Incorporation of grass silage, whole cereal grains, cassava and cottonseed meal into diets of rabbits kept in a simulated tropical environment.

The growth and feed conversion of rabbits fed either grass silage or whole grains and supplementary pelleted concentrate of cassava/cottonseed diets were investigated. Poor quality grass silage (pH 4.9) was almost completely rejected by young rabbits initially fed either 17.8 g or 35.5 g DM/day of a supplementary concentrate. Rabbits on the lower level of concentrate provision lost 0.35 g liveweight per day. Rabbits initially weighing 1.77 kg fed complete pelleted diets containing 667 g/kg maize or 667 g/kg sorghum showed improved daily liveweight gains (22.6 g) over rabbits fed whole grains and pelleted supplements (19.4 g) in an experiment lasting 40 days. In a second experiment there were no significant effects of pelleting or type of cereal on liveweight gain or feed conversion ratio. Pelleting significantly improved crude protein digestibility of diets whilst maize diets were superior in DM, organic matter and crude protein digestibilities. The inclusion of cottonseed meal containing 700 mg/kg free gossypol in diets at levels of 150 and 300 g/kg did not affect growth rate or feed conversion in rabbits weighing 0.92 kg initially. These diets contained up to 364 g/kg cassava suggesting that this ingredient can be used in rabbit diets as an energy source in replacement for whole grains.