Selection of young cattle for live weight at birth

The purpose of the studies was to identify the relationship between the live mass of young cattle at birth and the intensity of its growth with subsequent milk productivity. To conduct studies from newborn calves of the Holstein breed, three groups of 30 heads were formed by the method of pair-analogues by linear affiliation, date of birth and productivity of mothers. Calves of the first (control) group had a live weight at birth below 30 kg, calves of the second (experimental) group - from 30 to 40 kg, the third (experimental) group - more than 40 kg. As a result of studies, it was revealed that calves of the third experimental group exceeded the control by 11.1% in terms of living weight at 12 months of age, and calves of the second experimental group - by 5.5%. In the period from 1 to 6 months of age, calves of the third experimental group had absolute and average daily increases 12.2% higher than calves of the control group and 6.9% higher than calves of the second group. The relative increase in calves of the third group during this period was lower than in the control by 8.2% and 3.5% lower than in calves of the second group. A similar trend was observed between 6 and 12 months of age. Calves of the third group reached the age of the first fruitfully insemination 0.8 months earlier than control and 0.2 months earlier than animals of the second group. At the same time, their live weight by this age exceeded the control by 7.7% and by 2% of animals of the second experimental group. Yield for 305 days of lactation in cows that had a live weight at birth of more than 40 kg. higher, which is 6.1% and higher in cows of the control group than in cows with a live birth weight of 30 to 40 kg. 2.2%.