Influence of genotypical and paratypical factors on the productivity of dairy cattle

Abstract

Goal. To study the effect of the genotype of the parents and of parameters of microclimate on the productivity of dairy cattle. Methods. Analysis of experimental studies on the application of effective methods of selection, the study of the environment, assessment of productive qualities of animals for growing in various types of buildings. Results. The formation of the genetic potential of dairy breeds was made according to the breeding value of pedigree bulls. The share of influence of the bull based on «hope» is 16.4–34.5%, and on the fat content in the milk — 15.3–20.1% (P<0.001). One of the many factors influencing the productivity of agricultural animals is the parameter of the microclimate in the building where they are kept. In the cold period of the year the most problematic in terms of comfort there are periods of prolonged cold. In loose housing of cows, the decrease of milk yield because of frosts reached 1.5 kg per day. The strength of the influence of the temperature and the velocity of the air in the general phenotypical variability in the level of milk yield and yield of milk fat over the lactation into account respectively made 33.6 (P<0.001), 29.4 (P<0.05), 35.3 (P<0.001), and 28.3% (P<0.05) respectively. It is established that to improve the profitability of livestock breeding the microclimate in the building requires significant improvements in the winter-summer period of the year at the natural ventilation system. Conclusions. Quantitative and qualitative indicators of milk productivity of cows of native breeds are determined by breeding value and linear membership of bulls, used for the reproduction of breeding stock. A favorable climate should be considered as an important factor of the realization of genetic potentialities of dairy cattle at pure breeding.