubabegron contains a basic moiety, it can also exist as pharmaceutical acid addition salts.These salts include salicylate, sulfate, pyrosulfate, bisulfite, sulfite, bisulfite, phosphate, monohydrogenphosphate, dihydrogenphosphate, metaphosphate, pyrophosphate, chloride, bromide, iodide, acetate, propionate, decanoate, caprylate, acrylate, formate, isobutyrate, heptanoate, propiolate, oxalate, malonate, succinate, suberate, sebacate, maleate, 2-butyne-1,4-dioate, 3-hexyne- 2,5-dioate, benzoate, chlorobenzoate, hydroxybenzoate, methoxybenzoate, phthalate, xylenesulfonate, phenylacetate, phenylpropionate, phenylbutyrate, citrate, lactate, hippurate, β-hydroxybutyrate, glycolate, maleate, tartrate, methanesulfonate, propanesulfonate, naphthalene-1-sulfonate, naphthalene-2-sulfonate, mandelate, and similar salts. Preferred acid addition salts include hemifumarate, benzoate, salicylate, R-mandelate, hydrochloride, and glycolate.

[0026] definition Rubabegron has the chemical name 2-{4-[2-({(2S)-2-hydroxy-3-[2-(2-thienyl)phenoxy]propyl}amino)-2-methylpropyl]phenoxy}nicotinonitrile. Rubabegron free base has the CAS number: 391920-32-4.

[0027] The term "effective amount" refers to an amount necessary or sufficient to achieve a desired biological effect. For example, an effective amount of rubabegron is the amount necessary to induce improvements in growth performance in feedlot cattle, as described below.

[0028] The term "induce" can be used interchangeably with the terms activate, stimulate, generate, or upregulate.

[0029] The term "weight" can refer to unshrunken weight or shrunken weight. Shrunkenness is imposed on cattle to remove gastrointestinal contents.

[0030] The term "hot carcass weight" is the weight in pounds of the unchilled carcass after the head, hide, and viscera have been removed.

[0031] The term "finishing period" or "feeding period" refers to the period during which cattle are fed a high energy diet to promote weight gain and muscle production and optimize fat mass prior to slaughter.

[0032] The term "average daily gain" or "ADG" is the average amount of body weight an animal gains each day during the feeding or finishing period. It can be calculated by measuring the animal's weight gain since the last weigh-in and dividing the weight by the number of days since the last weigh-in. In embodiments, the CPE average of the unshrunken initial BW and final BW is used to calculate ADG.

[0033] "Carcass yield" is the percentage of the live animal's body weight that becomes the carcass weight at slaughter. It is calculated by dividing the HCW by the animal's shrunken live weight and expressing the value as a percentage (x 100).

[0034] "Gain / feed ratio" or "G:F" is the ratio of the amount of feed an animal consumes compared to the amount of body weight gained. For example, G:F is calculated as the quotient of ADG divided by dry matter intake (DMI).

[0035] "Loin center area" is the surface area of ​​the longissimus dorsi muscle between the 12th and 13th ribs of a beef or lamb carcass. This is also called the longissimus muscle area or "LA."

[0036] "Marbling score" or "MS" is a visual assessment of the visible fat between the muscle fiber bundles within the loin center muscle.

[0037] As used herein, "feedstock cattle" includes bulls, steers, cows, heifers, and spayed cattle.

[0038] "Yield Grade" or "YG" is an estimate of the amount of trimmed cuts from the higher-value portions of the carcass, i.e., round, loin, rib, and shoulder, that are close to the standard sold at retail. Yield grades are rated numerically and are 1, 2, 3, 4, and 5. Carcasses with a yield grade of 1 are the leanest, while carcasses with a yield grade of 5 are the fattiest. Carcass yield grade is determined by 1) exterior fat, 2) kidney-heart-pelvis fat, 3) loin eye area, and 4) hot carcass weight. Yield grade can be determined using the following formula: 2.50 + (2.5 x adjusted fat thickness in inches) + (0.2 x kidney-pelvis-heart fat percent) + (0.0038 x hot carcass weight) - (0.32 x loin eye area in square inches).

[0039] "Yield grade distribution" is the percentage of cows in a particular yield grade, i.e., 1, 2, 3, 4, or 5, relative to the total number of graded cows. Improved yield grade distribution is achieved when an intervention causes one or more cows in the relevant population to have a lower yield grade than would have been observed without the intervention.

[0040] With respect to improved growth performance due to rubabegron administration, "not significantly attenuated" means that there is no statistically significant change (P<0.05) in improved growth performance, by whatever measure, measured in feedlot cattle that have rubabegron removed 2-16 days prior to harvest compared to that observed and / or expected in feedlot cattle that have not had rubabegron removed 2-16 days prior to harvest.

[0041] When introducing elements of the present invention or preferred embodiments thereof, the articles "a," "an," and "the" are intended to mean that there are one or more elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0042] Administration and Dosage In an embodiment, rubabegron or a physiologically acceptable salt thereof is administered in feed to feedlot cattle.

[0043] An embodiment for administration of rubabegron or a physiologically acceptable salt thereof is via the daily feed, although rubabegron or a physiologically acceptable salt thereof may also be incorporated into salt blocks and mineral licks or added directly to lick tank formulations or drinking water for convenient oral ingestion. Rubabegron or a physiologically acceptable salt thereof may also be administered orally by bolus or gavage.

[0044] In an embodiment, a feed additive is provided comprising rubabegron or a physiologically acceptable salt thereof and one or more suitable carriers. The feed additive may be a dry feed additive or a liquid feed additive. The feed additive is formulated so that, when added with other minerals, it forms an animal feed that provides a desired concentration of rubabegron or a physiologically acceptable salt thereof in the animal feed, and / or the animal feed intake provides a desired dose of rubabegron or a physiologically acceptable salt thereof for the cattle. For certain feed additives, the term "premix" is widely accepted in the art. Premixes may be solid or liquid. Mineral premixes are compositions for animal feed formulation that contain desired types and amounts of minerals, particularly trace elements. Vitamin premixes are compositions for animal feed formulation that contain desired types and amounts of vitamins. Some premixes contain both vitamins and minerals. Thus, feed additives contain premixes, such as mineral premixes, vitamin premixes, and premixes containing both vitamins and minerals.

[0045] In embodiments, rubabegron or a physiologically acceptable salt thereof is orally administered to a cow for a suitable period of time, for example, one day or more. In embodiments, the administration period may be any number of days between 1 and 100 days. For example, the administration period may be at least 1 day, at least 10 days, at least 20 days, at least 30 days, at least 40 days, at least 50 days, at least 60 days, at least 70 days, at least 80 days, at least 90 days, or at least 100 days. In embodiments, rubabegron or a physiologically acceptable salt thereof is administered for at least 91 days. In some embodiments, rubabegron or a physiologically acceptable salt thereof is administered for at least 56 days. In embodiments, rubabegron or a physiologically acceptable salt thereof is administered for any period between 56 and 91 days, including 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 days.

[0046] In some embodiments, the administration period ends with the slaughter of the cattle. The administration period may be, for example, within the last 10, 20, 30, 40, 50, 60, 70, 80, 90, or 100 days immediately prior to slaughter. In some embodiments, the administration period may be a 56-day or 91-day period immediately prior to slaughter. In some embodiments, rubabegron or a physiologically acceptable salt thereof is administered during any period between the last 56 and 91 days prior to slaughter, including the last 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 days. In other embodiments, orally administered rubabegron or a physiologically acceptable salt thereof is discontinued or removed one or more days prior to slaughter, for example, rubabegron may be removed between 2 and 16 days prior to slaughter.

[0047] In an embodiment, rubabegron or a physiologically acceptable salt thereof is administered at a dose of about 1.5 to 22 mg / kg -1is administered at a dose that provides a dry matter content of 1000 mg / kg.

[0048] In an embodiment, rubabegron or a physiologically acceptable salt thereof is administered at a dose of about 3.5 to 5.5 mg / kg -1 is administered at a dose that provides a dry matter content of 1000 mg / kg.

[0049] The dosage of rubabegron may alternatively be expressed in grams per tonne of dry matter. Grams per tonne of dry matter is approximately 1.102 mg*kg of dry matter. -1 Thus, in embodiments, the physiologically acceptable salt of rubabegron is generally administered at about 1.36 to 19.96 grams / ton of feed, about 3.18 to 19.96 grams / ton of feed, or about 4.99 to 19.96 grams / ton of feed.

