Genetic and non-genetic factors affecting milk yield of rabbit does under hot semi-arid climate.

Abstract

Forty five lactation records from 37 does of three breeds (White Giant: 16; Grey Giant: 12 and Soviet Chinchilla: 9) were analysed to study the effects of breed, parity, week of lactation and doe weight at kindling on milk production. ANOVA results showed that breed of the doe was important (P<0.07) for average weekly (600g) milk yield of the doe only and not for lactation (3600 g) yield, although White Giant does had numerically higher (625g per week and 3758g per lactation) production than did the does of other breeds. Effects of week of lactation, parity order and covariate of doe weight at kindling were significant in accounting for variation in milk yield. Peak of milk yield was reached in third (765g) week/18th day of lactation. Least squares means of doe body weight, litter size at birth and weaning and litter weight at birth and weaning were 3.1 O ± 0.1 kg, 6.5 ± 0.3 and 5. 7 ± 0.3, 383.9 ± 16.5 and 3. 7 ± 0.2kg, respectively. Of the 293 kits from 45 litters at birth, 255 kits were weaned resulting in overall pre-weaning mortality of 12.4 %. The average age at kindling was 11.0 months. Medium size but significant (P<0.05) residual correlation of milk yield with litter size (0.44) was observed. Other correlations of milk yield with litter size and weight at birth were low (0.21-0.29) and non significant. Lactation curves were unique to each breed and milk yield was influenced by several factors. Litter weight at birth and at weaning was influenced by all the above factors, except the non significant effect of doe weight on litter weight at birth.