The effect of laser radiation exposure time on the blood morphological composition and the hatchability of “the White Hubbard” cross chickens embryos has been studied. The incubation eggs have been divided into 5 groups before incubation and exposed to laser irradiation for 20, 30, 40, 50 and 60 seconds. Blood for study has been taken on the 20th day of embryo development by dissecting large vessels of the neck. Counting of the blood cells has been carried out by conventional methods.

The presented work is the result of studying the influence of the nervous type of the Kholmogory breed cows on their milk productivity in a free stall housing system. These studies clearly demonstrate the advisability of selecting cows regarding their types of higher nervous activity. The average milk yield of animals with a balanced, strong and mobile type of higher nervous activity was 21% higher than in other animals which will make it possible to form more productive herds and increase milk production.

The article presents data of ethological monitoring of Ayrshire first lactation cows, which are kept in tied confinement during summer. Breeding cows according to the ethological individuality is accompanied by an increase of milk productivity indicators. Animals with high feeding activity have a 967 kg increase per lactation, compared with animals with low feeding activity. The productivity of active and ultra active cows increases by 15.6 -17,2 %, while the coefficient of lactation stability increases by 5 - 9 %, unlike the productivity of infrapassive animals.

Nitrogen in the sod-podzolic soils is in the minimum and its deficiency, coupled with insufficient and unstable heat regime in the region, reduces the productivity of Northern agrocenoses. On the other hand, excess of nitrogen fertilizers causes an increased mineralization of natural nitric compounds, soil deterioration and weakens natural soil restoration processes.