[0050] Delivery systems may also include non-polymeric systems, such as lipids containing sterols such as cholesterol, cholesterol esters, and fatty acids, or neutral fats such as monoglycerides, diglycerides, and triglycerides, hydrogel release systems, silastic systems, peptide-based systems, wax coatings, compressed tablets using conventional binders and excipients, partially fused implants, etc. Specific examples include, but are not limited to, erosion systems in which the agent of the present invention is contained within a matrix, such as those described in U.S. Patent Nos. 4,452,775, 4,675,189, and 5,736,152, and diffusion systems in which the active ingredient permeates through a polymer at a controlled rate, such as those described in U.S. Patent Nos. 3,854,480, 5,133,974, and 5,407,686. In addition, pump-based hardware delivery systems can be used, some of which are adapted for implantation.

[0051] Rubabegron or a pharmaceutically acceptable salt thereof may be administered with other vitamins, minerals, and medications as needed. In an embodiment, rubabegron is administered with monensin and tylosin.

[0052] In embodiments, rubabegron or a physiologically acceptable salt thereof is administered during the finishing period.

[0053] In embodiments, rubabegron or a physiologically acceptable salt thereof is administered during the last 91 days of the finishing period.

[0054] In one embodiment, rubabegron or a physiologically acceptable salt thereof is administered during the last 56 days of the finishing period.

[0055] In embodiments, rubabegron or a physiologically acceptable salt thereof is administered for any period between the last 56 and 91 days of the finishing period, including the last 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, or 90 days.

[0056] In an embodiment, rubabegron is removed from the feed for a period of, for example, 2 to 16 days prior to harvest without significantly attenuating positive growth performance.

[0057] In embodiments, rubabegron is removed from the diet, e.g., for a period of 2 to 16 days prior to harvest, without significantly diminishing positive growth performance in terms of finishing body weight (BW), hot carcass weight (HCW), average daily gain (ADG), gain / feed ratio (G:F), dry matter intake (DMI), carcass yield, loin eye area or longissimus dorsi area (LM area), yield grade (YG), and / or yield grade distribution.

[0058] In embodiments, rubabegron is removed 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, or 16 days prior to harvest.

[0059] In embodiments, rubabegron is removed 2 days, 4 days, 6 days, 8 days, or 16 days prior to harvest.

[0060] In one embodiment, the rubabegron is removed 16 days prior to harvest.

[0061] Evaluation of growth performance Developmental performance following administration of rubabegron or a physiologically acceptable salt thereof can be measured using methods and assays known to those skilled in the art, including the methods used in the Examples below.

[0062] In embodiments, administration of rubabegron or a physiologically acceptable salt thereof improves or increases one or more of: final body weight (BW), hot carcass weight (HCW), average daily gain (ADG), gain / feed ratio (G:F), dry matter intake (DMI), carcass yield, loin eye area or longissimus dorsi area (LM area), yield grade (YG), and / or yield grade distribution.

[0063] In embodiments, administration of rubabegron or a physiologically acceptable salt thereof reduces kidney-pelvis-cardiac fat (KPH). DETAILED DESCRIPTION OF THE INVENTION

[0064] The following paragraphs describe exemplary embodiments of the present disclosure.

[0065] 1. A method for improving the growth performance of feedlot cattle, comprising administering to cattle an effective amount of rubabegron or a physiologically acceptable salt thereof at a dose of 3.5 to 22 mg*kg-1 dry matter.

[0066] 2. Rubabegron or its physiologically acceptable salts at a dose of 5.5 mg / kg -1 2. The method of embodiment 1, wherein the medicament is administered in a dry matter dose of

[0067] 3. The method of embodiment 1 or 2, wherein the administration is for 56 to 91 days.

[0068] 4. The method of embodiment 3, wherein the administration is during the last 56 to 91 days of the finishing period.

[0069] 5. The method of any one of embodiments 1 to 3, wherein rubabegron is removed for 2 to 16 days before harvest, and positive growth performance is not significantly attenuated by removal of rubabegron.

[0070] 6. The method of any one of embodiments 1 to 3, wherein rubabegron is removed for 2 to 16 days before harvest, and wherein final body weight (BW), hot carcass weight (HCW), average daily gain (ADG), gain / feed ratio (G:F), dry matter intake (DMI), carcass yield, loin eye area or longissimus dorsi area (LM area), yield grade (YG), and / or yield grade distribution are not significantly attenuated by the removal of rubabegron.

[0071] 7. The method of embodiment 5 or 6, wherein rubabegron is removed 16 days before harvest.

[0072] 8. The method of any one of embodiments 1-7, wherein the administration results in an increase in final body weight (BW) of at least 11 kg compared to control cattle not administered rubabegron.

[0073] 9. The method of any one of embodiments 1-8, wherein the administration results in an increase in hot carcass weight (HCW) of at least 15 kg compared to control cattle not administered rubabegron.

[0074] 10. The method of any one of embodiments 1-7, wherein the administration results in an increase in average daily gain (ADG) of about 11% to 16% compared to control cattle not administered rubabegron.

[0075] 11. The method of any one of embodiments 1-7, wherein the administration increases the gain / feed ratio (G:F) by at least 10% compared to control cattle not administered rubabegron.

[0076] 12. The method of any one of embodiments 1-7, wherein the administration increases the dry matter intake (DMI) by the cow by about 2% to 3% compared to control cows not administered rubabegron.

[0077] 13. The method of any one of embodiments 1-7, wherein the administration increases loin eye area compared to control cows not administered rubabegron.

[0078] 14. The method of any one of embodiments 1-7, wherein the administration increases carcass yield compared to control cattle not administered rubabegron.

[0079] 15. The method of embodiment 14, wherein carcass yield is increased by about 0.9 to 1.3 units.

[0080] 16. The method of any one of embodiments 1-7, wherein the administration reduces yield grade (YG) compared to control cows not administered rubabegron.

[0081] 17. The method of embodiment 16, wherein YG is reduced by about 10% to 11% compared to control cows not administered rubabegron.

[0082] 18. The method of any one of embodiments 1-7, wherein the administration improves yield grade distribution compared to control cows not administered rubabegron.

[0083] 19. The method of embodiment 18, wherein a higher percentage of the cows are in yield grade 2 compared to control cows not administered rubabegron.

[0084] 20. The method of embodiment 18, wherein a lower percentage of the cows are in yield grade 4 compared to control cows not administered rubabegron.

[0085] 21. The method of any one of embodiments 1-20, wherein the physiologically acceptable salt is rubabegron fumarate.

[0086] 22. The method according to any one of embodiments 1-21, wherein rubabegron or a physiologically acceptable salt thereof is administered in feed.

[0087] 23. A method for reducing kidney, pelvis, and heart fat (KPH) in feedlot cattle, comprising administering to the cattle an effective amount of rubabegron or a physiologically acceptable salt thereof.

[0088] 24. Rubabegron or its physiologically acceptable salt is administered at a dose of 22 mg / kg. -1 24. The method of embodiment 23, wherein the patient is administered at a dose of

[0089] 25. The method of embodiment 23 or 24, wherein the physiologically acceptable salt is rubabegron fumarate.

[0090] It is intended that all matters contained in the above description and in the examples set forth below be interpreted as illustrative and not in a limiting sense, as various changes can be made in the disclosed compositions, products, and methods without departing from the scope of the invention.

[0091] The following non-limiting examples are provided to further illustrate the present invention. [Example]

[0092] Example 1: 91-day study of rubabegron on growth performance Experimental design and treatments A randomized complete block design was used to evaluate the effect of rubabegron (LUB) on growth performance over a 91-day period using 336 beef cattle (BW = 453 ± 34.5 kg) housed in a cow pen (CPE). The doses were 0.0 (control or CON), 1.38, 5.5, and 22.0 (mg·kg of DM). -1LUB treatments were included in the study based on four doses of 100mg LUB. Due to the limited number of CPEs (n = 8), three consecutive cycles (blocks) were required to generate six replicates for each dose × sex combination. In this way, 112 cattle (56 steers and 56 heifers) were housed simultaneously within each cycle across eight CPEs (14 cattle / CPE), with each dose × sex combination represented by a single CPE / cycle. To ensure that different cattle body sizes were represented, cattle in cycles 1 and 3 were large-sized Continental crossbreds, while cattle in cycle 2 were medium-sized English crossbreds.

