High-protein diets improve growth, carcass traits, and intestinal morphology of local rabbits under chronic heat stress.

This research assessed the impacts of high protein feeds on the performance of local rabbits under severe chronic heat stress (Temperature-Humidity Index (THI) = 31.47 ± 2). This research used 72 local rabbits aged 42 days of mixed sexes, which were distributed equally into three groups: low-protein (LP), medium-protein (MP) and high-protein (HP), receiving low, medium and high protein feeds containing 16.7%, 18.2% and 19.5% crude protein, respectively. Even though the rabbits were fed ad libitum, rabbits in HP and MP groups showed similar average daily gain and mean body weight, which were significantly higher than LP group by + 7.5% and + 6%, respectively. Feed conversion ratios were significantly lower in MP and HP rabbits than in the LP group, with reductions of 7% and 8%, respectively, reflecting better feed conversion efficiency in the former two groups. Compared to the LP group, both MP and HP groups showed similar improved slaughter weight (+ 7%), skin weight (+ 9%), and cold carcass weight (+ 8%), while showing different improved results for weight of kidneys (+ 6% and + 7%), weight of liver (+ 12% and + 15%), respectively. The LP group had a much higher Perirenal fat content (+ 42%, p < 0.0001) than the HP and MP groups, which showed similar results. Additionally, the height, width, and area of the villus in MP and HP rabbits were improved by 16-25%, indicating better nutrient absorption. The results of this study provide evidence that utilising dietary protein enrichment is beneficial in combating the adverse effects of weather-induced heat stress on the growth of local rabbits.