Zootechnical additive for insects

Abstract

The invention concerns the use of at least one amino acid analogue or a protein as a zootechnical additive for the feed of livestock insects, said amino acid analogue being selected from selenomethionine, 2-hydroxy-4-methylthiobutanoic acid and 2-hydroxy-4-methylselenobutanoic acid and the protein being selected from phytases and non-starch polysaccharide degradation enzymes (NSP-ases); a food for livestock insects; a method for supplementing the feed of livestock insects and a method for increasing the performance of insect breeding.

Description

[0001] DESCRIPTION

[0002] TITLE: Zootechnical additive for insects

[0003] The present invention concerns the supplementation of the feeding of insects, in particular of livestock insects.

[0004] The entomoculture, namely the insect breeding, on an industrial scale, has proven for several years to be a viable and sustainable alternative forthe environment to conventional proteins, in particular of animal origin, and also as a source of food for monogastric farmed animals, in particular pigs and poultry, as well as for fish in aquaculture. This production mobilizes few resources, especially water, food and space, it releases only a small amount of greenhouse gases, resulting in a significantly reduced ecological footprint compared to conventional protein production. Insects are also able to feed on organic waste, and their nitrogen-laden droppings are effective agronomic fertilizers, which further enhances their interest. In human or animal food, they are eaten alive in some countries, or dried, or used in the form of flour generally obtained by dehydration then crushing, or of extracts such as oils, and constitute a fraction or a food supplement rich in protein, omega-3 and low in fat.

[0005] According to the invention, there is an interest in the industrial production of insects and it has been discovered that the introduction of some compounds into the food of insects makes it possible to increase their performance in a surprising manner.

[0006] By increased performance according to the invention it should be understood an increase in the body biomass yield of the farmed insects compared to that of farmed insects under the same conditions but with a food not supplemented by an additive of the invention, related in particular to a gain in weight per insect and / or an acceleration of their reproduction, resulting from a better bioavailability of the constituents of their food.

[0007] These compounds are analogs of amino acids and proteins, more specifically enzymes. Indeed, it has been discovered that the supplementation of insect feeding with one or more of the following compounds, selenomethionine, 2-hydroxy-4-methylthiobutanoic acid, 2-hydroxy-4- methylselenobutanoic acid, phytases and enzymes for the degradation of non-starch polysaccharides (NSP-ases), leads to better valuation of the food ration by insects.

[0008] Thus, the invention concerns the use of at least one amino acid analogue or a protein as a zootechnical additive for the feed of livestock insects, said amino acid analogue being selected from selenomethionine, 2-hydroxy-4-methylthiobutanoic acid (HMTBA) and 2-hydroxy-4- methylselenobutanoic acid (HMSeTBA) and the protein being selected from phytases and NSP-ases.

[0009] Some of these compounds are used for supplementing the feed of farmed animals, precisely livestock and poultry. Compared to conventional livestock species, data on the physiology of the intestine of insects which are invertebrates are scarce. The digestive tract of insects starts with a mouth apparatus. In particular for insects having a larval stage, the mouth part may have a well-developed mandibular-maxillary complex that contains a sweeping apparatus like those of scavengers’ larvae to improve the efficiency of uptake of organic materials. The maxillary rasp as well as the lacinial teeth of the larval mouth apparatus are used to grind the particles picked up from the semiliquid substrate. Subsequently, pretreated particles are transported to the pharynx after sorting, reaching the “grinding mill” where they are further crushed. Following the mouth part, the intestine is divided into three main parts, which can be further subdivided into different functional units. The three-compartment organization of the digestive system is conserved in all insects. The gastrointestinal tract (GIT) consists of i) the foregut, the anterior part of the alimentary canal involved in food ingestion, storage, and disintegration, ii) the midgut, where food digestion and nutrient absorption take place, and iii) the hindgut. This last part of the GIT is responsible for the reabsorption of water and ions coming from the hindgut contents and urine derived from Malpighian tubules which enter the hindgut, and is also the site of absorption of amino acids. Amino acid uptake in the hindgut of insects differs from the generally accepted concept in vertebrates, in which no amino acid uptake takes place in this intestinal compartment.

