The purpose. To determine the effect of low concentrations of α-zearalanol in feed on the reproductive qualities of laying hens. Methods. The study was conducted at the NAAS State poultry research station on hens, eggs, and incubation waste. At the age of 35 weeks, 2 groups (control and experimental) were formed from hens of Birkivska barvysta breed. The first 14 days (age of the herd 35 -36 weeks) birds received standard feed according to age needs. For the next 3 weeks, the birds of the experimental group received compound feed with an admixture of α-zearalanol in the amount of 50 mkg/kg (bird age 37 -39 weeks), while hens and cocks of the control group received standard feed at that period. Poultry safety, egg weight, hatchability of eggs, distribution of waste by incubation periods were assessed. Results. The preservation of the bird during the experiment was 100%. The positive effect of the additive on the weight of eggs in the experimental group of birds was revealed. Evaluation of the results of incubation of eggs of the experimental group in comparison with the control indicates a beneficial effect of adding α-zearalanol to feed. Thus, if before the introduction of the additive the hatchability of eggs in the experimental group was 7.6%, 10.3, and 12.4% lower than the control, then after the introduction -exceeded the control by 0.1 and 4.0%. The increase in egg hatchability was due to the reduction of embryo death in the late stages of incubation, as well as the category of waste «frozen» and «dead». Conclusions. The stimulating effect of α-zearalanol at a concentration of 50 mkg/kg on the reproductive qualities of poultry was revealed. Before the introduction of α-zearalanol in the feed, the hatchability of eggs of the experimental group was 7.6%, 10.3, and 12.4% lower than the control, after the introduction -the hatchability of the experimental group exceeded the control by 0.1 and 4.0%. The reduction of embryo death in the late stages of incubation under the influence of α-zearalanol deserves an in-depth study and has significant theoretical and practical significance.

The purpose. To determine morpho-functional features of embryonic development of hens at application of covering «Artificial cuticula». Methods. Study of features of embryonic development of hens was carried out by morphometric researches of the dissected germs from control and test groups. At daily chickens they determined mass and length of body. Results. Features of embryonic development of hens are studied at application of covering «Artificial cuticula». Conclusions. Application of covering «Artificial cuticula» before incubation of eggs promotes acceleration of rate of development of embryos during embryogenesis.