RU2229827C2 - Method for increasing productivity in cattle and improving production quality - Google Patents

Abstract

FIELD: animal science. SUBSTANCE: the present innovation deals with supplementing the diet with probiotic preparation manufactured based upon somatoliberin-expressing recombinant Lactobacillus sp. 8PA3 (pLF-SL2) strain in digestive tract. The method enables to increase milk and meat performance in animals and improve the quality of production, that is: increase protein concentration in milk, increase the portion of muscular tissue and decrease fat content in meat. EFFECT: higher performance and improved quality of production. 4 ex, 5 tbl

Description

The invention relates to the field of animal husbandry, in particular the feeding of farm animals, and can be used in all types of farms with any form of ownership.

In recent years, in the practice of animal husbandry, in order to increase the productivity of animals with positive results, although variable, protein and peptide hormones have been tested, among which somatotropic growth hormone (STH) and somatotropic growth hormone releasing factor - somatoliberin - have shown the greatest promise. It was shown that they are effective in dairy cattle breeding [Ernst L.K., Torekhanov A.A. Milk productivity and the dynamics of metabolic processes in the body of cows when exposed to biosynthetic somatotropin. Agricultural. biology. 1995. No. 2. S.73-76; Pelletier G. et al. Biological effects of growth hormone releasing factor and level of feeding in lactating cows. J. Cell. Biol. 1990. V. 111. No. 5. P. 473; Dahl G.E. et al. Comparison of somatotropin and growth hormone-releasing factor on milk yield, serum hormones, and energy status. J. Dairy Sci. 1991. V. 74. No. 10. P. 3421-3428], pig breeding [Gorin OV, Artemenkov VV The effect of recombinant porcine somatotropin on meat and fattening qualities. Sat scientific tr. / Vseros. N.-i. select.genet. institute is alive. 1994. No. 1. S.155-156; Ryabykh V.P., Kalnitsky B.D., Ernst L.K. To the question of the use of somatotropin cascade genes for producing transgenic pigs with a given productivity potential and product quality. Genetic engineer S.-kh. animals. 1995. Issue. 1. S. 289-325; Bonneau M. Administration de GRF ou de somatotropine chez le pocr et les volailles: Effects sur les performances, la qualite des viandes et la function de reproduction. Prod. Anim. 1992. V. 5. No. 4. R.257-267], sheep breeding [Sainz R.D. et al. Exogenous growth hormone releasing factor and cottonseed meal improve growth performance and gain in lambs fed lucerne chaff ad libitum. Austral. J. Agr. Res. l994. V. 45. No. 6. P.1111-1123] and animal husbandry [Shulga L.V., Kazakova T.I. Growth hormone. Rabbit breeder. and beast grower. 1994. No5. S.11]. It was also established that the introduction of somatoliberin enhances the secretion of growth hormone in mammals and causes the same effects as the introduction of exogenous somatotropic hormone.

Currently, technologies have been developed for the production of STH and somatoliberin (from the endocrine glands, recombinant microorganisms) and schemes for their use (daily injections or prolonged-action drugs) have been proposed.

A disadvantage of the known methods of stimulating animal productivity by introducing STH or stimulating its endogenous formation with somatoliberin is the need for periodic injections, the high cost of the preparations and the complexity of these methods. Therefore, of practical interest is the development of inexpensive ways to increase the secretion of endogenous growth hormone in productive animals.

If the use of protein and peptide hormones through parenteral administration has been widely tested, the use of live recombinant strains of bacteria expressing the formation of these hormones by oral administration is still considered problematic. Proponents of this point of view motivate their position by the fact that protein molecules and peptides in an intact form from the intestines of young animals and adult animals are not absorbed. However, this idea is outdated, since a number of studies have shown that ovalbumin passes the intestinal barrier and is found in the blood almost unchanged. The absorption of proteins from the intestines is supported by numerous experiments on animals and isolated tissues, and some researchers have demonstrated the passage of high molecular weight protein fragments through an isolated jejunum of animals [Gardner M.L.G. Gastrointestinal absortion of intast proteins. Ann. Rev. Nutr. 1988. V. 8. P.329-350].

