Genetic Parameters for Pre-Weaning Litter Traits in Heterogeneous Population of Rabbits (Oryctolagus cuniculus) Raised in the Humid Tropics

Abstract

Data from 302 progeny in a heterogeneous population of rabbits were used to estimate the heritability and correlations (phenotypic and genetic) of pre-weaning litter traits (litter size at birth LSB, litter size at weaning LSW, litter weight birth LWB, litter weight at weaning LWW, kit weight birth KWB, and kit weight weaning KWW). Heritability estimates for litter size ranged from 0.16 (LSW) to 0.22 (LSB). LWB and LWW were more highly heritable (0.52 and 0.55 respectively) than KWB and KWW (0.36 and 0.25 respectively). The genetic (rG ) and phenotypic (rP) correlations between litter size and litter weight at birth and weaning were 0.69 to 0.88 (rG) and 0.28 to 0.88 (rP). Generally, litter traits gave higher estimates than individual kit traits implying that selection criteria based on litter performance rather than on individual kit performance should be applied in genetic improvement of pre-weaning traits in rabbits raised in derived savanna zone.

Genetic parameters of growth traits and carcass weight of New Zealand white rabbits in a tropical dry forest area

“…The mean LB value obtained here was higher than that presented by Gambo et al [ 4 ] and Adeolu et al [ 8 ], but lower than the reports by Badawy et al [ 14 ] and Pycha et al [ 15 ]. The differences found between the different reports for BL may be due to the disparity in the conception rate and the maternal effect, which is generally determined by the number of eggs matured, fertilized, and implanted by the doe [ 8 ].…”

“…The mean LB value obtained here was higher than that presented by Gambo et al [ 4 ] and Adeolu et al [ 8 ], but lower than the reports by Badawy et al [ 14 ] and Pycha et al [ 15 ]. The differences found between the different reports for BL may be due to the disparity in the conception rate and the maternal effect, which is generally determined by the number of eggs matured, fertilized, and implanted by the doe [ 8 ]. In this sense, it has been determined that the size of the litter has a significant effect on the future performance of the litter [ 16 ], so the lower the number of kits per mother, the higher the birth weight, body weight gain, and growth rate [ 4 ].…”

“…The estimate of h 2 obtained for LB in the present work is similar to those reported in the literature [ 30 ]. However, Adeolu et al [ 8 ] found higher values, and El-Atrouny et al [ 9 ] and Kosba et al [ 31 ] reported lower values. h 2 of BA was considered to be of low magnitude.…”

“…Thus, it is necessary to carry out genetic evaluation work of the reproducers, which requires characterized populations and large genetic variability. On this aspect, the success of the selection and improvement programs depends greatly [ 8 ].…”