3-hydroxy-3-methylbutyrate and 2-oxoisocaproate affect body composition and cholesterol concentration in rabbits

This study was conducted to assess the effect of increasing amounts of 3-hy droxy-3-methylbutyrate (HMB) and 2-oxoisocaproate (KIC) given as a dietary supplement on performance and body composition in growing rabbits. In addit ion, plasma, liver, muscle and duodenum cholesterol were also determined. M ale White Termonde rabbits were fed either experimental diets containing in creasing amounts of HMB (range 0.005-0.1% of the dietary dry matter) and KI C (range 0.02-0.1% of the diet dry matter) or control diets containing CaCO 3 for 9 weeks. Experimental treatment did not affect growth rare. protein c ontent of the total carcass did not differ among groups, whereas carcass fa t content decreased by up to 30%, in proportion to the amount of HMB and KI C administered (p < 0.05). The same protein content calculated as a percent age of dry matter increased by 12% and protein:fat ratio by 42% in the rabb its receiving 0.1% of dietary HMB (p < 0.05). Total blood cholesterol decre ased during the first 3 weeks of treatment and was sustained at that low le vel (p < 0.05). Duodenum cholesterol decreased up to 15% (for 0.1% KIC p < 0.01). In conclusion, dietary HMB/KIC supplementation can beneficially affe ct some carcass characteristics in rabbits, especially concerning elevated body protein:fat ratio and decreased plasma and intestinal cholesterol.