Effect of genotype and rearing system on the native immunity and oxidative status of growing rabbits

To investigate the effects of genotype and rearing system on innate immunity and oxidative status, 40 weaned commercial hybrid (H) rabbits and 40 rabbits of a local population (LP) were assigned to two rearing systems: cage (17 rabbits/m2) and pen (1x2 m, 10 rabbits/m2). Rearing H rabbits in pen resulted in a higher lysozyme concentration (P<0.05), an increased bactericidal ac- tivity (P<0.05) and a lower complement haemolytic activity (P<0.05) with respect to those reared in cage. Opposite results were obtained for LP rabbits. In addition, genotype H was more susceptibility to inflammation than LP in pen, whereas genotype LP suffered more in cage. A higher lipid (P<0.05) and protein (P<0.05) oxidation was found in Longissimus dorsi and Biceps femoris of rabbits H in pen compared to those in cage. An opposite trend was observed for LP rabbits. In cage, LP rabbits were more susceptible to oxidative stress than H rabbits. Taken together, our results show that immune and oxidative resistance ascribed to a specific genotype are important factors to be considered when a specific rearing system should be adopted. Considering this, rabbit LP seem to better adapt to larger spaces during growing.