[0010] There is a major knowledge gap when it comes to the definition of amino acids and proteins requirements of insects, such as black soldier flies.

[0011] Given the lack of knowledge of the insect metabolism and the differences between farmed animal metabolism and what little is known about insect metabolism, the effects of the invention are unexpected.

[0012] The invention is described in more detail and different implementation are exposed.

[0013] According to one or several variants of the invention, one, two or three of the amino acid analogues and / or one or several of said enzymes are used. According to a particular variant, at least one of selenomethionine, 2-hydroxy-4-methylthiobutanoic acid and 2-hydroxy-4-methylselenobutanoic acid; a phytase; and an NSP-ase are used. According to another particular variant, at least 2-hydroxy- 4-methylthiobutanoic acid, 2-hydroxy-4-methylselenobutanoic acid, a phytase and an NSP-ase are used. It is thus possible to consider all the possible combinations, and it is possible to use a single one amongst selenomethionine, HMTBA and HMSeTBA, or a mixture of two or three of said amino acid analogues; a phytase or a mixture of phytases and / or an NSP-ase or a mixture of NSP-ases may be used; and of course all of these alternatives may be combined. By way of examples, it is possible to use a mixture of enzymes selected from those described in the documents W02009 / 019335A2 and WO99 / 57325A2.

[0014] Phytases degrade phytates and phytic acid found in plant food sources by hydrolysis of phospho-ester bonds to release mineral phosphorus. There are two subclasses of phytases, differentiated only by the position of the first hydrolyzed phosphate. 3-phytases (EC 3.1.3.8) hydrolyze phosphate in position 3 and 6-phytases (EC 3.1 .3.26) hydrolyze phosphate in position 6. According to the invention, a 6-phytase is preferably used. It has a very high phytate degradation activity, especially at low pH. Such a phytase may be produced by microorganisms or provided by a plant raw material.

[0015] NSP-ases are enzymes that degrade non-starch polysaccharides (NSP). The food fraction called food fiber is made up of those NSPs which include long-chain non-starch carbohydrates, such as celluloses, pectins and glucans; medium-long chain resistant carbohydrates such as fructo- oligosaccharides and galacto-oligosaccharides; resistant starch; and lignin which is not a carbohydrate but is nevertheless included in the NSPs [O. Simon. 1998. The mode of action of NSP hydrolysing enzymes in the gastrointestinal tract. J.Anim. Feed Sci. 7 (Supp. 1):115-123], NSP-ases break down NSPs into smaller components, such as oligosaccharides, disaccharides, monosaccharides. By way of non-limiting examples, there are mannanases [S. Dhawan and J. Kaur. 2007. Microbial mannanases: an overview of production and applications. Crit. Rev. Biotechnol. 27(4):197-216]; carbohydrases [M. Francesch and PA Geraert, 2009. Enzyme complex containing carbohydrases and phytases improves growth performance and bone mineralization of broilers fed reduced nutrient corn-soybean-base diets. Poult. Science. 88:1915-1924], Commonly, a xylanase which will initiate the degradation of the polysaccharides is used; advantageously, in order to complete the hydrolysis process, one or several other NSP-ases are associated therewith.

[0016] It has been observed that the combination of at least two different compounds selected from the three amino acid analogues and said enzymes can be synergistic, leading to an unexpected increase in biomass. In an advantageous variant, at least one phytase and at least one NSP-ase will be combined. In another advantageous variant, this combination of at least one phytase and at least one NSP-ase will be supplemented with HMTBA.

[0017] According to an implementation of the invention, the insects are selected from those whose development passes through a larval stage. Moreover, an additive of the invention will advantageously be intended for the nutrition of insects at the larval stage, during all or part of this phase. Among these insects, interesting performances have been obtained in black soldier flies, abbreviated as BSF (Hermetia illucens).