The aim of the invention is to provide a method for increasing animal productivity and improving product quality.

This goal is achieved by the fact that animals are orally given a genetically engineered recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2), carrying the somatoliberin gene and expressing its formation in the digestive tract of animals.

Strain Lactobacillus sp. 8 TIMES (pLF-SL2) was deposited in the All-Russian Collection of Industrial Microorganisms under registration number B-7495.

Distinctive features of the patented method are the following: the possibility of replacing laborious animal injections of exogenous somatotropin or somatoliberin with oral administration of a recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) expressing the formation of somatoliberin; the use of the drug for growth-promoting purposes and obtaining meat with a high content of muscle tissue and a reduced fat; increase in milk production of lactating animals and protein concentration in milk; stimulation of metabolic processes and the immune system in animals; the emergence of tolerance to somatoliberin in nascent young animals, whose mothers during pregnancy received a recombinant strain expressing the formation of STH releasing factor.

We have shown for the first time that oral administration of a recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) expressing the eukaryotic somatoliberin gene provides an animal response identical to that usually induced by exogenous somatotropin injections. Somatoliberin, which has absorbed from the intestines into the blood, stimulates the synthesis and secretion of hypothalamic nonapeptides, which, in turn, increase the production of STH in the adenohypophysis. In response to the increased intake of somatotropic hormone in the blood, intensive proliferation of cells in organs and tissues, an increase in protein synthesis in the liver and muscles, a decrease in the diameter of adipocytes in the subcutaneous adipose tissue, and an increase in the mitotic activity of chondrocytes in the bone tissue are observed. Stimulation of cellular activity in various organs and tissues is manifested by an increase to 30% (11-19% on average) of the increase in live weight and a change in the quality of meat in the direction of increasing muscle tissue in it and reducing fat content. In lactating goats, the average daily milk yield increases by 20.2-26.5% and the protein content in milk by 6.1-11.0%.

A complex of changes was revealed in the organs of the immune system of rabbits receiving a recombinant strain, indicating an increase in their immunopoietic function. In all structures of lymphoid organs, an increase in the number of young forms of lymphocytes and cells with figures of mitosis is observed.

Introduction to the diet of rabbits during pregnancy a recombinant strain of Lactobacillus sp. 8 times (pLF-SL2) was accompanied by an increase of 41% in the live weight of the nascent young. Subsequently, these animals grow better and, in response to the oral administration of a strain producing somatoliberin, give higher gains in live weight than rabbits obtained from mothers who did not feed the drug. Thus, after absorption, the somatoliberin formed by the recombinant strain penetrates the blood through the placental and blood-brain barriers and has a specific effect on the hormonal and immune systems that are formed in the embryos, causing the development of tolerance in the emerging young to this hormone.

The invention is illustrated by examples that characterize the biological characteristics of the effects of the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) on the body of animals, their productivity and product quality.

Example 1. The study of the effects of the strain of Lactobacillus sp. 8 TIMES (pLF-SL2), expressing the formation of somatoliberin, on the body of rabbits.

Conducted two experiments.

To conduct the 1st experiment, out of 45-day-old rabbits of one litter, 3 groups of 3 goals in each were formed. The first group served as a control and received the main diet (RR), and animals of the 2nd and 3rd groups were additionally given daily 1 ml of cultures of the initial probiotic strain Lactobacillus sp. 8 times and the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) expressing the formation of somatoliberin, respectively. The cultures were individually soldered to each rabbit from a pipette daily for a month. The animals were systematically monitored, and after a monthly application of the studied cultures, they were killed for hematological, pathological and morphological and histological studies.

