Maternal heritability and repeatability for litter traits in rabbits in a humid tropical environment

Abstract

Data on litter production traits of does, involving 1120 litters, was collected over a 10-year period (1984 to 1994) and analyzed to estimate heritability and repeatability. Locally adapted does and bucks of predominantly New Zealand White breeding were involved. Traits studied were total litter size born and born alive, and litter size and weight at 21 days, 28 days (weaning) and 84 days (marketing). A doe repeatability model was employed which included a fixed contemporary environmental group effect (year–season–doe parity) and litter size at the corresponding age as a linear covariate (for litter weight traits only), and random animal (additive maternal genetic), permanent (non-additive maternal genetic plus permanent environmental), service sire, and residual effects. Heritability (repeatability) estimates for total litter size born and born alive, and litter size at 21 days, 28 days, and 84 days were 0.09, 0.12, 0.06, 0.09, and 0.07 (0.30, 0.32, 0.26, 0.25, and 0.19), respectively. For litter weight at 21 days, 28 days, and 84 days, heritability (repeatability) estimates were 0.08, 0.09, and 0.02 (0.18, 0.19, and 0.09), respectively. In conclusion, litter production traits tended to be lowly heritable and lowly to moderately repeatable.