Effect of exogenous lipase supplementation in low-energy diets on growth performance, nutrient digestibility, blood parameters, antioxidative status and economic indices of broilers

A total of 300 one-day-old chicks were divided into five treatments. Five diets were formulated as follows: PC (positive control), NC1 (negative control 1; ME was reduced by 80 kcal/kg diet), NC2 (negative control 2; ME was reduced by 100 kcal/kg diet), NC1 with lipase (negative control 1+ lipase at 200 g/ton diet) and NC2 (negative control 2+ lipase at 200 g/ton diet). Body weight was higher (P < 0.05) in birds fed the PC diet and the NC1 diet supplemented with lipase, and lower for those that received the NC2 diet. Moreover, the highest digestibility of CP and ether extract was observed in the groups fed NC1 supplemented with lipase and PC. The highest glutathione peroxidase level was observed in the group fed the NC1 diet, and the lowest malondialdehyde level was recorded in the groups fed low-energy diets supplemented with lipase, followed by those fed low-energy diets without lipase. Additionally, the group reared on the NC1 diet supplemented with lipase exhibited the highest economic indices and the lowest (P < 0.05) feed costs per kg body weight gain, without significant differences from the PC diet-fed group. It could be concluded that supplementation of lipase to reduced-energy diets markedly improved performance, nutrient utilization, economic efficiency and antioxidative status of broilers.