For carrying out the II experiment, from crossbred rabbits (Californian × Soviet chinchilla breeds) of 45 days of age, 3 groups of 8 animals each were formed. All animals were placed in vivarium in mesh cells of 1-2 heads and received RR, which was balanced by the main nutrients in accordance with the norms of feeding. Animals of the 1st group, which were asked only PR, served as a control. Rabbits of the 2nd and 3rd groups daily, in addition to OR, received live cultures of the initial probiotic and recombinant strains of Lactobacillus sp. With the somatoliberin gene. 8 TIMES and Lactobacillus sp. 8 TIMES (pLF-SL2) respectively. The preparations were fed in a mixture with concentrates at a dose of 1 ml per head with a titer of 4-5 × 10 ⁹ colonies of forming units (cfu) / ml. The experiment lasted 3 months. For an objective assessment of the condition of the experimental animals, blood and urine were examined, and after 2 and 3-month feeding of the preparations, 3 animals from each group were killed in order to assess the effect of the studied strains on the pathological and histological state of organs, tissues and endocrine glands, as well as on the ratio of carcasses of muscle tissue, bones and fat.

The studies did not reveal any deviations in the functioning of the digestive, cardiovascular, circulatory, respiratory and genitourinary systems in rabbits. There were no cases of withdrawal of young animals receiving the drugs.

Hematological studies showed that in both experiments, the main parameters of the blood of animals (the number of red blood cells, white blood cells, hemoglobin, hematocrit, ESR) did not go beyond the physiological norm. At the same time, in the blood serum of rabbits receiving the initial and recombinant strains of Lactobacillus sp. the concentration of total protein increased by 28-32% (P <0.001), the phagocytic and bactericidal activity increased (P <0.05-0.001), and the concentration of lysozyme increased significantly. These data indicate that the studied strains of lactobacilli significantly increase the protective capabilities of the animal organism.

Urinalysis showed that both in the control and in animals treated with microbial preparations, its physicochemical parameters were within normal limits. Impurities of blood, bile pigments were not found in it, sugar, protein, ketone bodies and nitrates were not found. The urine was light brown in color, had a turbid, viscous consistency, had a characteristic odor for rodents, a relative density of 1.01-1.03, and a pH in the range of 6.5-8.0. Crystals of uric salts and single epithelial cells were present in the centrifugate of urine. These data indicate the normal function of the genitourinary system in both control rabbits and those receiving microbial preparations.

In both experiments, the rabbits of the control and experimental groups were clinically healthy, had good appetite, normally grew and developed. There was no significant difference in feed intake between the groups, and daily animals completely ate concentrates and 120-140 g of hay each.

In the 1st experiment, the initial probiotic and recombinant strains of Lactobacillus sp. 8 TIMES and Lactobacillus sp. 8 TIMES (pLF-SL2) were respectively set individually for each rabbit within a month. Weighing of the animals showed that the initial strain did not have a significant effect on the growth of rabbits, while the recombinant one increased their gross growth by 30.9% (Table 1).

Similar results were obtained in the second experiment, which lasted three months. The increase in live weight of group 3 rabbits in the first and second months of the experiment exceeded the control by 27.5% and 17.7%, respectively, and in the experiment as a whole by 19.7% (Table 1). At the same time, high rates were also observed with the use of the initial probiotic strain of Lactobacillus sp. 8 TIMES, which increased gross growth by 19%. The cost of feed units and digestible protein per 1 kg of growth in rabbits of the experimental groups decreased by 16-17%.

There were no significant differences between groups in the slaughter yield of carcasses, and it varied within 51-53%. However, the deboning of half carcasses showed that the proportion of muscle and fatty tissue did not remain constant. After 2 months of feeding the preparations, the percentage of muscle tissue from 69.4 in the control increased to 72.3 and 75.5 in the 2nd and 3rd groups, respectively, and the fat content decreased from 7.4% to 4.8% in The 3rd group receiving the supplement expressing somatoliberin strain Lactobacillus sp. 8 TIMES (pLF-SL2), while in the 2nd group, which was assigned the initial probiotic strain of Lactobacillus sp. 8 TIMES, the percentage of fat in the carcass increased to 9.5% (Table 2). In the meat of the hind legs of rabbits of the experimental groups, the dry matter content was statistically significantly (P <0.002), and in animals of the 3rd group there was a clear tendency to an increase in protein concentration and a decrease in fat level (Table 2), which, although indirectly, indicates on stimulation of the synthesis of endogenous growth hormone.

