Genetic and phenotypic parameter estimates for growth and conformation traits in guineafowl

Mundra, B. L.; Raheja, K. L.; Singh, H.

Multitrait maximum likelihood procedure was used to estimate heritabilities for body weight and conformation traits, genetic and phenotypic correlations among these traits. Data taken from 6309 guineafowls (progeny of 116 sires) produced in 18 hatches during 1987 through 1989 at Central Avian Research Institute, Izatnagar, were used. Analysis was carried out by a mixed model containing hatch and year as fixed effects and sires within year as random effect. Paternal half sib heritability estimates for body weight at various ages unadjusted for full sib relationship ranged from 0.28 +- 0.11 to 0.58 +- 10. The heritability of shank length at 8, 12 and 16 weeks were 0.25 +- 0.14, 0.34 +- 0.19 and 0.24 +- 0.13 respectively. Corresponding estimates for keel length were 0.27 +- 0.16, 0.32 +- 0.20 and 0.03 +- 0.12, respectively. Estimates of heritability of breast angle at 12 and 16 weeks were 0.23 +- 0.16 and 0.30 +- 0.18 respectively. Heritability estimates of the traits adjusted for fullsib relationship were 13 to 28% lower than the unadjusted heritability. These results suggest that heritability obtained from halfsib correlation method ignoring dam effect into the model need to be adjusted for full sib relationship. Genetic and phenotypic correlations among body weights at various ages were high and positive. Similarly, genetic and phenotypic correlations between body weights and conformation traits were positive and high. Moderate to high heritability of 4- and 12-week body weight and high genetic association between these two traits suggested that selection to breed guinea fowl for heavy market weight can effective be made in two stages, first on the basis of 4-week body weight and secondly on the basis of 12-week body weight.