[0093] Three treatment cycles were administered from April to July 2014, August to November 2014, and December to March 2015, respectively. Four weeks before the start of treatment for each cycle (day -28), up to 145 cows were procured from a common source, transported to the University of California, Davis, study facility, and group-housed in outdoor pens by sex. The presence of growth-promoting implants was assessed, and existing implants were removed prior to shipment to the study facility to ensure they remained implant-free for at least 28 days before the start of treatment on day 0. No additional implants were administered to these cows, and they were considered unimplanted.

[0094] On day -8, cows were screened by a veterinarian for abnormal health conditions and ranked by BW to identify 56 suitable cows providing the narrowest weight range within each sex. The following day (day -7), the 56 cows selected for study enrollment within each sex were grouped into sets of four cows ranked consecutively by BW. Cows were then randomly assigned to treatments within each weight group and transported to the CPE. CPE was randomly assigned to sex and dose treatment before each cycle, and all study staff were blinded to treatments throughout the study. All cows were fed a negative control basal fattening ration (Table 1) for one week (day -7 to day -1) after being housed in the CPE to allow for acclimation before treatment initiation.

[0095] Treatments began on day 0, and cows in each CPE received their respective treatment for 91 days. Shedding measurements began at 0800 hours on day 0 and ended at 0500 hours on day 91, immediately prior to final BW measurement and removal of cows from the CPE for transport to commercial slaughter. [Table 1]

[0096] cowshed The CPEs were dome-shaped, east-to-west oriented, 22.0 x 11.3 m structures, 6 m high at their highest point, constructed of a steel frame, welded truss arches with parallel steel tubes, and continuous structural webbing (11 m Legend Series Cover-All Building, Saskatoon, Saskatchewan, Canada), and covered with a double-stack Dura-Weave cover (Intertape Polymer Group, Montreal, Quebec, Canada). Each CPE was 185 m 2 The CPE consisted of a 9.1 m linear feed trough space on a concrete apron with a 3% slope from the trough to the west of the pen, and contained a float-activated automatic waterer. Two hinged feed trough flaps were used to facilitate feed delivery, and each CPE had two doors: one large roll-up door for loading and unloading cows into the CPE, and one smaller door for test personnel to access the CPE. Both the doors and trough flaps remained closed when not in use to prevent disruption of the CPE gas equilibrium.

[0097] Before each test cycle began, the CPE was thoroughly cleaned by allowing the existing manure to air dry for 24–48 hours and then removing the manure with a skid loader and power washer. The stall floor was leveled and fully saturated with water to allow for volatilization of existing NH3 from the soil. After a 24-hour volatilization period, new soil was applied and then compacted with a weight roller to create a firm stall surface. Manure accumulation began on day -7, when cows were assigned to the CPE, and remained uninterrupted throughout the 91-day gas emission measurement period for each cycle.

[0098] Air flow and gas measurements at the CPE Each CPE was equipped with a 4.9 x 1.2 m cooling pad on the east side for evaporative cooling of the incoming ambient air and two ventilation fans on the west side to generate directional airflow and negative pressure within the CPE. Flow rates were determined independently for all 16 ventilation fans before and after each cycle using a customized, purpose-built anemometer, and the sum of the two fans within the CPE determined the total outflow for each CPE. Fan efficiency decay curves were created to determine the airflow at any given time using two flow rates obtained at the beginning and end of the cycle. Fan speed was continuously monitored using two sensors (Monarch Instruments, Amherst, NJ, USA), and the static pressure differential between the inside and outside air was monitored to ensure adequate ventilation. Temperature (T) and relative humidity (RH) within the CPE were monitored every 15 seconds during the emission sampling period (Table 2) using an RH / T sensor (Dwyer Instruments, Inc., Michigan City, Indiana, USA), and the same measurements were continuously obtained from the ambient air using an on-site weather station (Novalynx, Model 110-WS-16, Auburn, California). [Table 2]

[0099] Health observation Cows were observed daily by trained personnel, and any abnormal health observations were recorded. Observed health conditions that disqualified animals and potentially required removal later in the study were documented to prevent considering affected cows for study enrollment. Veterinarians conducted additional observations as the cows progressed through the sales channel, including during loading onto the semi-trailer, during unloading at the slaughterhouse, and finally as pre-slaughter observations after a minimum of 5 hours in the livestock staging area. All cows that were euthanized or found dead were necropsied by a veterinarian. During the treatment period, six cows were found dead, and four others were excluded from the study due to various conditions.

[0100] Dietary formulation and feed assays Cows were fed a concentrate-based diet in a commercial environment before arriving at the study facility on day -28, at which point they were provided with free access to water and readapted to the concentrate-based diet using a gradual program that included increasing levels of concentrate (approximately 60% and 70%, respectively) and two intermediate diets based on various percentages of alfalfa and wheat hay. On day -14, cows were transitioned to a feeder ration (Table 1) formulated to meet or exceed the minimum nutrient requirements for fattening beef cattle (NRC, 2000) and then fed for the remainder of the study. A non-medicated supplement (i.e., Type B ration with a ground corn carrier) was included as 2.5% of the dietary DM during acclimation for all cows from day -14 until the start of treatment administration. On day 0, one of four Type B supplements was added to the basal diet to provide a medicated diet of Type C (i.e., finishing ration) at 0.0 (CON), 1.38 mg kg (CON), or 1.38 mg kg (FINAL ration). -1 , 5.5 mg kg -1 , or 22.0 mg kg -1 All Type C diets containing the appropriate concentrations of LUB or CON were prepared at the study facility by adding equal proportions of Type B supplement, water, and the daily basal diet in a rotary mixer wagon (Roto-Mix Forage Express, Dodge City, Kansas). The mixer procedure (i.e., LUB potency, homogeneity) was verified (i.e., CV ≤ 15%) before the start of the study. Concomitant feed additives (ionophores, antibiotics, antiestrus agents, and β-agonists) were not used at any time during the study. The mixer wagon was cleaned between treatments using a wash load consisting of straw and water. Cleaning was also verified to ensure no LUB carryover between batches. A digital scale on the mixer wagon measured feed delivery with a resolution of 0.45 kg. The scale was verified using a certified check weight before each day's use.

[0101] Target nutrient densities (% of DM) for CP (13.5%), Ca (0.7%), and P (0.3%) were set based on the recommendations of feedlot nutritionists reported in a study by Vasconcelos and Galyean (2007). Three samples were collected daily for each batch of complete ration during delivery from the mixer wagon to the feed trough and frozen until analysis. Three of the seven composite samples representing one week were randomly selected for each treatment and combined and subsampled for weekly analysis of nutrient content [AOAC Methods 985.01 (Ca and P) and 990.03 (CP; Minnesota Valley Testing Laboratories, New Ulm, MN] and LUB concentration (Covance Laboratories, Inc., Greenfield, IN). Minimum acceptable assay values ​​for Ca (0.3%) and P (0.2%) were set at the NRC minimum nutrient requirements for fattening steers (NRC, 2000), while the minimum acceptable value for CP was set at 12.5%. The CP threshold was chosen because it was the minimum level recommended by feedlot nutritionists (Vasconcelos and Galyean, 2007). No samples were below the assay threshold for CP, Ca, or P.

[0102] The LUB concentration was 1.38 mg kg according to FDA guidance ( FDA, 2012 ). -1 and 5.5 mg kg -1 The sample was within ±25% of the target, 20 mg kg -1 The mean LUB potency values ​​for each weekly composite sample across all three test cycles were required to be within ±20% for each dose level (results not shown). Finally, feed samples from CON were assayed for LUB to confirm that the mixer wagon cleaning procedure prevented LUB from being fed and that levels were below the level of quantitation (LOQ = 0.2 g / ton) for each sample assayed.

[0103] Feeding and growth performance Individual BW measurements (uncontracted) were obtained before feeding using a certified weighing scale with a resolution of 0.45 kg on days -8 (randomization), 0 (initial BW), 7, 14, 28, 56, and 91 (final BW). Additionally, weighing scales were validated with check weights before use. Feed troughs were assessed daily for each CPE by trained personnel, who estimated litter from the previous day and determined the amount to be provided in a single delivery to ensure free access to feed. On day 91, remaining litter was weighed to adjust for rejected feed. DMI (kg·animal) was calculated by subtracting the amount of rejected feed from the total feed delivered and then dividing by the cumulative cow-days during the CPE. -1 ·d -1 ) was calculated to determine the amount consumed in kind and then multiplied by the diet DM. Therefore, to comply with the food approval granted by the FDA (FDA, 2016), cattle were removed from the treatment diet at least 24 hours prior to slaughter. The CPE average of unshrunken initial BW and final BW was used to calculate ADG over the 91-day period, and G:F was calculated as the quotient of ADG divided by DMI.