[0018] Indeed, in some insects such as the BSF, the larval stage is the only stage where the insect seeks to eat. This will be its only objective, with the aim of making a reserve mainly of fat and also of sufficient protein to be able to develop into a nymph, then into a fly and reproduce.

[0019] The invention also provides a food for livestock insects, comprising at least one zootechnical additive as defined hereinabove and plant materials.

[0020] Other objects of the invention are described hereinbelow: a method for supplementing the feed of livestock insects, according to which a zootechnical additive of the invention is incorporated into the food of the insects. a method for increasing the performance of an insect breeding, comprising the step of feeding the insects with a feed comprising a zootechnical additive of the invention or a feed of the invention, as defined in the present text; advantageously, the insects have a larval stage, more particularly the insects are black soldier flies and are in the larval stage.

[0021] Advantageously, the feed is in the form of dry matter.

[0022] The feed of insects is brought by substrates of highly diversified origins, according to the species and its oral system. Flies and in particular BSF flies feed on organic substrates, for example residues from beer production. Suitable substrates are commercially available. According to the invention, the zootechnical additive(s) may be mixed with such a substrate, whatever its nature. The invention is illustrated in the following experimental part in support of [Fig. 1] to [Fig. 8] and its performance will be highlighted by the results obtained.

[0023] [FIG. 1], [FIG. 3], [FIG. 5] and [FIG. 7] illustrate the quantity of biomass in fresh larvae expressed in mg for each of the tests carried out with the additives HMTBA, SeMet, NSP-ases and phytase, respectively.

[0024] [FIG. 2], [FIG. 4], [FIG. 6] and [FIG. 8] represent the GPM expressed in mg as a function of the culture time expressed in days for each of the tests carried out with the additives HMTBA, SeMet, NSP- ases and phytase, respectively.

[0025] Different additives are tested by following the same protocol which is described hereinbelow.

[0026] First-generation black soldier fly larvae weighing 2.41 ± 0.00 mg each are placed in (40 x 60 x 15) cm culture trays at a rate of 84 g of larvae / tray. Each tray contains 12 kg of substrate. This is prepared from a classic larval rearing substrate comprising macronutrients, raw ash, calcium, phosphorus, amino acids (Arg, His, He, Leu, Lys, Met, Phe, Thr, Vai, Trp, Asp, Ser, Glu, Gly, Ala, Tyr, Cys, Pro) to which an additive of the invention is added. The mixture is then left to ferment for 3 days after which it is ready to receive the larvae for a period of 7 days. A control culture tray (Ctrl) is provided for each test whose substrate does not contain any additive.

[0027] For each additive, the test is repeated 6 times.

[0028] The following parameters considered as indices allowing the assessment of the performance of the additives were assessed:

[0029] Average weight gain (GPM)

[0030] Average daily gain (GMQ)

[0031] Specific growth rate (TCS)

[0032] Feed conversion rate (TCA)

[0033] Survival rate

[0034] They are not all shown in the examples hereinbelow.

[0035] Example 1 : Effect of 2-hydroxy-4-methylthiobutanoic acid (HMTBA)

[0036] A control (Ctrl) and two concentrations of HMTBA, 0.08% (HMTBA1) and 0.16% (HMTBA2), expressed by weight relative to the weight of the larval rearing substrate are tested.

[0037] The biomass (in kg) of larvae produced is measured. The results are reported in [Fig. 1], Whatever its content in the substrate, HMTBA has a highly favorable impact on larval growth.

[0038] The average weight gain (GPM) is measured. The results expressed in mg as a function of the culture time (in days) are reported in [Fig. 2] where - represents Ctrl; • represents HMATB1 and X represents HMTBA2. A positive effect of the supplementation of the substrate with HMTBA is observed, in particular from the fourth day of culture.

