South African Journal of Animal Science
versão On-line ISSN 2221-4062
versão impressa ISSN 0375-1589
THIRUVENKADAN, A.K. et al. Genetic and non-genetic factors affecting body weight in Tellicherry goats. S. Afr. j. anim. sci. [online]. 2009, vol.39, n.5, pp.107-111. ISSN 2221-4062.
Data on 566 Tellicherry goats, recorded between 1988 and 2007 were used to study the effect of non-genetic factors on body weight and daily gain from birth to 12 months of age. The least-squares means for body weight at birth and at 12 months of age were 2.17 ± 0.03 and 18.78 ± 0.44 kg, respectively. The pre- and post-weaning average daily weight gains were 72.41 ± 1.68 and 37.46 ± 1.49 g, respectively, and the associated growth efficiencies were 3.11 ± 0.08 and 1.34 ± 0.05, respectively. Significant differences associated with the year of kidding were observed in body weight, weight gain and efficiency in weight gain at different stages of growth. Growth rate of kids born between December and February was relatively slower than those born in other months and this can result from seasonal changes and suggests that it is necessary to plan the kidding season rationally by controlling the oestrus and mating time. The kids born as twin had lower birth weight and slower early growth rate than those born as single but had a higher post-weaning growth rate. The heritabilities of different traits were moderate to high, except for birth weight, which was of low heritability. The phenotypic and genetic correlations among the different body weights were positive and low to high in magnitude.
Palavras-chave : Breed; genetics; growth; heritability; live weight; goat.