Effect of the concentration of estradiol and vitellogenin in the blood serum of meat and egg breed chickens on egg productivity

Abstract

The aim of the research is to determine the effect of changes in the concentration of estradiol-17β on the concentration of vitellogenin at the stage of egg shell formation and preparation of the body of meat and egg breed chickens (for example, the Pushkin breed) for ovulation.Materials and methods. The material for the study was the Pushkin breed chickens, in the amount of 28 heads. at the age of 48 weeks. Chickens were kept in individual cages. Light mode - 14C:10T. Drinking - nipple, temperature in the house and feeding - according to the standards adopted in the bioresource collection of RRIFAGB "Genetic collection of rare and endangered chicken breeds." Within 10 days prior to blood sampling, an ultrasound scan of the ovary and oviduct was performed from the studied group of chickens, which made it possible to determine the stage of egg formation. Blood from the studied chickens was taken in the morning on an empty stomach for the simultaneous determination of the concentration of estradiol and vitellogenin at the stage of egg shell formation. The concentration of estradiol and vitellogenin in the blood plasma of chickens was determined by ELISA. To clarify the effect of the concentration of estradiol (E2) on vitellogenin (VTG), the studied flock was divided into 2 groups according to the concentration of vitellogenin: 1st gr. – > Mav. (> 20 μg / ml) and 2nd gr. – < Mav. (<20 μg / ml). During the study period, eggs of chickens were evaluated according to the following morphometric parameters: the weight of the egg, yolk, protein and shell, elastic deformation, shape index, density of protein fractions, thickness of the shell and subshell, marbling. The number of eggs laid was determined in 10-day trial period.Results. It has been established that the duration of the ovulatory cycle in Pushkin breed chickens is 27-29 hours. As a result of such a long ovulatory cycle in the following days, laying of eggs occurs later with a progressive shift, as a result of which the laying cycle on average for the studied group of chickens is 3 days. The E2 level in the 1st group was 258,48 ± 30,60 pg/ml (p < 0,05), which significantly differed from the 2nd group – 181,45 ± 13,81 pg/ml. A positive correlation was found between VTG and E2, r = 0,5 (p < 0,001).Conclusion. The VTG level significantly increases in Pushkin chickens at the age of 48 weeks with an increase in the concentration of E2 in the blood. A positive correlation was noted between these features. According to the results of our research, the high content of estradiol and vitellogenin in the chickens blood serum did not have a significant effect on egg productivity.