[0039] Example 2: Effect of selenomethionine (SeMet) A control (Ctrl) and two concentrations of SeMet, 2.50% (SeMetl) and 5.00% (SeMet2,) expressed by weight relative to the weight of the larval substrate, are tested.

[0040] The biomass (in kg) of produced larvae is measured. The results are reported in [Fig. 3], Whatever its content in the substrate, SeMet has a highly favorable impact on the larval growth.

[0041] The average weight gain (GPM) is measured. The results expressed in mg as a function of the culture time (in days) are reported in [Fig. 4] where - represents Ctrl; • represents SeMetl and X represents SeMet2. A positive effect of the supplementation of the substrate with SeMet is observed from the first day of culture.

[0042] Example 3: Effect of a mixture of NSP-ases

[0043] The mixture tested is marketed under the brand Rovabio® Advance which comprises a mixture of enzymes among which appear in the first place an xylanase (endo-1 ,4-beta-xylanase) and an endo- 1 ,3(4)-beta-glucanase.

[0044] A control (Ctrl) and two concentrations of NSP-ases, 100 ppm (NSP-ases1) and 200 ppm (NSP- ases2), are tested.

[0045] The biomass (in kg) of produced larvae is measured. The results are reported in [Fig. 5], Whatever their content in the substrate, the NSP-ases have a highly favorable impact on larval growth, even if at 400 ppm, there is less influence.

[0046] The average weight gain (GPM) is measured. The results expressed in mg as a function of the culture time (in days) are reported in [Fig. 6] where - represents Ctrl; • represents NSP-ases1 and X represents NSP-ases2. A positive effect of the supplementation of the substrate with NSP-ases is observed between the fourth and the fifth day and seems very significant between the fifth and the sixth day.

[0047] Example 4: Effect of a phytase

[0048] The phytase tested is marketed under the brand Rovabio® PhyPlus which contains a 6-phytase.

[0049] A control (Ctrl) and two concentrations of phytase, 100 ppm (phytasel) and 200 ppm (phytase2), are tested.

[0050] The biomass (in kg) of produced larvae is measured. The results are reported in [Fig. 7], Whatever its content in the substrate, phytase has a highly favorable impact on larval growth.

[0051] The average weight gain (GPM) is measured. The results expressed in mg as a function of the culture time (in days) are reported in [Fig. 8] where - represents Ctrl; • represents Phytasel and X represents Phytase2. A positive effect of the supplementation of the substrate with phytase is observed from the third day.

Claims

CLAIMS1 . A use of at least one amino acid analogue or a protein as a zootechnical additive for the feed of livestock insects, said amino acid analogue being selected from selenomethionine, 2- hydroxy- 4-methylthiobutanoic acid and 2-hydroxy-4-methylselenobutanoic acid and the protein being selected from phytases and non-starch polysaccharide degradation enzymes (NSP-ases).

2. The use according to claim 1 , of at least selenomethionine, 2-hydroxy-4- methylthiobutanoic acid, 2-hydroxy-4-methylselenobutanoic acid, a phytase and an NSP-ase, as a zootechnical additive for feeding livestock insects.

3. The use according to claim 1 or 2, characterized in that the protein or proteins is / are selected from 6-phytases.

4. The use according to any one of claims 1 to 3, characterized in that the insects are selected from those whose development passes through a larval stage.

5. The use according to claim 4, characterized in that the insects are in the larval stage.

6. The use according to any one of claims 1 to 5, characterized in that the insects are black soldier flies (Hermetia illucens).

7. A feed for livestock insects, comprising at least one zootechnical additive as defined in any one of claims 1 to 3 and plant materials.

8. A method for supplementing the feed of livestock insects, characterized in that a zootechnical additive as defined in any one of claims 1 to 3 is incorporated into the feed of the insects.

9. A method for increasing the performance of insect breeding, characterized in that the insects are fed with a feed comprising a zootechnical additive as defined in any one of claims 1 to 3 or a food according to claim 7.

10. The method according to claim 9, characterized in that the insects are black soldier flies and are at the larval stage.

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