Genetic parameters estimation and animal model ranking for cold carcass mass using Sp statistic in goat.

Full Length Research Paper. It is also available at : http://www.peakjournals.org/sub-journals-PJAS.htmlGenetic parameters for simple carcass traits in developing countries where goats are numerous are scarce. Variance components for additive direct, additive maternal, permanent environmental maternal effects, the covariance between additive direct and maternal effects were estimated by restricted maximum likelihood, fitting six animal models from 2341 cold carcass mass pedigree records of indigenous Matebele goat of Zimbabwe. All investigated models included a random direct genetic effect, but different combinations of random maternal genetic and permanent environmental effects as well as direct-maternal genetic covariance. The direct heritability (h2a) ranged from 0.05 to 0.25 when the maternal genetic effects were included in the model, whereas h2a estimates were 0.06 and 0.26 when maternal effects were excluded. The maternal heritability (h2m) was 0.00 when only maternal genetic effects were included in the model and were 0.05 and 0.10 when the permanent environmental effect of the dam was added. The permanent environmental effect of the dam was negligible and, both positive and negative co variances between direct and maternal genetic effects (?2am) were observed. Using Sp statistic Model 5 which had all the random effects, and a covariance fitted proved to be the ?best? among the six models