|
Description:
|
The objective of this study was to identify genotypic differences in different breeds of cattle and to determine their associations with growth , performance and carcass traits . The majority of cattle used in this study were Bos indicus influenced . All the cattle were identified for feedlot and carcass data such as initial weight (IWT ) , final weight (FWT ) , number of days on feed (DOF ) , average daily gain (ADG ) , skeletal mamrity (SM ) , overall maturity (OM ) , lean maturity (LM ) , hot carcass weight (HCW ) , calpastatin gene activity (CAL ) , rib -eye area REA ) , kidney , pelvic and heart fat percentage (KPH ) , marbling score (MRB ) , and Wamer -Bratzler shear force . Blood samples were obtained from all animals to extract genomic DNA . Five candidate genes were investigated for polymorphisms related to performance traits . These genes were Growth Hormone , Insulin -like Growth Factor 1 , Somatostatin , Leptin and Prolactin . Associations between genotypes and performance measured were analyzed through analyses of variance procedures . Genotypic and allelic frequencies were calculated for the prolactin microsatellite marker in animals in the upper 10 % and lower 10 % of the distribution for all traits studied . Genotypes were not able to be determined for Growth Hormone , Insulin -like Growth Factor 1 , Leptin , and Somatostatin . |