Probiotic drug based on Kluyveromyces marxianus for poultry

. The article provides an analysis of the relevance of the use of yeast probiotic drugs, their use in agriculture is considered. The results of practical studies on the effect of a probiotic drug based on kluyveromyces marxianus on the productive indicators of laying hens are presented. The article presents data reflecting the indicators of the productive qualities of laying hens, on the basis of which the conclusions confirming the effectiveness of the use of a probiotic drug based on kluyveromyces marxianus in egg poultry farming are summarised and presented.


Introduction
The introduction of probiotics in such industries as poultry, pig breeding, cattle breeding is taking place in all countries of the world today.It has been found that in many cases they are able to reduce the use of enzymes, amino acids and vitamins in animal rearing.Probiotic-based products are actively used in the field of animal hygiene, grain and succulent feed preservation, biotechnological synthesis of components for the feed industry.The animal body is an open system into which transit microorganisms (proteus, klebsiella, enterobacteria, pathogenic clostridia and E. coli, staphylococci, etc.) enter.Against the background of weakened immunity, these microorganisms can multiply and displace normal microflora and cause a number of diseases.Therefore, measures to "populate" the digestive tract of animals and poultry with probiotics can reduce the use of expensive drugs, stimulate the natural resistance of animals, and even significantly reduce the use of antibiotics [1][2][3][4].
In recent years, there has been a growing interest in new yeasts with potentially probiotic properties.New isolates have been isolated from various products and the environment, such as fruits and vegetables, fermented food and beverages, industrial dairy waste, etc.New isolates must have all the properties necessary for the probiotic strain, meet safety requirements and have good production properties.Isolation of various species from numerous media allows the discovery of new strains of probiotics with innovative biochemical properties, for example, the ability to secrete lactase extracellularly, which may give additional ability to digest serum used as a food additive in animal feed [5][6][7][8][9][10][11][12][13].
Recent studies indicate that in addition to S. cerevisiae var.boulardii other species have probiotic properties, for example, Kluyveromyces marxianus.
Several yeasts, which are eukaryotic microorganisms, have long been used in various industries because of their potential applications, both for fermentation and for the production of specific metabolites [14][15][16][17][18][19][20][21][22][23].Kluyveromyces marxianus is one of the most favorable non-traditional yeasts, usually isolated from a wide range of natural habitats, such as fermented traditional dairy products, kefir grains, sugar industry wastewater, sisal leaves and plants.These are nutritional yeasts with various beneficial properties, such as fast growth rate and heat resistance, which make them attractive for various industrial food and biotechnological applications.K. marxianus is a respiratory-fermenting yeast capable of producing energy either by respiration or by fermentation.It produces a wide range of specific metabolites and can contribute to various food biotechnological and agricultural industries.

Materials and methods
The study of the effect of the probiotic drug was carried out on the basis of the scientific and practical laboratory of poultry farming of the Belgorod State Agrarian University.A probiotic preparation of the drug based on kluyveromyces marxianus has been added to the diets of laying hens.For the experiment, laying hens were divided into 3 groups of 330 heads each.The experiment lasted 28 days.
The parameters of the microclimate, planting density, feeding and watering front were similar for all groups of poultry and corresponded to the normative indicators.The peculiarities of feeding broiler chickens were as follows: the control group received only the main diet; experimental 1 received 100 g of the drug per ton of water in addition to the main diet; experimental 2 received 20 g / ton of water in addition to the main diet.During the experiment, the following indicators were determined: microclimate data in the poultry house (daily) (temperature, humidity, ventilation parameters in m3/h per head, illumination); accounting for the distribution of feed (daily); accounting for diseases / waste / death (daily); egg production, egg weight (by periods).

Results
The body reacts to the effects of environmental factors depending on its adaptive capabilities.At the same time, the specificity of adaptive reactions depends on the initial functional state, the period of adaptation, etc.When a probiotic preparation based on kluyveromyces marxianus is added to the diet of laying hens, positive changes occur in the poultry body (in terms of productivity and health of the bird), as evidenced by the data presented below.
It is known that the conditions of feeding and maintenance affect the quantity of products produced and the safety of livestock.The dynamics of the number of laying hens during the trial period is presented in Table 1.As can be seen from the data in the table, at the beginning of the experiment, the population of each group was 330 individuals.The percentage of bird safety at the end of the experiment revealed differences in the experimental and control groups.The safety of the control group (without the addition of a probiotic drug to the diet) was 98.5% (325 live individuals), in the first experimental and second experimental groups, the safety was 99.1% (327 live individuals).
The evaluation of the productivity of the control and experimental groups of poultry was carried out in a complex, according to several parameters at once: the estimate of the number of eggs per day at the beginning and end of the experiment; egg production; the average weight of 1 egg at the beginning and at the end of the experiment.The data obtained are presented in Tables 2, 3, 4. On the first day of the experiment, the number of eggs (in 24 hours) in all experimental groups it was about the same: 268 pieces in the control group, 269 pieces in the first experimental group and 266 pieces, respectively.The check on the 14 th day showed significant differences in the control group, in which the minimum result was recorded: 265 pieces, and higher indicators of the first and second experimental groups of 281 and 274 pieces, respectively.By the end of the experiment, this dynamics remained: the minimum result was 269 eggs and higher indicators of the first experimental group, 291 pieces (8.2% more than the indicator of the control group) and 277 (3% more than the indicator of the experimental group) pieces in the second experimental group.
The productivity of laying hens in terms of egg production is presented in Table 3.As can be seen from the data presented above, the egg-laying indicators at the landing of the bird were approximately at the same level.In the middle of the experiment, the egg production of the first and second experimental groups was 85.7% and 83.5%, respectively, and the egg production of the control group almost did not change.By the end of the experiment, the egg production of the first and second experimental groups was 6.2% and 1.9% higher than the indicator of the control group above the indicator of the control group.During the study period, differences in the average egg weight of the experimental and control groups were revealed.Both on the 14 th day and on the 28 th day of the experiment, an increase in egg weight was detected only in the first experimental group.By the end of the experiment, it turned out that the average egg weight in the first experimental group had increased by 2.2%, compared with the control and second experimental groups.
Laboratory studies revealed that according to all the studied indicators (shell thickness, vitamines A, E, carotene) remained at the same level in all groups.

Table 1 .
Productivity of laying hens (by the number of eggs at the beginning and end of the experiment).

Table 2 .
Productivity of laying hens (by the number of eggs at the beginning and end of the experiment).

Table 4 .
Productivity of laying hens (by mass of an egg, g).