Doe productivity indices and sire effects of a heterogeneous rabbit population in South-western Nigeria
Doe productivity indices are important in evaluating rabbit population since it influences the efficiency and profitability of rabbit production for small-holders and commercial rabbit production. Rabbits for this study were obtained from heterogeneous populations reared in south-western Nigeria, and a total of fifty-six adult rabbits (6 months old) comprising of 49 does and 7 sires were randomly allocated into sire families. Reproductive data were taken from each breeding doe and recorded for each sire family. The reproductive data obtained include annual productivity indices for each doe and sire family at birth, weaning and at week 12 post-partum. The total number of kits delivered at each kindling were recorded as the litter size at birth , the numbers weaned/doe/year were derived by multiplying the average litter size at weaning by number of litters/doe/year. The numbers of fryers/doe/year were obtained by multiplying average number weaned/doe by number of litters/doe/year multiplied by post weaning survival. Annual fryer yield (kg)/doe/year were obtained by multiplying total number of fryers/doe/year with live market weight (kg). Kilogram meat/doe/year were derived from the product of annual fryer yield (kg)/doe/year and the dressing percentage (0.55). Descriptive and inferential statistics were computed using SAS® 2004. Results showed that, the long kindling interval (93 to 115 days ) between two consecutive litters affected overall numerical doe productivity with a range of 6 to 27, 3 to 21 and 3 to 18 kits per doe/year at kindling, weaning and 12th week of age respectively. Annual fryer yield/doe/year was 20.24 Kg and the projected Kg meat/doe/year was 11.13 Kg. Mortality was highest in the first two weeks of life and continued to occur throughout the period of the study though at varying degrees across sire families. There was significant sire effect (P<0.05) in litter size at weaning and kindling- interval in the sire families. It was concluded that, the major factors affecting doe productivity indices in this population were low litter size at birth, long kindling interval and pre-weaning mortality. Thus, future genetic improvement programmes targeted towards productivity for this rabbit population must consider selection for traits which include increased litter size at birth, short kindling interval and low pre-weaning mortality in the maternal lines while litter size at weaning and kindling interval must be considered for the paternal lines.