Nutritional, metabolic, and intestinal responses to dried Opuntia ficus-indica cladode powder in growing rabbits

Opuntia ficus-indica cladodes contain fiber and bioactive compounds, but their functional value at moderate inclusion levels in rabbit diets remains unclear. This study evaluated the effects of dried O. ficus-indica cladode powder on nutrient utilization, redox status, lipid metabolism, caecal characteristics, and duodenal morphology in growing rabbits. Seventy male Italian White rabbits were randomly assigned at 42 days of age to a control diet (CON) or a diet containing 50 g/kg, as-fed, of dried cladode powder (OP5; n = 35 per treatment) and fed until 84 days of age. Dietary OP5 did not affect growth performance, feed conversion ratio, slaughter traits, or meat proximate composition (p > 0.05). However, crude fiber and neutral detergent fiber digestibility increased by approximately 23 and 18%, respectively (p < 0.001). Serum total antioxidant capacity increased by 54% (p = 0.001), whereas malondialdehyde, total cholesterol, and triglycerides decreased (p ≤ 0.006). Superoxide dismutase and hepatic enzyme activities were unaffected. Caecal pH, ammonia-N, total volatile fatty acids, and total cultivable bacterial counts did not change. Nevertheless, OP5 reduced Escherichia coli (p < 0.001) and increased Lactobacillus spp. (p = 0.029). Villus height and crypt depth increased (p < 0.001), while the villus height-to-crypt depth ratio decreased (p = 0.001), indicating duodenal remodelling. Overall, 5% dried cladode powder was well tolerated and showed potential as a functional ingredient for growing rabbits, with responses involving fiber utilization and selected antioxidant, lipid, and caecal microbial indicators without compromising productive performance.