[0104] Slaughter, carcass measurements, and meat quality On day 91, cattle were loaded onto double-decker aluminum semi-trailers and transported approximately 1,000 km to a commercial slaughterhouse. After approximately 5-9 hours in the livestock lair, they were slaughtered. Carcass identity was maintained throughout the slaughter process by recording the sequence of ear tags at the time of stunning, which were then verified against sequentially numbered carcass tags. Hot carcass weight and KPH were measured according to industry-standard processing, and yield grade (YG) and meat quality grade data were collected from the left carcass by trained university personnel after 22 hours in the spray-chilling system.

[0105] After chilling, strip loins (LM) were collected from three randomly selected cows / CPEs and shipped to the Illinois Meat Science Laboratory for Warner-Bratzler shear force (WBSF) determination. In the laboratory, the front end of the strip loin was prepared into 2.54 cm steaks, vacuum-packed, and aged at 4°C until 14 days postmortem. After aging, the steaks were frozen and then thawed at 4°C for 24 hours before being cooked in a Farberware Open Hearth electric broiler (Farberware, Bronx, NY). Internal temperature was monitored using a copper-constant type-T thermocouple (Omega Engineering, Stamford, CT, USA) connected to a digital scanning thermometer (Barnant Co., Barrington, IL), and each steak was flipped when the internal temperature reached 35°C. When a temperature of 70°C was achieved, the steaks were removed from the grill and allowed to cool to approximately 25°C before six cores (1.25 cm diameter) were removed parallel to the muscle fiber orientation. Using a Texture analyzer TA.HD Plus (Stable Microsystems, Godalming, UK) equipped with a WBSF attachment, the cores were sheared perpendicular to the muscle fibers, and the peak WBSF measurements were averaged across all six cores to obtain a single shear force measurement (kg of force) for each steak.

[0106] statistical analysis Data were analyzed using SAS (SAS Institute, Cary, NC) version 9.2, with each individual CPE considered as an experimental unit. Continuous variables were analyzed using PROC MIXED, with treatment (LUB dose), sex, and the dose × sex interaction as fixed effects, and cycle included in the model as a random effect. If the dose × sex interaction was not significant (P > 0.05), the main effect of dose pooled across sexes was assessed. When the main effect of dose was significant (P ≤ 0.05) or tending to be significant (0.05 ≤ P ≤ 0.10), planned contrasts were conducted pairwise comparing each LUB dose to CON. If dose × sex was significant (P ≤ 0.05), planned contrasts were conducted pairwise comparing each LUB dose to CON within sex. Treatment means were estimated using the LSMEANS statement.

[0107] Prior to study implementation, the CVM concluded that for each claim variable (gassing per unit of BW or HCW), the dose range for each variable would include doses significantly different from CON. Furthermore, a methodology for determining the minimum and maximum effective doses was agreed upon. The minimum effective dose for a claim variable was determined to be the lowest dose used in the study that differed from CON based on planned contrasts conducted after a significant F-test (P < 0.05). To determine the lowest maximum effective dose, a dose-response curve was fitted to the least-squares mean of the doses. If the dose-response curve was determined to be a linear plateau model (Anderson and Nelson, 1975) and the slope was different from zero (P ≤ 0.05), the maximum effective dose was the "junction point" where the plateau began. The junction point was identified by evaluating five specific and competing linear and linear-plateau models based on the minimum P value that indicated the best fit: (i) linear = 0–22.0 mg kg-1; -1 DM to linear, (ii) Quadratic1 = 0–1.38 mg kg−1 DM, 1.38–22.0 mg kg -1 DM to plateau, (iii) Quadratic2 = 0–5.5 mg kg -1DM to linear, 5.5–22.0 mg kg -1 DM to plateau, (iv) Quadratic3 = 0–1.38 mg kg -1 No response in DM, but 1.38–5.5 mg kg -1 to linear, 5.5–22.0 mg kg -1 DM to plateau, (v) Quadratic4 = 0–1.38 mg kg -1 No response and 1.38 to 22.0 mg kg -1 Linear from DM.

[0108] Discrete variables were analyzed using generalized linear mixed models with a binomial distribution and logarithmic link function in PROC GLIMMIX. Classification of fixed and random effects, as well as handling of interactions and pairwise comparisons, were performed in a similar manner to continuous variables. Statistical analysis of YG data was performed on both continuous and discrete forms (e.g., YG 1 = 1.00–1.99, YG 2 = 2.00–2.99). Meat quality grades were further classified into five categories (US Prime, Top 2 / 3 Choice, Low Choice, Select, and Standard) routinely used to determine premium or discount adjustments when cattle are marketed on grid-based systems. Because the model did not converge due to the paucity of data on mortality, YG 4, and Select and Prime meat quality grades, Fisher's exact test was performed using PROC FBMS to evaluate the frequency distribution of CON cattle compared to LUB. Statistical significance of the main effect of dose was determined by P ≤ 0.05, and a trend was declared when 0.05 ≤ P ≤ 0.10.

[0109] result No interaction between dose and sex was observed for any variable measured in the study (P≥0.063).

[0110] Growth performance and carcass characteristics Initial BW did not differ between LUB treatments (P = 0.937) and there was no effect of LUB on DMI (P = 0.585) (Table 6). Compared with cows fed CON, G:F was 1.38 mg kg -1 , 5.5 mg kg -1 , and 22.0 mg kg -1 The effect of LUB treatment on G:F was reflected by a trend (P = 0.075) to improve ADG, which was 1.38 mg kg compared with CON. -1 , 5.5 mg kg -1 , and 22.0 mg kg -1 increased by 11.8%, 9.4%, and 12.6%, respectively, in cows fed LUB, but final BW was unchanged by LUB treatment (P=0.257).

[0111] Compared with CON cows, LUB-fed cows were approximately 15 kg heavier (P ≤ 0.035), had 0.9 to 1.3 units greater carcass yield (P ≤ 0.006), and had LM areas 6.4 to 8.4 cm 2 Compared to carcasses from CON cows, KPH provided 22.0 mg kg 2 carcass weights. - It was reduced (P = 0.001) only when fed LUB 1 (1.96% vs. 1.61%, Table 3). LUB treatment had no effect on calculated YG (P = 0.155). When YG was analyzed as a discrete variable, the probability of cows producing YG3 carcasses was greater in CON than LUB-fed cows (P < 0.019), and the probability of cows producing YG1, YG2, or YG4 carcasses was similar between treatments (P ≥ 0.233).

[0112] LUB treatment had no effect on skeletal, lean, or overall maturity (P ≥ 0.262). Marbling scores tended to be affected by LUB treatment on carcasses from LUB-fed cattle (P = 0.058), with LUB-fed cattle having marbling scores 50 to 63 points lower than CON carcasses (P ≤ 0.051) (Table 3). Feeding LUB shifted the meat quality grade distribution downward, such that LUB-fed cattle were less likely to be graded as a higher Choice grade (P = 0.004) and more likely to be graded as a lower Choice grade (P = 0.021) than CON. The incidence of dark cutters was not affected by treatment, as only a single carcass fell within this category throughout the study. WBSF was 0.27 to 0.44 kg greater in strip loins from LUB-treated cattle than in CON cattle (P ≤ 0.039) (Table 3). [Table 3]

[0113] Gender influence Steers began the treatment period at a weight 43 kg heavier (P < 0.001) than heifers. Over the 91-day period, steers consumed 0.5 kg / day more DM (P = 0.038) than heifers. Both sexes gained weight similarly (P = 0.875), but heifers tended to have a 5% greater G:F (P = 0.064) than steers (Table 4). Heifers produced carcasses 30 kg lighter (P < 0.001) than steers, with adjusted fat thickness 1.17 cm greater (P = 0.024) and KPH 0.45% greater (P < 0.001). LM area and calculated YG did not differ between steers and heifers (P > 0.216). Lean maturity was not affected by sex (P > 0.854), although heifers had slightly higher skeletal maturity (A75 vs. A67) than steers (P < 0.001). Marbling score and WBSF did not differ (P > 0.142), and for each LUB treatment, the increase in HCW was greater for the 15, 16, and 16 kg animals. -1 The theoretical efficiency of N conservation was 1.4 mg kg -1DM LUB, 5.5 mg kg -1 DM LUB, and 22 mg kg -1 and 69.9%, 55.7%, and 49.9% for DM LUB, respectively. [Table 4]

[0114] In addition to the increase in carcass weight mentioned above, assessment of other carcass characteristics provided further information regarding the physiological effects of LUB. Periodic measurements of carcass fat showed no change in adjusted fat thickness, but a decrease in KPH at only the highest LUB dose, and a decrease in marbling score at all doses of LUB. In this study, cows receiving LUB had a 7%-10% increase in LM area and a corresponding 8%-10% decrease in marbling score.

