Variance components of early growth traits in the Boer goat
Variance components and resulting heritabilities of birth weight (BW), weaning weight (WW), preweaning average daily gain (ADG), 6 months weight (6 mW), 9 months weight (9 mW), yearling weight (YW) and the preweaning Kleiber ratio (KR) were estimated in either or in both of two Boer goat herds at two different locations (A and O), using the derivative-free restricted maximum likelihood (DFREML) procedure. Direct heritabilities (h2a of Model 1) were estimated as 0.33 and 0.36 (BW), 0.27 and 0.60 (WW) for herds A and O, respectively. For ADG and the KR heritabilities of, respectively, 0.26 and 0.21, were found for herd A. Heritabilities for 6 mW, 9 mW and YW in herd O, were 0.60, 0.40 and 0.36, respectively. When using Model 5, direct heritabilities (h2a) were 0.16, 0.18, 0.17 and 0.11 in herd A for BW, WW, ADG and KR, respectively. The genetic correlations between direct and maternal influences (rgam) were negative for BW and WW (-0.31 and -0.15), but zero for ADG and positive for KR (0.50). It was concluded that the maternal component should be taken into account in the selection of Boer goat females. © 1997 Elsevier Science B.V.