EVALUATION OF NUTRITIONAL VALUE OF FIELD LEGUMES USING RABBIT (ORYCTALOGUS CUNNICULUS) AS THE ANIMAL FOR BIOASSAY

Abstract

Tropical field legumes are currently used in the feeding of livestock, mainly as a source of protein. However their nutritional values have not been adequately evaluated by animal nutritionists. This experiment was carried out to determine the nutritional value of four field legumes using growing rabbits as the animal for bioassay. Thirty Newzealand White, one (1) month old rabbits were randomly placed in rabbit cages in pairs. The design was a CRD There were 5 treatments representing the legumes i.e. Lucerne, Desmodium, Vetch and Beans and a control of Rhodes grass hay and each treatment was replicated thrice. Feed and water was given adlibitum. From the five Feeds, samples were taken in duplicate for proximate analysis to evaluate their nutritive value in terms of DM, CP, CF, Mineral, NDF and ME (Kcal). Data on daily feed intake was used to assess the growth rate and feed conversion efficiency. Daily rectal temperatures were taken from the 2nd week of experiment. This was done randomly on three rabbits in each treatment for a period of 2 weeks, this was to monitor possible clinical signs of toxicity, especially hypothermia. At the end of the experiment, two rabbits from each treatment were sacrificed and their gastro-intestinal organs weighed and examined for any toxic effects of the legumes. Research design was a completely randomized design (CRD) and data was analysis using analysis of variance (ANOVA). The results demonstrated that beans had the highest CP of 28.98% while Vetch, Desmodium and Lucerne had % CP of 25.90, 21.05, and 20.66, respectively. However, rabbit fed on Desmodium had the best average daily gain (ADG) of 12.72gm, and feed conversion efficiency of 0.097. Toxicity was measured through comparison of rectal body temperature, ante-mortem and post mortem findings on the different feeds which revealed that rabbits fed on Desmodium had the least toxicity score while the beans had the highest. From these results it can be concluded that Desmodium is the best legume as a protein source and the least toxic for growing rabbits.