[0115] Cows receiving LUB for 91 days produced LM steaks with average 14-d WBSF values ​​0.27–0.44 kg higher than CON. While limited comparative data are available on fat shear force from LUB-fed cattle, the increased shear force is not unexpected, as similar effects have been reported for other biotechnologies that alter muscle development (Garmen and Miller, 2014). Despite the increased WBSF, the average shear force values ​​for LUB-treated cattle in this study (2.75–2.92 kg) were within the range of recent North American studies reporting WBSF for top loin steaks (approximately 2.0–3.4 kg; Guelker et al., 2013; Howard et al., 2013; Igo et al., 2015; Martinez et al., 2017). The impact of changes in shear force on consumer acceptability has been reported to vary depending on where it occurs within the WBSF observation range (Platter et al., 2003); therefore, additional evaluation of shear force on LUB-fed cattle would further our understanding of this effect. While the present study measured shear force at a single postmortem aging period of 14 days, the most recent National Beef Tenderness Survey (Martinez et al., 2017) reported that post-production aging times for boneless strip loins or top loins were 27.2 days in retail settings and 34.6 days in foodservice settings (Martinez et al., 2017).

[0116] Example 2: Effect of various doses of rubabegron on growth performance and carcass characteristics of steers during the last 56 days of the feeding period. This example examines the effect of LUB doses (0, 1.5, 3.5, and 5.5 mg kg ) on live weight, carcass weight, and related ratios of feedlot cattle during the last 56 days of the feeding period. -1 A randomized complete block study was described in which carcass characteristics, mobility, and health were evaluated. All cows received monensin and tylosin throughout the study.

[0117] This study was conducted at Cactus Research (Amarillo, TX, USA). Animal care and disposal procedures complied with applicable federal, state, and local regulations. All study procedures were reviewed and approved by Elanco's Institutional Animal Care and Use Committee (IACUC, approval number EIAC-0827).

[0118] Experimental design and treatments A randomized complete block design was used to evaluate the effect of LUB on calculated growth performance of 2,880 British crossbred and Continental European crossbred steers representative of US feedlot cattle. Crossbreeding with Zebu was limited to less than 1 / 8. The study included four LUB doses: 0 (control, CON) mg kg -1 DM, 1.5 mg kg -1 DM, 3.5 mg kg -1 DM, and 5.5 mg kg -1 DM was assessed in 12 blocks, each containing four replicate pens where LUB feeding was initiated on the same day. Steers were randomized within each block of four pens with 60 steers per pen, for a total of 720 steers enrolled in each treatment. LUB feeding was initiated on June 24, 2018, July 1, 2018, and July 15, 2018, with four blocks per day.

[0119] Study Timeline and Treatment Allocation On or before day -85 (i.e., 85 days before slaughter) and before randomization, animals eligible for enrollment were selected based on BW, feed date, phenotype, health, and general disposition to select approximately 1,000 steers for potential enrollment in each time-replicate group. Animals were examined by qualified evaluators and screened for eligibility based on the following inclusion criteria. Steers were confirmed as steers and judged to be in good health. Steers received Revalor XS implants (trenbolone acetate and estradiol; Merck Animal Health, Summit, NJ) 4.7–7.0 months before slaughter (i.e., day 0). Animals with pre-existing or previously existing abnormal health conditions or observations were eligible for inclusion in the study if the condition was deemed mild in nature (e.g., mild lacerations, eye redness, dermatitis, etc.) and was not expected to adversely affect or impact the animals' normal growth and ability to complete the study. Blind, ill, or injured animals were excluded. Additionally, animals were excluded due to extreme BW.

[0120] Randomization of animals to pens occurred 66–69 days prior to slaughter, which was considered the start of the approximately 10–15-day acclimation phase. The mean BW for the 12 blocks ranged from 538.4 to 570.6 kg. The minimum and maximum within-block BW ranges across all 12 blocks were 106.1 kg and 118.8 kg, respectively. These data suggest that cattle were uniform across and within blocks to ensure acceptable uniformity at harvest (slaughter). During each randomization event, cattle were assigned to one of four blocks (i.e., time replicates, n = 3). For each replicate, there were four blocks of four pens (one pen for each dose level). Animals were assigned to pens 9–12 days prior to the first feeding of the experimental diets. The experimental diets were fed for 56 days. Complete blocks (four pens, one pen per treatment group) were assigned on a given day. Pens contained 60 steers each and were adjacent. The randomization schedule was prepared using a Microsoft Excel spreadsheet. At randomization, steers were weighed individually and assigned to a test pen if they were within a target weight range of ±56.7 kg. Each subsequent group of four candidate steers was placed into one of the four pens within the block using the randomization schedule. Subsequent blocks were entered by repeating the same procedure. A separate randomization schedule was used to assign one of the four treatments to each of the four pens in each block.

[0121] Health observation During the approximately 10–15 day acclimation phase and throughout the treatment phase until the cattle were loaded for slaughter, all animals were observed by trained caretakers at least once daily; health problems were recorded only in exceptional cases. All abnormalities were recorded, even if they were considered typical for feedlot cattle. Abnormal health observations were those that the observer deemed 1) typical for a feedlot cattle breed for its age, 2) did not cause undue pain or distress to the animal, and / or 3) would not impair the animal's growth at the time the observation was made. Animals with abnormal health observations were allowed to remain in the study. Animals could receive concomitant therapy (e.g., antibiotic treatment for respiratory disease and treatment for bloat). Health observations requiring classification of an animal as "removed" were those that the observer considered 1) to be causing pain or distress to the animal, 2) likely to result in further deterioration of the animal's health, and / or 3) impair the animal's ability to access food or water at the time of observation. Animals removed from the study during the treatment or withdrawal phase were penned separately in the study facility's feedlot and followed to slaughter to ensure accountability for all cattle enrolled in the study according to food use approval, or euthanized and necropsied. The decision to remove an animal from the treatment phase was made by the investigator or manager. Animals found dead at the time of observation were removed from the pen as soon as possible and necropsied (if possible).

[0122] Dietary formulation and feed assays Starting within approximately 70 days, animals were administered rumensin (monensin 46.3 mg kg -1 100% DM basis, Elanco (Greenfield, Indiana, USA) and Tylan (tylosin 8.9 mg kg -1 The LUB-treated cows were fed a diet containing 100% DM basis (Elanco). At the beginning of the treatment period (d-57), the cows were switched from the basal feeder ration to a feeder ration containing the appropriate concentration of LUB Type A premix. Table 5 shows the composition and formulated nutrients of the feeder rations. The composition is listed below. The diets were designed to meet or exceed the minimum nutritional requirements cited in the Nutrient Requirements of Meat Cattle (NASEM, 2016). LUB was delivered to the cattle using a 1% LUB Type A premix prepared and delivered by Elanco (Clinton Laboratories, Clinton, Indiana, USA), and the daily amount of feed was prepared on-site at the study facility. The Type A premix was delivered to the daily feed amount by running 1% Type A premix with water through a micro-ingredient machine (Micro Technologies, Amarillo, TX, USA), which was included at an "in-kind" daily feed amount of approximately 27 kg for each 3,629 kg batch. The 1% Type A premix was added at 0, 0.0154%, 0.0353%, or 0.0551% (100% DM) and included in the daily fattening ration, CON, 1.5, 3.5, or 5.5 mg kg -1 LUB (100% DM) was obtained. The on-site feed mixers used to mix (static horizontal paddle mixer [Cactus Varied Industry, Amarillo, TX, USA]) and deliver (Roto-Mix 490-14 and Roto-Mix 620-16, Roto-Mix LLC, Dodge City, KS, USA) the Type C diets were qualified to ensure uniform mixing of the daily diet amount before feeding. Cows received either CON, 1.5, 3.5, or 5.5 mg kg -1 The animals were fed in the order of the dose of LUB. Before mixing the CON batch, the appropriate amount of unmedicated feed or other cattle feed was flushed through the mixer to ensure there was no carryover of the test compound. Feeding occurred three times daily at approximately the same time each day. The feed trough decision was made at the first feeding, and the amount of feed at the third feeding was adjusted based on the daily feed trough decision according to facility procedures. The feeding goals were to have an empty trough before the first feeding, approximately one-third of the cattle in the trough, one-third of the cattle moving to the trough, and one-third of the cattle not moving to the trough at the first feeding. Water was available ad libitum throughout the study. The weight of the feed provided was recorded to provide an electronic feed log for data analysis. [Table 5]

[0123] Samples (separate samples for LUB and nutrient analysis) were collected weekly from each treatment (d-57 to d-1) of the daily amount of feed prepared for analysis. Duplicates consisting of a composite of three samples from different locations within the delivered truck load were used as either the primary or backup sample. Weekly primary samples were analyzed for LUB at Eurofins Laboratories (Greenfield, Indiana). Backup samples were frozen. Feed assays were performed using a validated analytical method for LUB (Determination of Lubabegron in Medicated Feed by High-Performance Liquid Chromatography: Laboratory Procedure G1635). The allowed analytical variation for LUB content in a single feed analysis (weekly composite) was 1.5 mg kg -1 ±25% for truck loads, 3.5 and 5.5 mg kg -1 Truck shipments were ±20%.

