Features of pubertas of young egg chickens when grown under monochromatic and white lighting

Abstract

The work was carried out in the Amur region at the Belogorsk poultry farm. In the period from 2015 to 2019, five experiments were carried out taking into account the seasonality. The aim of the study was to identify the influence of the spectral composition of light sources on the pubertation of replacement young egg chickens at the age of 15 weeks: the development of the pineal gland, pituitary gland and genital organs of the youngs. The study on replacement young egg crosses of Hisex White and Decalb White chickens was carried out. In the breeding workshop, four groups of day-old chickens were formed, 200 heads each. From one day of age to 15 weeks, young birds were kept under light of different colors in conditions of gradually decreasing daylight hours from 24 to 12 hours a day and an illumination level from 50-30 to 7-6 lux. White, yellow, green and blue compact fluorescent lamps were used as light sources. In young birds at the age of 30, 60 and 90 days, the live weight was determined by weighing 100 heads from each group. A 15-week-old bird was bled for β-estradiol content at a random selection of 30 birds from each group. For anatomical examination, 5 pullets from each group were sacrificed at the age of 15 weeks, taking into account the body weight required by the norm. The absolute mass of the pineal gland, pituitary gland, ovary, oviduct was determined in the bird, the length of the oviduct was measured. Regardless of the season of the year, the live weight of 90-day-old young in groups under white and yellow illumination had the upper values of the norm, with green and blue it could be at its lower border. Under white and yellow illumination, pullets at 15 weeks of age have higher serum β-estradiol levels. At anatomical examination in 15-week-old chickens under white and yellow lamps, the absolute mass of the pineal gland is less by 10.5 - 41.7% than under green and blue ones, and the mass of the pituitary gland, on the contrary, is more by 4.8 - 8.3%. Pullets with different color illumination did not have significant differences in the mass of the ovary and oviduct, as well as the length of the oviduct, the level of development of which corresponded to a given age. Under white and yellow lighting, the first signs of the onset of puberty at 15 weeks of age are slightly more pronounced than under green and blue light sources.