Development and productive qualities of repair heifers depending on the season of birth

The purpose of the research is to determine the dependence of the development and productive qualities of replacement heifers on the season of their birth. The results of the analysis showed that heifers born at different times of the year differ in live weight at birth, as well as in growth and development. Experimental animals born in autumn and winter, distinguished by the best growth and development, were fruitfully inseminated for the first time at the age of 14 months. In addition, the first-calf heifers of the winter birth season were characterized by a maximum milk production of more than 9100 kg in the first 305 days of lactation. Thus, studies have shown that the birth season has a significant impact on the development and productive qualities of cattle and can be taken into account as an additional selection indicator.