Features of growth and development of egg cross chicken embryos «Lomann Brown»

Purpose: to study morphometric parameters of absolute values of linear and weight body sizes, specific growth rate and relative (allometric) growth of chicken embryos of the «Lohmann Brown» egg cross at different stages of embryogenesis.Materials and methods. The absolute values of linear and weight body sizes of chicken embryos were estimated using morphometric methods. The formula of I. I. Schmalhausen and S. Brody was calculated the specific growth rate of length and body weight of chicken embryos by the formula simple allometry — relative (allometric) growth of body length from body mass.Results. This is manifested in the increase in the specific growth rate of body length of the embryo at 5 days of the late-fetal stage, 8th, 10th, 12th day of the early-fetal stage and specific growth rate of body mass for 6 days of the late-fetal stage of the late-fetal stage, 10-th and 12-th day of the early-fetal stage. At all stages of embryo development, there is a negative allometry of the relative growth rate of the embryo body length, except for 14 days of the mid-fetal stage, where negative isometry was observed (b=-1,000). Higher values of the power coefficient reflecting the slower growth of the embryo in length relative to their body weight, observed in late-fetal stage at 5-6 days (b=0,913-0,995), in early-fetal stage — 10-e (b=0,960) and 12 days (b=0,928), in mid-fetal stage — 13-th (b=0,821) and 15 days (b=0,981) and late-fetal stage — 20 days (b=0,836).Conclusion. New knowledge derived from this study can be applied not only in research, but in the poultry industry to assess the impact of preincubation processing of eggs on the development of embryos and embryonic mortality at different stages of embryogenesis, the definition of normal and abnormal development of embryos, as well as to assess the impact of other factors, artificial incubation on embryo development, hatchability of eggs and safety of poultry.