The influence of live weight of holstein cows on the duration and effectiveness of their economic use during the period of breeding

Abstract

There are shown data on the impact of live weight of Holstein cows on the duration and effectiveness of their lifetime use during the period of breeding. It was established that the animals which are not reached to the body breed standard of their weight at some period of age had lower rates and duration of lifetime use and productivity. Animals with live weight at 6 months – 181–220, 12 months – 311–340, 18 months – 411–440, at the first insemination – 411–440 and at first calving – 511–540 kg had the longest life duration, productive use, quantity of lactations during all life and highest lifetime productivity. The highest positive correlation coefficients were established between body weight of cows at different periods of their growth (exception – live weight at first calving) and lifetime milk yield (r = 0.072–0.106), the average lifetime fat milk (r = 0.062–0.126), lifetime quantity of milk fat (r = 0.077–0.112), milk yield per day of life (r = 0.077–0.165) and productive use (r = 0.077–0.112). These links were much weaker between live weight and life duration in the studied ages of animals (r = -0.009 – +0.062), productive use (r=-0.125 – +0.094), lactation (r = -0.093 – +0.038) and the number of lactations during life (r = -0.134 – +0.029). The lowest correlation coefficients were between body weight at first calving of cows and the studied parameters of duration and effectiveness of their lifelong use. The impact of the live weight of animals during growing period on the duration of their economic use was the highest (23.34–31,30%), the number of lactations for life (13.79–28.08%), lifetime milk yield (11.89–15.68%) and lifetime amount of milk fat (11.42–15.16%).