Effect of Dietary Protein Levels on Performance and Health Status of Adult Companion Rabbits

Three isoenergy diets with different crude protein (CP) levels (H = 175, M = 173, and L = 165 g/kg, as is), were fed to 117 sex balanced rabbits (coloured dwarf breed) from 28 to 45 weeks of age. Feed intake, body weight, and fatness were unaffected by the dietary treatment. By reducing dietary CP content, rabbits in group L had a significantly reduced proportion of digestible protein (DP) relative to maintenance requirements compared to group H; <i>p</i> < 0.001), but still exceeding their DP needs. The initial body weight of females was significantly greater than that of males, a difference maintained throughout the study period. Males consumed more feed than females (86.0 vs. 75.2 g/d, <i>p</i> < 0.001) and at 45th week, the skin fold width of males was higher than that of females (<i>p</i> < 0.001). DP balance remained positive in both sexes but was higher in males than females (+3.37 vs. +2.50 g DP/d; <i>p</i> < 0.001). Contrarily, the energy balance was positive in males (+57.9 kJ DE/d) and negative in females (-20.3 kJ DE/d). In conclusion, a dietary CP level of 165 g/kg is considered adequate for adult companion rabbits at maintenance. It is therefore advisable to diversify diets by sex to better meet their nutritional requirements.