Growth response and nutrient digestibility of pre-pubertal rabbit bucks fed cottonseed cake-based diets supplemented with vitamin E

Abstract

A study was conducted to investigate the growth response and nutrient digestibility in rabbit bucks fed cottonseed cake (CSC)-based diets supplemented with vitamin E. 64 weanling rabbit bucks, aged five to six weeks and weighing averagely 511.28 g were involved in the study. The bucks were randomly allocated to eight treatment combinations comprising four levels (0, 5, 10 and 15%) of CSC and two levels (0 and 30 mg/kg diet) of vitamin E in a 2 × 4 factorial experiment. Eight (8) bucks were assigned to each dietary treatment and fed the experimental diets for eight weeks. The CSC level had no significant (p > 0.05) effect on feed intake, final body weight, weekly weight gain and feed efficiency. Also, vitamin E supplementation did not affect (p > 0.05) the growth parameters. All the growth parameters measured were not affected (p > 0.05) by the interaction between CSC and vitamin E supplementation. Digestibility of nutrients-dry matter, crude protein, crude fibre, ether extract and ash was not significantly (p > 0.05) affected by CSC level, vitamin E supplementation and their interaction. Mortality was high for the bucks that were fed CSC irrespective of vitamin E supplementation. It was concluded that, although rabbit bucks may be fed CSC up to 15% inclusion level in diet for meat production, it is deleterious for young bucks whose digestive tract is not mature enough to handle gossypol in the CSC.

Key words: Growth, digestibility, pre-pubertal bucks, cottonseed cake, vitamin E.