Genetic and non-genetic factors influencing the performance of the West African Dwarf (WAD) goat kept at the Kintampo Goat breeding station of Ghana

Abstract

A study was conducted to analyse the effect of genetic and non-genetic factors influencing the growth performance of the West African Dwarf goat. Breed records of 836 kids born by 259 does, and 8 bucks from 2011 to 2017 at the station were used. Growth performance traits studied were birth weight, weaning weight, 6-month body weight, 9-month body weight, yearling weight, and pre-weaning and post-weaning growth rates. The fixed effects of sex of kid (male or female), season of kidding (major, minor, and dry), year of kidding (2011–2017), and type of birth (single, twins, or triplets) on growth performance were determined. Genetic parameters such as heritability and correlations among the traits were also estimated. The non-genetic data (fixed factors) obtained were analysed using the general linear model procedures of GenStat (Discovery Edition 12). Heritability estimates obtained for the growth traits were 0.45 ± 0.15, 0.57 ± 0.29, 0.04 ± 0.05, 0.74 ± 0.59, 0.49 ± 0.35, 0.55 ± 0.39, and 0.54 ± 0.36, respectively, an indication of high genetic variation existing among the traits (with the exception of 6-month body weight). This could be harnessed and utilized for genetic improvement within the flock. The phenotypic correlation coefficients among the traits ranged from low to high (0.04–0.95), indicating that there is a linear relationship among body traits of the goats which may be caused by either genetic or environmental factors of correlation. The genetic correlations were also medium to high (0.30– 0.96). The general implications are that selection for any of these growth traits in a breed improvement programme would have a considerable simultaneous positive impact on each other. The overall birth weight, weaning weight, 6-month body weight, 9- month body weight, yearling weight, and pre- and post-weaning growth rates obtained were 1.48 kg, 5.35 kg, 6.56 kg, 8.30 kg, 10.00 kg, 32.26 g/day, and 19.39 g/day, respectively. These growth performances were found to be significantly influenced by the non-genetic factors studied. There is therefore the need to factor these in future breed improvement programmes to ensure their success