The effect of immunogenetic factors on productive longevity and reproductive qualities of cows

Abstract

Increasing the productive longevity of cows with high reproductive ability is an urgent task in dairy cattle breeding both in Russia and foreign countries. Research was conducted in Krasnoyarsk region. The object was retired cows (n = 484). The blood groups of cows, indicators of productive longevity, and reproductive ability of cows were studied. The number of antigen carriers and non-carriers (frequency 30.0% and more) was analyzed. Out of 21 antigens with a frequency of more than 30.0%, the most frequently encountered antigens were E (80.6%), H` (77.5%), L (58.5%), W (57.6 %), A2 (57.0%), Z (54.1%), C (52.5%) and X2 (50.4%). The cows carrying O1 antigen had the highest productive longevity, – the difference from the cows not carrying this antigen by the retirement and lactation age was 0.8 years (p <0.001), and the period of economic use was 9.5 months (p <0.001), life-long milk yield was 3852 kg (p <0.001). Cows carrying antigens G3, O1, and L` had the best reproductive ability. In carriers of antigens O1, G3, and E`3, the service period was lower by 22.9; 20.3 and 18.9 days (p <0.05), and the fertility index was higher by 1.8; 1.6 and 1.7 units (p <0.05). In cows carrying L` antigen, the service period was shorter by 16.9 days (p <0.05).