[0124] Samples for nutrient analysis were freshly submitted to Servi-Tech Laboratories, Inc. (Amarillo, TX) on the day the samples were collected. Analyses included DM (dry matter obtained by oven drying at 105°C for 3 hours per National Forage Testing Association procedure #2.1.4), CP (AOAC #990.03), N (%CP ÷ 6.25), non-protein nitrogen (NPN) (AOAC #941.04), acid detergent insoluble nitrogen (ADIN) (AOAC #2001.11), and Ca and P (AOAC #990.08).

[0125] Feeding and growth performance Animals were weighed individually at randomization (approximately d -69 to d -66), and this weight was used to exclude steers with extreme BW from the study. All other BW (uncontracted) was collected by pen and used to calculate growth performance. Scheduled pen weights were collected before feed delivery and on day -59 (2 days before treatment initiation, considered treatment start weight) and day 0 (1 day after treatment termination, considered treatment end weight). Before each collection of animal weights, the weighing machine was qualified according to the study facility's operating procedures.

[0126] Feed weight subtractions (if feed remained in the trough) occurred on days -57, -1, 0, and as needed due to soiled, spoiled, or excessively wet feed. When feed weight subtractions occurred between days -59 and 0, a composite sample of feed weight subtractions from all troughs was collected, and the DM was determined for each sample at the test facility. Average daily DMI was calculated by subtracting the weight from the amount offered as in-kind feed the previous day, then multiplying the in-kind feed intake by the DM provided, adjusted for the total number of animal days during the treatment period. Average daily gain (ADG) (kg·hd) -1 ) was calculated over the entire 56-day treatment period using unshrunk BW (kg), excluding animals removed during the treatment period. Gain efficiency was summarized as gain:demand quotient (ADG:DMI).

[0127] Animal mobility Animal mobility assessments were conducted three times before harvest: 1) while the cattle were in the stall approximately one week prior to harvest; 2) after final weighing in the stall and immediately prior to loading onto the slaughter truck; and 3) at an antemortem examination during the animal staging area at the food processing plant. Mobility scorers assessed cattle mobility using the North American Meat Institute (NAMI) Mobility Score System (Edwards-Callaway et al., 2017). The NAMI mobility scoring system is a four-point scoring system, where 1 indicates typically walking easily with no obvious lameness or gait changes; 2 indicates keeping up with normal cattle during group walking but exhibiting one or more of the following: stiffness, narrow stride, or slight limp; and 3 indicates not keeping up with normal cattle during group walking and exhibiting one or more of the following: obvious stiffness, difficulty walking, obvious limp, or discomfort. 4 is very reluctant to move even when prompted by handlers.

[0128] Slaughter and carcass characteristics To comply with the FDA-granted food use authorization (FDA, 2016), LUB was removed from the diet at least 24 hours before harvest. Immediately after collecting final live weight in the stall, cattle were transported to the slaughter facility for harvesting in a semitrailer truck at a stocking density of approximately 30 steers (i.e., half of the 60 steers in the stall). The slaughter process followed USA requirements and standard slaughter facility procedures. Animal / carcass identification was maintained by trained personnel from the Beef Research Center (BCRC, West Texas A&M University, Texas) who sequentially recorded cattle ear tag numbers at slaughter via sequential numbers affixed to each carcass and correlated individual ear tag numbers with plant-assigned carcass ID numbers, which remained intact throughout the carcass data / sampling phase. Each carcass was weighed to determine HCW according to industry-standard carcass yield procedures.

[0129] Carcass evaluation was performed after the standard chilling period at commercial plants. Carcass quality and yield grade factors, marbling score, loin eye area, and 12th rib fat thickness were objectively captured using a VBG2000 camera system. In addition, adjusted 12th rib fat thickness, kidney-pelvis-heart (KPH) fat assessment, and other defects (e.g., dark cutters, blood spatter) were recorded by trained personnel (BCRC). Skeletal maturity was only obtained for carcasses with a "B" maturity rating or higher. Other criteria, such as skeletal maturity, lean maturity, and overall maturity, and meat color criteria, were not available.

[0130] Carcass defects (dark cutters, excessive trim) were noted in exceptional cases. Objective fat thickness was used to calculate USDA yield grades. Because all carcasses were considered under 30 months of age, USA meat quality grades were determined using marbling scores (USDA, 2019). The severity of the dark cutter condition was indicated by assigning dark-cut carcasses to the 1 / 3, 2 / 3, or full dark category. Dark cutters were not excluded when determining meat quality grades, but an overview of the frequency of carcasses that received dark cutters by treatment group is provided. Carcasses identified as overtrimmed (>9.1 kg of trim) were not excluded from the analysis, but an overview of the frequency of overtrimmed carcasses by treatment group is provided.

[0131] statistical analysis period and HCW (e.g., kg of gas in BW) -1 or g kg of gas -1 The label claim variable of cumulative NH3 outgassing over the treatment period normalized by final BW (with BW at d-59 as a covariate) for HCW was determined utilizing the NH3 outgassing equation developed from the LUB clinical efficacy study (FDA-FOI, 2018) and validated using animals with BW similar to that described in Brown et al. (2019). The pen was the experimental unit for each outcome. P trt Differences were considered significant using a two-tailed test at ≤0.05, but P trtA less stringent significance threshold of ≤0.10 was used for abnormal health observations. Fixed effects for treatment and random effects for time repeat and block within time repeat were included in the model. Discrete variables were analyzed using generalized linear mixed models, Proc GLIMMIX SAS version 9.4. A binomial distribution was assumed, and a logit link was used in the analysis, unless there were convergence issues due to data sparseness. Contrasts were constructed between the CON group and each non-CON dose group, and differences were considered significant when Pdose ≤0.05. When convergence issues occurred due to data sparseness, Fisher's exact test (binomial data, Proc FREQ in SAS) or Wilcoxon rank sum test (categorical data, Proc NAR1WAY in SAS) was used to assess differences between the CON and non-CON dose groups. For these main discrete variables, except for health observations, P was ≤0.05. trt Differences were considered significant at P ≤ 0.05. dose Comparisons were made with each other using a significance level of ≦0.05. trt A ≦0.10 level of significance was used for health observations.

[0132] Continuous variables were analyzed using linear mixed models, Proc MIXED SAS version 9.4. For discrete variables, P trt Differences were considered significant at ≤0.05. Where required by protocol, BW on d-59 was included as a covariate in the analysis of the main non-claim variables (ANCOVA): final BW, HCW, and DMI. This covariate remained in the model regardless of its statistical significance. Contrasts were constructed between the CON and each non-CON group, and differences were assessed at P dose A P < 0.05 was considered significant. Variables with statistically significant contrasts were tested to determine whether the dose-response followed a linear or quadratic fit. Additionally, the non-CON group was compared at P dose Comparisons were made with each other using a significance level of ≦0.05.

[0133] result Feed composition and LUB assay The ingredient composition, analyzed nutrient content, and formulated nutrient and monensin / tylosin composition of the fattening diets fed during the 56-day treatment phase are shown in Table 5. CON, 1.5, 3.5, or 5.5 mg kg -1 LUB assay results for the treatment groups (average of 11-week samples taken during the treatment phase and range) were 1.34 (1.19–1.47), 3.13 (2.89–3.56), and 4.93 (4.63–5.28) mg kg on a 100% DM basis, respectively. -1 All LUB feed assay results were within the specified tolerance ranges. Daily LUB consumption was measured at CON, 1.5, 3.5, or 5.5 mg kg -1 0, 13.8, 32.6, and 50.8 mg hd in the treatment groups, respectively. -1 It was.

