Genetic parameters for body weight, fleece weight and fibre diameter in South African Angora goats
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Snyman, M.A. and Olivier, J.J. 1996. Genetic parameters for body weight, fleece weight and fibre diameter in South African Angora goats. Livestock Production Science 47(1): 1-6.
Permanent link to this item: http://hdl.handle.net/10568/66747
Data obtained through the Angora goat perfornance testing pilot scheme, run by the Department of Agriculture at the Grootfontein Agricultural Development Institute, were analyzed. Data of kids born from 1990 until 1993 in 17 studs were used in the analysis. Traits analyzed were body weight (BW; n = 6240), greasy fleece weight (FW; n = 6239) and mean fibre diameter (FD; n = 6195). Heritability estimates were obtained for each trait employing REML-procedures under univariate animal models. By ignoring or including maternal genetic or environmental effects, four different models of analysis were fitted for each trait. Log likelihood ratio tests indicated that the model including a direct as well as a maternal genetic effect was the most suitable model for all traits. For the estimation of correlations between traits, bivariate analysis was carried out fitting direct effects only. Direct heritability estimates for BW [0.292 (with SE 0.047)] and FD [0.257 (0.046)] were higher than that estimated for FW [0.192 (0.038)]. Maternal heritability estimates of 0.090 (0.071), 0.049 (0.075) and 0.083 (0.068) were obtained for BW, FW and FD, respectively. Positive phenotypic correlations were obtained between BW and FW [0.572 (0.010)], BW and FD [0.548 (0.010)] and FW and FD [0.568 (0.010)]. Estimates of genetic correlations were 0.668 (0.058) between BW and FW; 0.558 (0.057) between BW and FD and 0.551 (0.068) between FW und FD.