Estimation Of Genetic Parameters Of Production Traits And Growth Rules Of Tianfu Goat

The breeding data from 1999 to 2006 of nuclear breeding farm of Tianfu goat was used for this study. The effect of sex and birth type on birth weight, weaning weight, the weight of different months and the average daily gain (ADG) of different period before and after weaning were analyzed by using LSMEAN; the genetic parameters for these eleve traits were estimated by using MTDFREML. Simultaneously, the growth rules of Tianfu goat were studied using the program of SAS 8.1.The results of the MTDFREML showed that the estimate of heritability about the weight at the age of 18 months (W₁₈) for Tianfu goat was 0.72, which was the highest of all the traits, and the estimates of heritability about weight at birth (Wo), 1 months (W₁), 2 months (W₂), 12 months (W₁₂) and adult goats (W_A) were 0.53, 0.54, 0.45 0.49 and 0.28 respectively, which were middle heritable characters, and the estimates of the average daily gain of weaning goats (ADG₁) was 0.16, which was low heritable character. The genetic correlations between the weight at different ages for Tianfu goat especially that between the weights before 4 months were high, and the phenotypic correlations were high too. This was beneficial to selection in the earlier period of Tianfu goat. However, the genetic correlations between W₁₈ and the weight at other months were low, but the phenotypic correlations were high.The heritability of the litter number was 0.24. The genetic correlations between the litter number and the birth weight and lmonth were -0.74 and -0.55 respectively. The genetic correlation between the number of sibs and the average daily gain before weaning was -0.34. The phenotypic correlation and the genetic correlation between the birth weight...