Abstract

A sixteen-week study was conducted to investigate the effects of mimosine and tannin toxicity on rabbits (Orytolagus cunniculus) fed processed Leucaena leucocephala leaves (LLL). Thirty-six growing rabbits (mixed breed) of average weight of 625 g were used for the experiment. The rabbits were randomly allotted to nine experimental groups of four rabbits each in a 3 x 3 factorial arrangement. LLL were either sun dried (SDLLL), hot water processed (HWLLL) or ensiled (ELLL) for six weeks and included in three diets at 0, 10 and 20% levels respectively. Data were collected on feed intake, weight gain, feed conversion ratio and other performance characteristics of the fed rabbits. The data collected were subjected to analysis of variance (ANOVA) while the significant means were separated using Duncan’s multiple range test. The anti-nutritional analysis showed that SDLLL contained highest tannin (1.20%) and mimosine (1.64%) contents but HWLLL had the least tannin (0.77%) and mimosine (1.25%) respectively. The best feed conversion ratio (FCR) of 4.41^b and the highest (P < 0.05) weight gain were recorded by rabbits fed diets containing ELLL. The interaction effects showed that rabbits fed diets containing 20% SDLLL had alopaecia, necrotic spots, liver congestion, edema and highest percentage mortality. It was concluded that diets containing more than 1% of mimosine and tannin impaired the growth performance and had deleterious effects on liver of the rabbits.

Key words: Leucaena leucocephala, processing methods, rabbits and toxicity, anti-nutritional factors.