Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học Journal of Biology đề tài: Genetic and phenotypic relationships between physiological traits and performance test traits in sheep ND | Genet Sei Evol 1994 26 137-150 Elsevier INRA 137 Original article Genetic and phenotypic relationships between physiological traits and performance test traits in sheep ND Cameron E Cienfuegos-Rivas AFRC Roslin Institute Edinburgh Roslin Midlothian EH25 9PS UK Received 3 November 1992 accepted 12 November 1993 Summary - Genetic and phenotypic relationships between physiological traits and performance test traits were estimated with data from lines of Texel-Oxford sheep divergently selected for carcass lean content for the identification of physiological predictors of genetic merit for carcass lean content. At the end of the performance test blood samples were taken from 151 animals the progeny of 31 sires when fed and when fasted for 30 and 54 h. Heritability estimates for traits associated with protein metabolism creatinine urea and insulin-like growth factor-1 IGF-1 were higher with ad-libitum feeding than heritabilities of traits associated with lipid and energy metabolism 3-hydroxybutyrate non-esterified fatty acids triglyceride and glucose. Several physiological traits 3-hydroxybutyrate creatinine and insulin-like growth factor-1 IGF-1 were moderately correlated with the performance test traits of liveweight and muscle depth but only urea and insulin-like growth factor-1 were significantly correlated with backfat depth. Correlations between physiological traits and predicted carcass composition were estimated as animals were required for breeding or were allocated to another experiment. Based on phenotypic correlations -hydroxybutyrate and IGF-1 may be useful indicators of merit for predicted carcass lean weight with urea being an indicator of predicted carcass lean content. Measurement of physiological traits when animals were fasted may not be required for the prediction of genetic merit using physiological traits as genetic correlations between feeding and fasting were high in absolute value for all physiological traits except glucose. sheep genetic .
