Highdem and for eggs requires a significant increase in production volumes subject to the standards of their quality. One of the components of the egg providing its safety and quality is the shell, which accounts for about 10-12% mass of the egg. The formation of eggs in chickens is a complex process, which is carried out within 24-27 hours, from which about 17-20 hours is given to form the shell. Since the main number of eggs chickens are demolished in the first half of the day, most of the calcification period of the egg shel falls on the dark period of day when the chicken stops to eat. A study was conducted to in vestigate the influence of an increased dose of calcium in the form of limestone particles when feeding it in the afternoon on the productivity and quality of chicken eggs. For this, two groups of laying-hens were formed, the mix feed for which consisted of the same components of cereal and protein-vitamin feeds, but was distingueished by calcium content, namely: in the control group in the mix feed, which was fed both in the morning and in the afternoon, was 3,5% calcium in the form of limestone thin and coarse grinding. The chickens of the experimental group in the morning were fed by mix feed with a calcium content of 1.5%, and in the afternoon - with a calcium content of 7% in the form of coarse limestone. Based on the research, it was found that during the 30-week period of productivity, the survival of chickens in the experimental groups was the same. Chickens of the experimental group reached 95% egg production at the age of 186 days, which his 5 days before the control group. Egg production on the middle and initial laying-hens in the experimental group for the whole production period was 178,4 eggs and 173,3 eggs, which is 6,2 and 7,0 eggs more than in the control group. The feeding of the chickens of the experimental group in the afternoon of mix feeds with an elevated calcium content contributed to an increase in the mass of eggs by 1,7 g, the exit of the egg mass on the middle and the initial laying-hens on 0,66 and 0,7 kg, the number of food eggs categories XL and L on 0,5 and 5.4%, compared with the control group of chickens, which was fed both in the morning and in the afternoon, a mix feed containing 3,5% calcium in the form of limestone thin and coarse grinding.

Key words: laying-hens, mix feed, calcium, egg production, eggs mass, eggs quality.