Caractéristiques histochimiques du muscle et pH de la viande de lapin hybrides sacrifié à différents ages

The aim of this trial was to investigate the effects of high chromium (Cr) yeast supplemented diets on performance of growing-finishing rabbits. Ninety-six commercial hybrid rabbits, half males and half females, aged 35 days, were divided into 4 experimental groups and fed, ad libitum, for 49 days the same basal diet supplemented with 0 (T1), 400 (T2), 800 (T3) or 1600 (T4) ppb of Cr in the form of chromium enriched yeast. Control diet (T1) was analysed and found to contain 789 ppb Cr, a level which was probably due to the raw feed materials. The Cr content of all the diets was then proportionally increased. Chromium supplementation did not induce any significant differences in daily weight gain (32.2 to 32.9 g/d), feed to gain ratio, hot carcass weight, dress-out percentage, kidney weight, scapular fat deposit, or left hindleg percentage and meat/bone ratio. No differences in Cr level were observed for longissimus dorsi pH and colour. In contrast, the perirenal fat deposit was significantly higher in all rabbits which received the Cr supplementation (1.51 to 1.61 vs 1.02% of the carcass; P = 0.013) This was probably the result of a modification in lipid anabolism, in relation with the insulin activity, and particularly with the stimulation of the Glucose Tolerance Factor (GTF) which contains chromium. The liver weight of T3 rabbits was significantly higher than that of control group (4.94 vs 4.30% of the carcass; P = 0.028). The authors noted a substantial lack of any practical effects of Cr supplementation on growing rabbit performance under experimental conditions.[...]