When conducting a post-mortem veterinary-sanitary inspection of the carcasses of rabbits killed after 1, 2 and 3 months of use of the preparations, no visible pathological changes were found in them.

Histological studies showed that in neurons of the supraoptic nucleus of the hypothalamus of rabbits receiving the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2), signs of increased functional activity were observed: large “bright” neurons with an oval or polygonal shape, a large vesicular nucleus and a small number of fine-grained granules located in a narrow strip around the nucleus predominated. The sizes of nuclei and cells of neurons were slightly higher than in control animals (Table 3).

Nonapeptides of the supraoptic nucleus of the hypothalamus are known to stimulate the DNA-synthetic activity of many cells, including those that enhance the proliferative activity of the adenohypophysis. Normally, the adenohypophysis is characterized by a low rate of proliferation of cell populations, and therefore it should be assumed that not all cells are involved in this process. The results of our studies indicate that the oral use of the strain of Lactobacillus sp. 8 TIMES (pLF-SL2), which expresses the formation of somatoliberin, stimulates the proliferation of epithelial cells in the adenohypophysis (Table 3). At the same time, rabbits of the 3rd group had 5% more somatotropocytes than control animals. An essential feature of activated adenohypophysis cells was an increase in their pool of free ribosomes, the presence of hypertrophy of nuclei, and especially nucleoli, which acquired a loosened appearance due to an increase in the filamentous component. Synthesis and secretion of secretory granules in somatotropocytes were slightly higher than in control.

A characteristic feature of the liver of rabbits receiving a recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2), there was a large number of hypertrophied hepatocytes with polyploid nuclei. The cytoplasm of the cells is rich in organelles, a well-defined granular and agranular endoplasmic reticulum, which indicates intense protein synthesis. Most hepatocytes contained 2 or 3 nuclei with well-developed nucleoli, which had a nucleonemic character characteristic of immature (blast) cell forms. Similar changes in the liver of mice were observed with the introduction of STH [Geschwind J., Albert M., Schooley C. The effect of thyroxin and growth hormone on liver poliploidy. Biol. Bull. 1960. V. 117. No. 1. P.56].

The use expressing the formation of somatoliberin strain Lactobacillus sp. 8 times (pLF-SL2) had a statistically significant (P <0.05-0.01) stimulating effect on the growth of the quadriceps femoris. The diameter of muscle fibers and the area of the core after 1, 2 and 3 months of giving the drug, compared with the control, increased by 296%, 45.2%, 21.2% and 54.9%, 48.9% and 33%, respectively . Moreover, in the subcutaneous adipose tissue, a decrease in the diameter of adipocytes by 11.2-15.8% was observed (Table 3).

An increase in the mitotic activity of chondrocytes was observed in the epiphyseal growth plate of the femur of the 3rd group rabbits, and measurement of the tubular bones of the chest and pelvic limbs showed that in animals treated with the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2), they were significantly (P <0.05-0.01) longer than that of peers in the control group.

Thus, studies indicate that the oral use of the recombinant strain of Lactobacillus sp. 8 times (pLF-SL2) provides the same biological effects as the use of exogenous GH, i.e. somatoliberin formed in the intestine after absorption into the blood initiates an increased production of own growth hormone in animals, which leads to an increase in live weight gain, an increase in muscle tissue in meat, and a decrease in fat content.

Example 2. The study of the oral administration of a strain of Laclobacillus sp. 8 TIMES (pLF-SL2) to pregnant rabbits on the immune response of nascent young animals.