[0134] Animal Health Table 6 summarizes abnormal health observations and animal removals that occurred after treatment initiation. Significant differences (P trt Total eliminations (animals found dead and all animals removed from the treatment phase for health reasons) for each treatment group were 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29 ... -1 The % fertility rates were 1.7, 2.5, 1.5, and 1.8% for the treatment groups, respectively. All cattle passed routine USDA antemortem inspection. Two steers were not harvested due to hyperactive temperament. One steer (3.5 mg kg -1 One steer (treatment group) was euthanized at the food processing plant and not harvested. The second steer (CON group) was returned to the research facility and slaughtered at a later date. Carcass data from these two steers were not included in the analysis. [Table 6]

[0135] Animal mobility Table 7 summarizes the animal mobility assessments performed before harvest. There were no differences (P < 0.05) between treatments for the proportion of cows scoring 1 at any time point. trtNo abnormalities (≥ 0.17) were observed. Cows scoring 1 or 2 represented 92% or more of the animals at any one time. For animals receiving an abnormal score > 2, there were no differences between treatments at any of the preharvest assessment times. [Table 7]

[0136] Growth performance and carcass characteristics Initial BW did not differ between cows assigned to the different treatments (P trt = 0.709). However, final BW and HCW increased by 11.6–15.7 kg and 11.3–17.1 kg, respectively, in cows fed LUB compared with CON (P trt <0.001) (Table 8). Average daily weight gain (P trt < 0.001) resulted in an 11.3% to 15.5% increase in DMI (P < 0.001) in cows fed LUB compared with CON. trt = 0.025) was 2.0% to 3.0%.

[0137] Efficiency of gain (ADG:DMI) was improved by 9.0% to 12.0% in LUB-treated cows compared with CON (P trt Carcass yield increased by 0.7–1.2% and loin area increased by 3.3–5.7 cm2 in LUB-treated cattle compared with those in the CON group (P < 0.001). trt < 0.001). Marbling scores were 13 to 27 units higher (P < 0.001) compared with CON. trt <0.001) and the yield grade was 7 to 20 points (P trt The CON group, 1.5 mg kg-1 LUB group, 3.5 mg kg-1 LUB group, or 5.5 mg kg-1 LUB group had a significant reduction (<0.001). -1 For the LUB group, the frequencies of over-trimmed carcasses were 1.1% (8 / 707), 1.4% (10 / 702), 1.8% (13 / 708), and 1.4% (10 / 707), respectively (data not shown).For the CON group, 1.5, 3.5, or 5.5 mg kg -1For the LUB group, the frequency of carcasses with dark cutters was 0.3% (2 / 707), 0.6% (4 / 702), 0.3% (2 / 708), and 0.1% (1 / 707), respectively (data not shown). Yield grade 2 was 3.5 and 5.5 mg kg compared with CON. -1 The LUB group showed an increase in trt ≦0.05), and yield grade 4 decreased in all LUB groups (P trt ≤ 0.05) (Table 9). Compared with CON, 3.5 and 5.5 mg kg -1 In the LUB group, the meat quality judgement of Select grade increased (P trt ≦0.05), and meat quality ratings in the top two / thirds of choice grades decreased in all LUB groups (P trt ≦0.05). [Table 8] [Table 9]

[0138] conclusion Daily dry matter intake was 2.3% greater in steers fed LUB (Ptrt < 0.05). Mean daily gain was 13.7% greater in steers fed LUB (Ptrt < 0.05; 1.68 vs. 1.91 kg), but gain efficiency was 10.8% greater (Ptrt < 0.05; 0.167 vs. 0.185). Animal mobility was scored in the pen approximately one week before harvest, when cattle were loaded onto trucks scheduled for harvest, and at antemortem examinations in the livestock lair. No treatment differences (Ptrt ≥ 0.170) were observed at any time point in the percentage of cattle achieving a mobility score of 1 or 2 (normal or slightly stiff but able to move with normal cattle, respectively). Mobility for cattle scored 1 or 2 was consistently equal to or greater than 92%. Final BW and HCW increased by 11.6–15.7 kg and 11.3–17.1 kg, respectively, in cows fed LUB compared with cows receiving monensin + tylosin alone (Ptrt<0.05).

[0139] Example 3: Effect of rubabegron withdrawal period on ante-mortem performance and carcass characteristics of steers This study was conducted to evaluate the effect of removing rubabegron from the diet to increase the pre-slaughter interval on the growth performance of steers.

[0140] Cattle and treatment Seven hundred British x Continental crossbred steers (initial BW = 531 ± 8.8 kg) were used in a randomized complete block design with seven treatments. The pen served as the experimental unit. Treatments included 3.5 mg / kg DM rubabegron or an untreated control diet containing no rubabegron-containing diet fed for 56 d, with an additional voluntary removal of 0, 2, 4, 6, 8, or 16 d before harvest (Table 2). Animals were housed in two replicates, with each replicate containing five blocks (seven pens / block and 10 steers / pen). All 10 blocks started and ended within 48 h of each other. Cows were weighed by stall using a 45,000 kg capacity stall weigher (Model WI-130, Avery Weigh-Tronix LLC, Fairmont, MN, 3.66 m x 21.34 m). All treatments were fed 71 d and harvest was scheduled for 72 d. Due to an impending weather event, cows were weighed and final BW was advanced by one day. Cows were fed their respective daily feed amounts for the additional day and then transported to the harvest facility the following morning.

[0141] Feed and Mixing Procedures In both studies, diets (Table 3) were formulated to meet or exceed the nutritional requirements of finishing beef cattle (NRC, 2016). Mixing procedures and feeding methodologies were similar in both studies. Diet homogeneity was confirmed before the start of the experiment, and the mixer scale was verified before each day of use. Diets were prepared using a static mixer (Kirby Model 705; 20.0 m3 volume). Rubabegron was added to the daily ration via water wash from a micro-ingredient machine. The ration was transferred to a trailer-mounted mixer (Kirby 475; 13.5 m3 volume), where the cattle were fed once daily.

[0142] Harvesting and tissue collection 657 animals were transported from the research facility to a harvest facility approximately 495 km away. While in the livestock holding area, animals were scored for mobility using the North American Meat Institute (NAMI, 2015) scoring scale described in Edwards-Callaway et al. (2017). The mobility scoring system is a four-point scoring system, where 1 indicates easy walking, typically with no obvious lameness or gait changes; 2 indicates keeping up with normal herd populations but exhibiting one or more of the following: stiffness, narrow stride, or slight limp; 3 indicates not keeping up with normal herd populations and exhibiting obvious stiffness, difficulty walking, obvious limp, or discomfort; and 4 indicates extreme reluctance to move, even when prompted by handlers. Experienced staff collected ear tag numbers, plant identification (ID), and carcass order and applied unique carcass IDs. Data collected at the slaughter floor included HCW, instances of excess trimming (>approximately 9 kg), and the prevalence of liver abscesses (Brown et al., 1975). Other carcass measurements were obtained via instrument grading. The remaining 35 animals were transported to a different facility located approximately 80 km from the study site to facilitate tissue collection (liver, muscle, cusp, reticulum, and adventitia) at harvest.

[0143] feed Dry matter intake (DMI) was determined by the difference between the delivered and remaining diets. Dietary DM was determined weekly by oven drying (100°C for >12 hours). Dietary samples were collected weekly from randomly selected batches of each diet for both nutrient and rubabegron analysis. Composite samples (approximately 2 kg) for each analysis x diet were generated by combining three subsamples taken from each third of the selected batch. Composite samples were stored at -20°C until submission. Composite diet samples were submitted to MVTL Laboratories (New Ulm, MN) for crude protein (AOAC, 2019; Method 990.03), calcium, and phosphorus (AOAC, 2019; Methods 968.08 and 985.01).

[0144] statistical analysis Continuous variables were analyzed using the SAS mixed procedure (version 9.4, SAS Institute, Cary, NC). Block served as a random effect, but treatment was fixed. Initial body weight was used to account for the uniformity of cows randomized to treatment and was used as a covariate when appropriate. Data were calculated excluding deaths and removals. Linear and quadratic effects of rubabegron removal were performed, as were individual comparisons of removal duration (i.e., 0 vs. 2 days, 0 vs. 4 days, 0 vs. 6 days, 0 vs. 8 days, and 0 vs. 16 days). Fisher's exact test was evaluated for mobility scores of 1 and 2. Tests were not performed for mobility scores of 3 or 4 because the scores were not reported. Simple means and standard deviations were calculated for tissues collected from five animals.

