Meta-analysis of average estimates of genetic parameters for growth, reproduction and milk production traits in goats

摘要

A meta-analysis of 84 published reports on goats was conducted to calculate weighted and unweighted average direct heritability (h(a)(2)), maternal genetic effect (h(m)(2)), common environmental effect (c(2)), repeatability (R), genetic (r(g)) and phenotypic (r(p)) correlations for growth, reproduction and milk production traits. Weighted average h(a)(2), h(m)(2), and c(2) for growth traits ranged from 0.03 to 0.45, 0.05 to 0.27, and 0.02 to 0.10, respectively. Weighted average h(a)(2) for reproduction and milk production traits ranged from 0.00 to 0.17 and 0.15 to 0.22, respectively. Weighted R for the growth, reproduction, and milk production traits ranged from -0.06 to 0.56, 0.06 to 0.13, and 0.50 to 0.61, respectively. Weighted averages of r(p) and r(g) among growth traits ranged from 0.06 to 0.84 and 0.01 to 0.98, respectively. Weighted average r(p) among milk production traits ranged from 0.18 to 0.94. In most cases average h(a)(2) and r(g) had higher observed standard deviations compared to the theoretical standard error. The present finding revealed that weighted average h(a)(2), h(m)(2), c(2), R, and r(g) are more reliable for two reasons: estimates of h(a)(2) for some growth traits were more conservative than values from relatively higher number of records and the absence of significant effects of the tested fixed factors on some parameter estimates. However, studies on genetic parameter estimations are required for growth, reproduction, and milk traits in goats.