To conduct the experiment, two groups of 3 females of each breed in the group were formed from rabbit breeds, Californian and Soviet chinchilla. The animals were covered in one day. Both groups received PR in accordance with the recommended norms. It consisted of hay and compound feed or grain, and in the summer months the hay in the diet was replaced with grass. During pregnancy (30 days), females of the 1st experimental group were fed daily, in addition to OR, 1 ml of a culture containing 2.5 × ^{10 9} K. o / ml of the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) expressing the formation of somatoliberin. The second group of additives did not receive and served as a control. After the rounding, the born rabbits were weighed, and when they reached 45 days of age, the young animals received from the experimental and control groups of rabbits formed 3 groups of 9 animals each. The rabbits from the mothers of the experimental group were divided into the 1st (control), 2nd and 3rd experimental groups. Animals of the control group received OP. In addition to OR, young animals of the 2nd and 3rd groups were fed daily 1 ml of cultures (2.5 × 10 ⁹ cfu / ml) of the initial probiotic strain Lactobacillus sp. 8 times and the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) respectively. From young rabbits born of mothers of the control group, the 4th control, 5th and 6th experimental groups were created, which were fed similarly to the 1st, 2nd and 3rd groups, respectively. Microbial preparations lasted 3 months.

Studies have shown that daily feeding of a recombinant strain to rabbits during pregnancy significantly increased the live weight of the nascent young. Thus, the live weight of rabbits of California and Soviet chinchilla breeds at birth was 65 ± 5 g and 68 ± 4 g in the control, and in the experiment 98 ± 5 g and 90 ± 4 g (P <0.01), i.e. exceeded the young growth of the control groups by 51% and 32%, respectively, or on average by 41%. These data indicate that, after absorption, the somatoliberin formed by the recombinant strain penetrates the blood through the placental and blood-brain barriers and has a specific effect on the hormonal regulation system formed in embryos. Rabbits born to mothers who received a recombinant strain of Lactobacillus sp. 8 times (pLF-SL2), they grew better and at 40 days of age exceeded the live weight of their peers from the control group by 26% (980 g versus 777 g).

Introduction into the diets of post-weaning (45 days) young stock obtained from control females for three months of the initial probiotic and recombinant strains of Lactobacillus sp. increased live weight gain by 2% and 4.4%, while in rabbits born to mothers who were given a recombinant strain, the increase in growth was 4.3% and 14.5% (P <0.01), respectively. The body length and chest girth behind the shoulder blades in animals of the 1st, 2nd and 3rd groups averaged 36 cm and 27.6 cm versus 34.2 cm and 25.5 cm in rabbits of the 4th, 5th and 6th groups. According to the incidence index, rabbits born to mothers fed a recombinant strain and fed it with feed for 3 months, significantly (P <0.05) exceeded the control. In these animals, an increase in blood flow, an increase in the number of mitoses, and an increase in the secretion of granules into the capillaries were noted in the adenohypophysis. In the pancreas, an increase in the number and size of islets of Langerhans was observed, and the diameter of the fibers in muscle tissue increased 1.5 times. In the thymus, lymph nodes and spleen, an increase in the size of the germinal zone of nodules, the appearance of a large number of blast forms of lymphocytes and cluster-forming cells was noted.

Thus, the data obtained indicate that giving pregnant rabbits rabbits expressing the somatoliberin gene of Lactobacillus sp. 8 TIMES (pLF-SL2) induces tolerance to this hormone in nascent young animals.

Example 3. Determination of optimal dosages for the use of the strain of Lactobacillus sp. 8 TIMES (pLF-SL2).

For the experiment, 5 groups of 5 animals each were formed from a 45-day-old young rabbit of the Californian breed. The first group served as a control and received an OP identical to that in Example 2. Rabbits of the 2nd, 3rd, and 4th groups were additionally fed 1 ml of a culture of a recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) (2.5 × 10 ⁹ cfu / head), 0.5 and 1 ml of ten-fold concentrate of this culture (12.5 × 10 ⁹ and 25 × 10 ⁹ c.oe / head), respectively, and animals of the 5th group received a concentrate in a dose of 0.5 ml (12.5 × 10 ⁹ cfu / head) once every three days. The experiment lasted 3 months.