[0145] result Cows within treatment on Day 0 had either 1 day 0 hours 4 minutes or 1 day 1 hour 49 minutes of withdrawal due to transport time to the facility and time in the livestock lair. The smaller group of 35 animals had a removal period of 17 hours 21 minutes.

[0146] Results of the withdrawal period on growth performance are shown in Table 10. Carcass weight was lower (395 kg) in untreated cows compared with similarly treated cows within the 0-day withdrawal group (409 kg) (P<0.001). Carcass weights for cows fed rubabegron ranged from 408 to 413 kg among the other treatments. Carcass yield followed a similar pattern to HCW. Carcass yield was 61.7% for cows in the untreated group and ranged from 62.6% to 63.0% for the other treatment groups. Marbling score was reduced (P<0.001) in cows fed rubabegron. Marbling score (551) was higher in the untreated group compared with marbling scores ranging from 482 to 491 in the treated groups (P<0.001). Loin eye area (REA) was increased (P<0.001) in cows fed rubabegron. Carcass REA averaged 83.1 cm in the untreated group. 2 REA was 89.7-91.6cm for other procedures. 2 Calculated yield grade data showed leaner results when fed rubabegron (P<0.01). Calculated yield grade improved by 10.5% when comparing untreated groups to cows fed rubabegron for 56 days at 0 day removal (P<0.001, 3.44 vs. 3.08). Calculated yield grades ranged from 3.06 to 3.21 for all rubabegron treatment groups. Again, there was no effect of removal period on any measured carcass parameter (P>0.05). [Table 10]

[0147] Animal mobility was assessed in cows presented for harvest (Table 11). Across all treatments, approximately 97.3% were scored as a 1 during the assessment, and 2.7% were scored as a 2. No differences were observed when fed rubabegron (P<0.25), but mobility tended to decrease with increasing removal periods (P<0.06). Four animals died during the experiment: three died from bloat and one died from posterior vena cava thrombosis. Four animals were removed due to respiratory disease (2), lameness (1), and incorrect stall assignment (1). These losses were not believed to be related to the treatment.

[0148] This study demonstrates that the effects of rubabegron on BW and HCW were unaffected by withdrawal periods of up to 16 days. This was surprising, as the effects of beta-adrenergic receptor blockers on animal performance have been inconsistent. Bryant et al. (2010) reported no decrease in BW or HCW with increasing withdrawal periods, whereas Rincker et al. (2021) demonstrated a decrease in HCW of -0.4 kg / day with increasing withdrawal periods. In both studies, the withdrawal period was up to 8 days. Holland et al. (2010) fed zilpaterol at 8.3 mg / kg dietary DM followed by withdrawal periods of 3, 10, 17, or 24 days before harvest. However, final BW and carcass-adjusted final BW were not affected by zilpaterol feeding (P ≥ 0.14). Differences of 14, 17, 5, and 6 kg in HCW between zilpaterol-fed and untreated cows were noted when removed on days 3, 10, 17, and 24, respectively. At longer removal times, treated animals tended to be similar to untreated cows. [Table 11]

[0149] Each article is incorporated herein by reference in its entirety. [Prior art documents] [Non-patent literature]

[0150] [Non-Patent Document 1] Brown, H., RF Bing, HP Grueter, JW McA skill, CO Cooley and RP Rathmacher. 1975. Chlorotetracycline for the prevention of liver abscesses, improved weight gain and feed efficiency in feedlot cattle. J. Anim. Sci. 40:207. doi.org / 10.2527 / jas 1975.402207x. [Non-patent document 2] Brown, M. S., N. A. Cole, S. Gruber, J. Kube, and J. S. Teter. 2019. Modeling and prediction accuracy of ammonia gas emissions from feedlot cattle. Applied Anim. Sci. 35:347. doi / 10.15232 / aas.2018-01934. [Non-patent document 3] Edwards-Callaway, LN, MSCalvo-Lorenzo, JAScanga, and T. Grandin. 2017. Mobility scoring of finished cattle. Vet. Clin. North Am. Food Anim. Pract.33:235-250. doi:10.1016 / j.cvfa.2017.02.006. [Non-patent document 4] Guelker , MR , Haneklaus AN , Brooks JC , Carr CC , Delmore Jr RJ , Griffin DB , Hale DS , Harris KB , Mafi GG , DDJohnson , et al. 2013. National Beef Tenderness Survey-2012: Warner-Bratzler shear force values ​​and sensory panel ratings for beef steaks from United States retail and food service establishments. J. Face. Sci. 91:1005–1014. doi:10.2527 / jas2012-5785.

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Claims

1. 3.5-22mg*kg －１ 2. A method for improving the growth performance of feedlot cattle, comprising administering to the cattle an effective amount of rubabegron or a physiologically acceptable salt thereof at a dry matter dose of 100 mg / kg of feedlott or 100 mg / kg of feedlott.

2. The amount of rubabegron or a physiologically acceptable salt thereof is 5.5 mg*kg －１ 10. The method of claim 1, wherein the medicament is administered at a dry matter dose of

3. 3. The method of claim 1 or 2, wherein the administration is for 56 to 91 days.

4. 4. The method of claim 3, wherein said administration is during the last 56 to 91 days of said finishing period.

5. 4. The method according to claim 1, wherein the rubabegron is removed 2 to 16 days before harvest, and the improved growth performance is not significantly attenuated by the removal of rubabegron.

6. 4. The method of claim 1, wherein the rubabegron is removed 2 to 16 days before harvest, and wherein the final body weight (BW), hot carcass weight (HCW), average daily gain (ADG), gain / feed ratio (G:F), dry matter intake (DMI), carcass yield, loin eye area or longissimus dorsi muscle area (LM area), yield grade (YG), and / or yield grade distribution are not significantly attenuated by the removal of rubabegron.

7. 7. The method of claim 5 or 6, wherein the rubabegron is removed 16 days before harvest.

8. 8. The method of any one of claims 1 to 7, wherein the administration results in an increase in final body weight (BW) of at least 11 kg compared to control cattle not administered rubabegron.

9. 9. The method of any one of claims 1-8, wherein the administration results in an increase in hot carcass weight (HCW) of at least 15 kg compared to control cattle not administered rubabegron.

10. 8. The method of any one of claims 1-7, wherein the administration results in an increase in average daily gain (ADG) of about 11% to 16% compared to control cattle not administered rubabegron.

11. 8. The method of any one of claims 1 to 7, wherein the administration increases the gain / feed ratio (G:F) by at least 10% compared to control cattle not administered rubabegron.

12. 8. The method of any one of claims 1-7, wherein said administering increases dry matter intake (DMI) by said cow by about 2% to 3% compared to control cows not administered rubabegron.

13. 8. The method of any one of claims 1 to 7, wherein the administration increases the loin eye area compared to control cattle not administered rubabegron.

14. 8. The method of any one of claims 1 to 7, wherein the administration increases the carcass yield compared to control cattle not administered rubabegron.

15. 15. The method of claim 14, wherein the carcass yield increases by about 0.9 to 1.3 units.

16. 8. The method of any one of claims 1-7, wherein the administration reduces yield grade (YG) compared to control cows not administered rubabegron.

17. 17. The method of claim 16, wherein the YG is reduced by about 10% to 11% compared to control cows not administered rubabegron.

18. 8. The method of any one of claims 1 to 7, wherein the administration improves yield grade distribution compared to control cows not administered rubabegron.

19. 20. The method of claim 18, wherein a greater percentage of the cows are in yield grade 2 compared to control cows not administered rubabegron.

20. 20. The method of claim 18, wherein a lower percentage of the cows are in yield grade 4 compared to control cows not administered rubabegron.

21. The method according to any one of claims 1 to 20, wherein the physiologically acceptable salt is rubabegron fumarate.

22. The method according to any one of claims 1 to 21, wherein the rubabegron or a physiologically acceptable salt thereof is administered in feed.

23. A method for reducing kidney, pelvis, and heart fat (KPH) in feedlot cattle, comprising administering to the cattle an effective amount of rubabegron or a physiologically acceptable salt thereof.

24. The amount of rubabegron or a physiologically acceptable salt thereof is 22 mg*kg －１ 24. The method of claim 23, wherein the dose is

25. 25. The method of claim 23 or 24, wherein the physiologically acceptable salt is rubabegron fumarate.

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