EGG PRODUCTION BY QUAILS DEPENDING ON THE LENGTH OF THEIR PHOTO-STIMULATION

Studies to determine the rational length of photo-stimulation of the Japanese quail parent flock (Coturnix japonica) were carried out at a farm in Kiev region. It was found that mating of male and female quails at the earlier age of 4 weeks, has led to an increased mortality of female quails starting with the first month of breeding. In general, for the entire 7-month productive period, the quail safety indicator was the highest in the 2^nd experimental group (90.0%) and in the 3^rd control group (89.2%), in which the mating began at the age of 5 and 6 weeks. In the 1^st experimental group, where the mating of quails began at the earlier age of 4 weeks, the safety was 1.7-2.5% less than in the groups 2 and 3. With regard to the quails egg productivity by each group, it was found that the 10% of eggs were laid at the age of 51-52 days in groups 1 and 2, while in groups 3 and 4 the same indicator was achieved 2-3 days later. However, all groups reached the 50% rate of the egg production intensity at the same age of 62-64 days. The egg production rates for initial and average hens in group 1, where the mating began at the age of 4 weeks, were the lowest and amounted to 124.1 and 133.7 eggs. The most optimal, given the productivity data, was the acquisition of quail parent stock at the age of 5 weeks, which contributed to the achievement of 131.2 and 138.3 eggs rate respectively per initial and average quail hen, which was 7.1 and 4.6 eggs, or 5.7 and 3.4% more than in the 1^st experimental group. Comparing the egg productivity indicators in the 2^nd, 3^rd and 4^th experimental groups, it is worth noting that the acquisition of quail parent stock at the age of 6-7 weeks resulted in a decrease in egg production per initial and average quail hen respectively by 3-3.5 and 2.9-3.4 eggs, or by 2.3-2.7% and 2.1-2.5%, compared to the 2^nd group where the mating began at the age of 5 weeks. It was observed a tendency of increase in the average egg mass to 10.05 g and the total egg mass per average layer during the whole experiment cycle to 1.390 kg in the 2^nd experimental group, compared to other groups. The data obtained give enough grounds to believe that the most favourable for the acquisition of Japanese egg quail parent stock is the age of 5 weeks