Effects of curcumin on the growth performance, apparent nutrient digestibility, intestinal morphology, digestive enzyme activity, and antioxidant capacity of meat rabbits

The purpose of this study was to investigate the effect of curcumin on the growth performance, slaughter performance, apparent nutrient digestibility, intestinal morphology, and digestive enzyme activity of meat rabbits. One hundred and sixty healthy weaned meat rabbits were randomly divided into four groups (forty replicates per group and one rabbit per replicate). The control group was fed a basal diet and the test groups (T1, T2 and T3) were fed diets supplemented with 50, 100 and 150 g/t curcumin in the basal diet, respectively. The study lasted for 28 days, including a pre-feeding period of 7 days and a formal trial period of 21 days. The results showed that diets supplemented with curcumin significantly increased rabbits' body weight gain and average daily feed intake; Apparent digestibility of energy, crude protein, crude fat, crude fibre, NDF and ADF; Jejunal villus height, the ratio of villus height to crypt depth; The activities of amylase and lipase in jejunal and caecal digesta and cellulase in caecal digesta; Caecal mucosal thickness, eviscerated dressing percentage, and dorsal and abdominal hair thickness (p < .05). Diets supplemented with curcumin significantly decreased rabbits' feed to gain ratio, jejunal crypt depth and thickness of the intestinal wall (p < .05). In conclusion, curcumin is a kind of valuable feed additive, which can improve the nutrient digestibility, growth performance, slaughter ratio and fur development of meat rabbits by improving digestive tract development and digestive enzyme activity. The appropriate dosage in the meat rabbit diet is 100 g/t.