Influence of genetic and paratypical factors on productive traits and causes of culling of dairy cattle

Improving the efficiency of dairy cattle breeding is impossible without a comprehensive consideration of both genetic and paratypic factors that shape the level of milk productivity, milk quality, disease resistance and, ultimately, the productive longevity of cows. Onesided selection for milk yield without taking into account resistance to mastitis, udder and limb exterior, seasonal, climatic and technological factors inevitably leads to an increase in culling and economic losses. The review includes nineteen works (based on data from different regions of the Russian Federation and adjacent territories), covering breed-linear differences, heritability of key traits and the contribution of controlled environmental factors - from microclimate and diet to the age of first insemination/ calving and the service period.