Performance response, carcass evaluation and economic benefit of rabbits fed sorghum offal-based diets

Abstract

An eight-week feeding trial was conducted to investigate the performance, carcass quality, haematological indices and economics of production of rabbits fed dietary sorghum offal substitute for maize grain. A total of forty (40) weaned rabbits with a mean weight range of 820-850 g were randomly distributed to five treatment diets where 0, 25, 50, 75 and 100% of sorghum offal replaced maize grain in the gross feed composition to give Diets 1 (control), 2, 3, 4 and 5, respectively. Each treatment diet was replicated eight times with a rabbit taken as a replicate. The determined chemical composition of the experimental diets ranged between 17.12% and17.43% for crude protein (CP), 11.48 and 14.89% for crude fibre (CF), 5.04 and 7.74% for ether extract or fat (EE), 54.17 and 56.41% for  nitrogen free extract (NFE) and 3069.35kcal/kg to 3241.17ME(kcal/kg). While the results on performance showed no significant difference (P>0.05) in feed intake by rabbits fed the five test diets, there appeared to be significant decrease (P<0.05) in the weight gain and feed conversion ratio of rabbits fed 50 to 100% sorghum offal-based diets. Carcass cuts that showed significant reduction (P<0.05) at 75 and 100% sorghum offal-based diets are the carcass weight, thigh, loin, shoulder and ribs weights. Organs such as liver, kidney, heart and pancreas weights  measured were significantly higher (P<0.05) at 75 and 100% sorghum offal-based diets. Haematological profile such as Packed Cell Volume
(PCV), Red Blood Cells (RBC), White Blood Cells (WBC), Mean Cell Volume
(MCV) and White Blood Counts such as neutrophil and basophil showed significant difference (P<0.05) at 75% and 100% sorghum offal-based diets. The serum metabolites such as albumin, globulin, cholesterol and urea showed a similar trend of significant difference (P<0.05) at 75% and 100% sorghum offal inclusion compared to other test diets. For economic production, the study revealed an optimum inclusion of sorghum offal at 50% (24.60 g/kg in feed composition) for maize grain in rabbit concentrate feed is possible. Above this level, a loss of N23.17 and N13.16 was recorded as evidenced by the cost differential and benefit cost analysis.

Key words: Performance, Haematology, Serum, Sorghum offal, Rabbit