According to the opinion of F. Z. Meyerson, one of the main reasons for disruption of organs' plastic functions under stress is insufficient intake of substrates and cofactors required for synthesis of nucleic acids and protein, as well as partial or complete fasting. In the first stage, according to the author, activity of amino acids’ gluconeogenesis and transamination enzymes increases through the neurohumoral effect, which is the reason of reduced synthesis of protein and transformation of amino acids into glucose, i.e. plastic resources of the organism, its structural proteins, and energy resources in particular, are transformed.

The use of probiotics Levisel SB Plus and Cellobacterin-T in the amount of 0.50 kg/t of mixed fodder in the diet of young herd replacement of the meat direction during the growing period from 3 to 45 days allowed to get homogeneity by 20.9 and 13.1 % above the analogues of the control group. Probiotic feed additive Levisel SB Plus increased the number of fertilized eggs by 1.96 %, hatchability – by 0.90 %, hatchery waste decreased by 2.7 %, feed costs decreased by 9.6 %. However, the best production results were shown by the group with a similar rate of probiotic Cellobacterin-T introduction, which had these indicators, respectively, of 2.0 %, 1.28, 4.2 and 10.4 %.

Occasional use of the probiotics Levisel SB Plus and Tsellobacterin – T in a dose 0.50 kg/t of the mixed fodder in a diet of the laying hens at the age 21-26, 34-39 и 45-48 weeks has increased metabolic processes in the body of a bird and productivity of the laying hens in a group with Levisel SB Plus by 10.6 %, with a dash Tsellobacterin – T – by 16.1 %, but it did not affect the weight of the egg during all periods of the productive cycle. The egg incubation results showed that probiotice Levisel SB Plus increased egg hatability by 4.1%, Tsellobacterin-T by 6.2%, their fertilization by 2.1 and 4.2%, the withdrawal of young chickens by 3.5% and 5.1%. The addition of probiotics did not change the hatchability of eggs (93.22 and 93.17%) in these groups, but reduced the amount of unfertilized eggs by 1.8 and 10.3%. There was a higher content of carotenoids and vitamin A in the eggs of the laying hens and in the body of daily chickens. Using the probiotics in the diet of laying hens of the parent herd has reduced the cost of feeding for 10 eggs by 8.2-8.5% , with a dash of Levisel SB Plus by 15,0-15,4%, with a dash of Tsellobacterin – T to the weight of the egg by 1,8-9,7% and 15.3-15.5% respectively. At the same time, the payment of food products increased in the group using Levisel SB Plus by 10.3-10.7%, with Tsellobacterine - T by 20.9- 21.7%, the profitability of production increased by 13.1 and 22.3%.

The purpose of the research was to study the growth and development of the replacement young chickens of the parent herd of meat production and compare the eff ectiveness of the use of two complex feed additives Sorbitox and Probitox. When rearing the replacement young chickens of the cross Ross-308, the use of feed additive Sorbitox at a dose of 0,50 kg/t of feed made it possible to obtain in comparison with the control group the livability of livestock higher by 1,5 abs.%, with a similar dosage of Probitox additive by 2,1 abs.%. Analysis of the causes of culling of the replacement young chickens showed that the use of Sorbitox and Probitox additives reduced culling after two weeks of age, while in the control group it was observed throughout the entire rearing period. The average live weight of poultry of the control and experimental groups at 18 weeks of age had no signifi cant diff erences, but at the same time the uniformity of the group with Probitox additive exceeded the control by 8,7 abs.%, with Sorbitox by 5,3 abs.%. Analysis of the development of the main organs and departments of the gastrointestinal tract showed that the studied feed additives stimulated the development of the liver, heart, muscular stomach, intestines. The weight of the ovary and the length of the oviducts in the group of chickens receiving Sorbitox exceeded the control group by 20,3 and 9,7 %, with Probitox the diff erence was 27,8 and 11,4 %. Feed additives of sorption and probiotic action in the body of poultry stimulated metabolism of an anabolic nature. In the blood of the chickens receiving Sorbitox, the total protein was by 4,5 % higher than the control group, with Probitox by 5,6 %. At the same time, the level of urea decreased by 26,0 and 33,1 %. The highest glucose content was in the blood of poultry receiving Probitox additive (12,5 mmol/l), which exceeded the control group by 20,7 %, in the group with Sorbitox the diff erence was 7,3 %. The tested feed additives contributed to a greater retention of calcium in the poultry body, and also reduced expenditures of feed for rearing replacement young chickens. The use of Sorbitox additive reduced expenditures of feed by 6,9 %, and Probitox by 12,8 %.

No abstract