European Poultry Science, cilt.83, 2019 (SCI-Expanded)
This experiment was conducted to evaluate the effects of dietary bromelain supplementation on laying performance, egg nutrient profile, serum traits and antioxidant status. A total of 96 Lohmann White laying hens (28-weeks-old) were fed diets containing different concentrations of bromelain (0, 0.15, 0.30 and 0.45 g/kg) during an 8-weeks experimental period. Each treatment was replicated in six cages. Data were analysed using the GLM Procedure, including orthogonal (control vs. bromelain) and polynomial (dose-response) contrasts statements. Bromelain supplementation did not affect the laying performance and egg quality parameters. Bromelain supplementation increased egg yolk (P < 0.0001) serum protein (P < 0.04) concentrations, decreased egg yolk triacylglycerol fraction (P < 0.0001) and serum cholesterol concentration (P < 0.0003), but did not affect egg yolk cholesterol fraction. Hens fed diets supplemented with the bromelain had higher concentrations of antioxidant enzymes (265 vs. 210 U/g protein for superoxide dismutase; 16.31 vs. 7.95 U/g Hb for glutathione peroxidase and 4.70 vs. 2.33 U/g Hb for glutathione-S-transferase; P < 0.0001) and lower malondialdehyde (114 vs. 86 nmol/ml, P < 0.05) in serum than hens fed the control diet. In conclusion, bromelain could be supplemented up to 0.45 g/kg in the laying hen diet to enhance antioxidant capacity.