An association of C/T polymorphism in exon 2 of the bovine insulin-like growth factor 2 gene with meat production traits in Polish Holstein-Friesian cattle

The effect of the insulin-like growth factor 2 (IGF2) gene polymorphism – a g.292C>T transition in exon 2 on feed uptake and conversion, growth rates, and meat production traits in Polish HolsteinFriesian cattle was investigated. A total of 291 young bulls were genotyped using restriction fragment length polymorphism (RFLP-BsrI). Animals were slaughtered at the age of 11 or 15 months and carcass traits were examined. At the age of 11 months the association was shown of the CC genotype with higher cold carcass weight, daily gain and meat content (%) in valuable cuts. At 15 months of age the CC genotype bulls showed higher live body weight, whereas those with the CT genotype had more fat in valuable cuts. The TT genotype bulls appeared to consume more feed (dry matter and protein) and used more feed for maintenance and meat production as compared to the CC genotype. The imprinting status of the IGF2 gene was analysed using cDNA sequencing and RFLP-BsrI. In 15-months-old animals and in foetuses older than two months both IGF2 alleles, maternal and paternal, were equally expressed in liver. In a 2-months-old male foetus the IGF2 mRNA was primarily expressed from the paternal allele.