Direct and maternal genetic variance components for growth traits in red deer (Cervus elaphus scoticus)

The objective of this study was to estimate the direct and maternal genetic variance components for some growth traits in a red deer herd (Cervus elaphus scoticus) located in Queretaro, Mexico. Information between 1994 and 2003, consisting of 417 records of birth weight (BW), 169 weaning weight (WW), 168 six months weight (6MW) and 172 yearly weight (YW) was analyzed, which included the identification of 554 animals with 11 stags and 107 hinds. The fixed effects considered were: sex, year of birth and pregnancy number (P < 0.001). Three mixed models were used. Model 1 included the fixed effects and the direct additive genetic effect; Model 2 included those in 1 plus the maternal additive genetic effect; and Model 3 included those in 2 plus the permanent maternal environment effect. All of them used the residual maximum likelihood method (REML), implemented in the ASReml program. The best model to obtain variance components and genetic parameters was the second model, direct heritability (h(d)(2) +/- s.e.) 0.11 +/- 0.09 and 0.19 +/- 0.18 and maternal (h(m)(2) +/- s.e.) 0.15 +/- 0.06 and 0.14 +/- 0.11 for BW and WW, respectively. The direct-maternal genetic correlations were -0.21 +/- 0.29, -0.92 +/- 0.11 and -0.84 +/- 0.20 for BW, WW and 6MW, respectively.