Совершенствование бестужевского скота с использованием генофонда голштинской и айрширской пород

The paper presents the results of the use of genofond of Holstein and Ayrshire breeds for Bestuzhev cattle improvement. It was established that milk production of mongrel cows in the first lactation, depending on the Holstein breed degree, was more by 356-868 kg of milk than the purebred Bestuzhev breed herd-mates in the same feeding and maintenance conditions (PHolstein breed bloodlines 62,5 75. For the second lactation the difference in milk yield in favour of crossbred animals was 301-743 kg of milk (12,0-29,7%; PAyrshire breed were characterized by increased fat content of milk (+0,14%, Pgenotypes, with the exception of three-bred (BxAxKPG), lost on this basis to Bestuzhev breed herd-mates by 0,04-0,12% (Pgenotypes of animals on the first fawning varied in the range of 28.9-38,8 months. It was optimal for half-bred with Ayrshire breed hybrids. All other genotypes, including pure-bred herd-mates, had higher than the optimal index. Intergroup differences in the duration of calving interval were not detected, it ranged from 11,8 to 12,1 months. Hybrids 1/2B+1/2A were characterized by good fertility, the fertility index was higher than that of Bestuzhev's herd-mates by 5.8 units (Pbreeding in agricultural production cooperative «Volga» has shown that Bestuzhev herd-mates, depending on the age, have consumed1,33... 1,52 food units per 1 kg of produced milk, and Bestuzhev -Holstein and Bestuzhev Ayrshire cows -1,09.1,32 food units, or by 15,1.22% less. Additional annual economic effect from realization of milk of Bestuzhev-Holstein hybrids per head amounted 5268...15190, and from the use of Ayrshire and three-bred hybrids 5600...10640 rubles.