Evaluation of the nutritional value of field legumes using the rabbit (oryctalogus cunniculus) as the animal for bioassay

Rabbit farming (cunniculture) is not yet a popular livestock business enterprise in Kenya due to high feeding and lack of ready market for rabbit products. Cunniculture can be a profitable enterprise, but there is lack of knowledge on rabbits nutrition that is based on locally available forage germplasms. This has led to slow growth and low weight gain of rabbits. This experiment was carried out to determine the nutritional value of locally available 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. 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 treatments, samples were taken in duplicate for proximate analysis to evaluate their nutrient composition. Data on daily feed intake was used to assess the growth rate and feed conversion efficiency. Daily rectal temperature 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. 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 Desmodium had the best average daily gain (ADG) of 12.72gm, and feed conversion efficiency of 0.097. Toxicity investigation revealed that Desmodium had the least toxicity score while the beans had the highest. The research design was a CRD and data analysis was done using ANOVA and SPSS, while mean separation was done using Fischers Least Significant difference (LSD), (P<0.05). From these results it can be concluded that Desmodium is the best legume as a protein source for growing rabbits.