Studies have shown that in the first month of giving the drug, the increase in live weight in rabbits of the 1st and 2nd groups turned out to be the same, while in the 3rd, 4th and 5th groups it exceeded the control by 26; 12.4 and 15.7%, respectively (P <0.05). After 2 months of feeding, the maximum increase in live weight was in animals of the 3rd and 4th groups treated with Lactobacillus sp. 8 times (pLF-SL2) in doses of 12.5 × 10 ⁹ and 25 × l0 ⁹ K.oe per head daily, and exceeded the control by 13.6 and 12%, respectively. In general, for the experiment, the maximum increase in growth (20.8% and 13%) was observed when feeding the drug at a dose of 12.5 × 10 ⁹ cfu on the head daily and once every three days (table. 4).

There were no significant differences between groups in the slaughter yield of carcasses, and it varied within 47.3-50.6%. Boning of carcasses showed that the percentage of muscle tissue from 76.6 in the control increased to 78.5 and 79.3 in rabbits of the 2nd and 3rd groups, and the fat content in them decreased from 6.3% to 3.1 and 3.3%, respectively (table. 4). In the meat of the hind legs, there was a tendency to increase the concentration of protein, and the fat content at high doses (12.5-25.0 × 10 ⁹ cfu / head) of the drug decreased by more than half.

Morphological studies of endocrine glands, organs and tissues, as in examples 1 and 2, revealed their reaction to exogenous somatoliberin.

In neurons of the supraoptic nucleus of the hypothalamus of rabbits receiving a recombinant strain at doses of 2.5-12.5 x ^{10 9} cfu / head daily, signs of increased functional activity were observed. Large “light” neurons with a polygonal or elongated shape, a light, friable, chromatin, vesicular nucleus, a large number of granules in the cytoplasm prevailed, and therefore cells were clearly visible among nerve fibers. In animals that received the drug at a dose of 25 × 10 ⁹ cfu / head, degenerative phenomena of both neurons and nerve endings were noted.

In the adenohypophysis of rabbits receiving the drug at doses of 2.5 × 10 ⁹ and 12.5 × 10 ⁹ cfu / head, an increase in the number of activated somatotropocytes was observed, and the synthesis and secretion of secretory granules were higher than in the control. In animals that were given a culture at a dose of 25x10 ⁹ cfu / head, adenocyte discompletion, cytoplasm swelling, destruction of a small number of cells were observed, which indicates a violation of the structure of the pituitary gland and a decrease in its functional activity.

A significantly larger number of hypertrophied hepatocytes with polyploid nuclei was revealed in the liver of experimental animals. The cytoplasm of the cells is rich in organelles, a well-defined granular and agranular endoplasmic reticulum, which indicates intense protein synthesis.

In rabbits of the control group, the exocrine part of the pancreas consisted of large acinous cells, in which the granules of secretion were visible in the zymogenic zone. The number of pancreatic islets was slightly lower than in the animals of the experimental groups. Rabbits receiving the drug in doses of 2.5 × 10 ⁹ and 12.5 × 10 ⁹ cfu / head exceeded the young growth of the control and 4th groups in the number of B-cells in the island tissue, vascularization of the gland, and the size of the islets and their number, i.e. their insular activity was higher.

In the thymus of experimental rabbits, changes in both cortical and brain matter were noted. An increase in the number of secondary lymphocytes, lymphoblasts, and mitotically dividing cells was observed. In the lymph nodes and spleen, an increase in the size of germination centers was noted, which should be considered as an increase in immune reactivity under the influence of exogenous somatoliberin. In the lymphoid tissue of the cecum of experimental rabbits, there was a 15% increase in the number of young forms of lymphocytes and an increase in the density of the arrangement of cells between nodes. At the same time, the number of plasma and rosette-forming cells increased. These changes in the organs of the immune system indicate its higher functional maturity in experimental animals.

