Effect of polymorphism in IGF-1 gene on production traits in Polish Holstein-Friesian cattle.

Abstract

Associations were studied between IGF-1 gene polymorphism and selected beef and milk production traits in Polish Holstein-Friesian (HF) cattle. The IGF-1 genotype was determined in a total of 662 HF cows, heifers and bulls. In month 8 of life, on 213 young animals of both sexes the 28-days feed intake and conversion test was conducted. Moreover, growth rate and beef production traits were determined on 131 HF bulls slaughtered at the age of 15 months. Referring to IGF-1 genotype also milk production traits were studied using performance data of 262 HF cows. Significant differences were found between IGF-1 genotypes in feed intake and feed conversion for growth. Animals carrying genotype BB consumed less dry matter, crude protein and energy per 1 kg body live weight gain than those of AA and AB genotypes. Moreover, the BB genotype appeared favourable for live weight gain during the test. The AB genotype was found positively associated with live body weight at slaughter, cold carcass weight, as well as weight of meat and fat in valuable cuts. Cows carrying AB genotype yielded daily more FCM and VCM milk and more milk fat and milk protein than those of AA and BB genotypes.