The effect of genotypic variants of growth hormone on growth performances in Podolica and Charolais young bulls

Growth hormone gene was examined as a candidate gene because of its essential role on growth processes becoming a perfect candidate marker associated with somatotropic axis The aim of this work were to assess the genetic variability in young bulls of Charolais and Podolica breed, traditionally reared for meat production and to study the relationship between GH-AluI polymorphism and growth performance traits Blood samples for DNA genotyping were obtained from 22 Charolais and 48 Podolica unrelated bulls belonging to different farms located in Southern Italy Animals were genotyped for the Leu/Val polymorphism in the OH gene Allelic frequencies of L and V were 0 72 and 028 and 0 85 and 0 15 respectively for Charolais and Podolica bulls The weights were measured at different age (W180, W270 and W360) and average daily gains (ADG) were calculated in three different periods (ADG180-270 ADG270-360 and ADG180-360) Charolais LL homozygotes had higher live weights (248 47 kg, 368 13 kg, 490 46 kg vs 243 50 kg, 360 28 kg and 479 88 kg) compared to the LV heterozygotes, Podolica LV heterozygotes had higher live weights (219 45 kg vs 217 54 kg) compared to the LL homozygotes only in the first 180days while at the last check (BW360) the LL showed the higher live weight (323 96 kg vs 321 96 kg), nevertheless all these differences were found not significant Finally ADO was higher in the Charolais and Podolica LL animals compared to the LV bulls