Thus, the data obtained allow us to state that the most effective use of the drug Lactobacillus sp. 8 PAZ (pLF-SL2) in doses of 2.5-12.5 × 10 ⁹ cfu / head daily and at a dose of 12.5 × 10 ⁹ cfu / head once every three days.

Example 4. The study of the effects of the strain of Lactobacillus sp. 8 TIMES (pLF-SL2) for goat milk production.

The experiment was conducted on two groups of goats with 4 heads in each, located at the 3rd month of lactation. It consisted of two periods: preliminary (2 weeks) and main (6 weeks). Groups of analogues in terms of live weight, productivity, age and lactation period were formed at the end of the preliminary period. Animals were kept in individual cages. Goats of the control and experimental groups received the main diet in accordance with existing standards. In the main period of the experiment, the experimental group was fed daily with a mixture of 2.4-2.5 × 10 ¹⁰ cfu / head of the preparation of the strain Lactobacillus sp. 8 TIMES (pLF-SL2).

Studies have shown that during the experiment, the live weight of animals of both groups was practically the same. There was no significant difference in the energy and dry matter intake of the feed between the groups in both periods of the experiment, but the gross consumption of these food ingredients during the experiment decreased both in the control and experimental groups of goats. At the same time, milk production decreased in all animals, however, the use of the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2) slowed down its fall. If the animals of both groups did not differ in the average daily milk yield in the preliminary period and in the first two weeks of the main period, then in the next two-week period of the experiment there was a clear tendency to increase the daily milk yield by 20.2% in goats of the experimental group, and in the last two weeks of the experiment the increase in milk yield became even more contrasting (26.5%) (Table 5). Along with this, the protein content in milk increased. If in animals of the control group its concentration continuously decreased during the experiment, then in goats of the experimental group, after two weeks of using the drug, the decrease in protein concentration in milk stopped, and at the end of the experiment it exceeded that in the control by 11% (P <0.05). Animals that received the microbial preparation better used food for productive purposes. If in the first two weeks of the main period for goats of the experimental group, the increase in milk yield, energy efficiency and dry matter of feed for milk of 4% fat content was still small and varied within 7.2-7.6%, then in the next 4 weeks of the main during the experimental period, these indicators significantly (P <0.05) increased and exceeded the control by 27.2-28.3%, 24-27.4% and 23.4-26.9%, respectively.

Thus, it was found that oral administration of the recombinant strain of Lactobacillus sp. 8 TIMES (pLF-SL2), which expresses the formation of somatoliberin, is an effective way to increase the milk yield and productivity of goats and can be a real alternative to using various somatotropic hormones in animal husbandry.

Claims (4)

1. A method of increasing the productivity of farm animals and improving product quality, comprising the inclusion in the diet of a probiotic preparation containing lactic acid bacteria, characterized in that a recombinant strain of Lactobacillus sp. Is used as a probiotic preparation. 8RAZ (pLF-SL2) expressing somatoliberin in the digestive tract. 2. The method according to claim 1, characterized in that to increase the gain in live weight, increase the proportion of muscle tissue in meat and reduce the fat content, the recombinant strain of Lactobacillus sp. 8RAZ (pLF-SL2) is given in doses of 2.5-12.5 · 10 ⁹ cfu / head daily or in a dose of 12.5 · 10 ⁹ cfu / head once every three days . 3. The method according to claim 1, characterized in that, in order to improve the quality of the products, somatoliberin tolerance is created in the nascent young by including a recombinant strain of Lactobacillus sp. 8RAZ (pLF-SL2) at a dose of 2.5 · 10 ⁹ cfu / head daily. 4. The method according to claim 1, characterized in that to increase the productivity and milk yield of lactating animals, a recombinant strain of Lactobacillus sp. 8PA3 (pLF-SL2) is given in doses of 2.4-2.5 · 10 ¹⁰ cfu / head daily.

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