A NOTE ON HERITABILITY ESTIMATES FOR GROWTH TRAITS IN MALE AND FEMALEROMANOV SHEEP

A total of 1855 records were analysed using restricted maximum likelih ood (REML) techniques to estimate heritabilities separately for males and females lambs on birth weight (BW), weaning weight (WW), 90-day we ight (W90) and average daily gains birth to weaning (C1) and weaning t o 90 days (C2). An animal model including fixed effects of year X seas on, parity, litter size and rearing type; and random effects of direct genetic effect (h2D) and residual was applied. Estimates of h2D for B W were 0.48 (males) and 0.50 (females); for WW 0.35 (males) and 0.22 (females); for W90 0.21 (males) and 0.31 (females); for Cl 0.20 (males ) and 0.25 (females); and for C2 0.18 (males) and 0.29 (females).