Effects of cowpea protein hydrolysates on the growth performance, lipid profile, antioxidant status, tissue histomorphology, and expression of caspase-3 and tumor necrosis factor-α in broiler chickens

The impact of cowpea protein hydrolysate (CPH) dietary supplementation was assessed on the growth performance, blood hematology, liver histomorphology, antioxidant status, and inflammatory responses in broiler chickens. Five hundred 3-d-old broiler chickens (88.72 g ± 0.20) were assigned to 5 experimental treatments (10 replicates/treatment), the basal diet supplemented with 5 inclusion rates of CPH: 0, 2, 4, 6, or 8 g/kg. Throughout the experimental periods, broiler chickens fed diets supplemented with CPH showed no change in the growth rate. The 2 g CPH/kg treatment increased the red blood cell count, hemoglobin concentration, packed cell volume percentage, white blood cell count, and lymphocyte count (linear, P < 0.01; quadratic, P < 0.05). Uric acid concentration increased in the CPH-supplemented treatments (linear, P = 0.031). The inclusion of CPH reduced the total cholesterol (Linear, P = 0.03; quadratic, P = 0.02), the low-density lipoprotein concentrations (linear, P = 0.012), and the triglyceride concentrations (linear, P = 0.01). Dietary supplementation of CPH increased the total antioxidant capacity, catalase (linear, P < 0.001), and superoxide dismutase activity (linear, quadratic, P < 0.01). Supplementation of CPH showed a down-regulation of the expression of caspase-3 antibodies in the liver tissues (Linear, P < 0.01). Liver histoarchitecture was normal in all experimental treatments. It can be concluded that dietary cowpea protein hydrolysate can be used as a potential protein supplement in broiler chicken diets to improve antioxidant status and lower the blood lipids without affecting the broiler chickens’ growth rate.