Effects of dietary supplemental lysophospholipids and vitamin C on performance, antioxidant enzymes, lipid peroxidation, thyroid hormones and serum metabolites of broiler chickens reared under thermoneutral and high ambient temperature

: The effects of dietary supplemental lysophospholipids (LPLs) and vitamin C (VC) on performance, activity of antioxidant enzymes, and thyroid hormones of broiler chickens reared under thermoneutral and high ambient temperatures were evaluated. A total of 1,680 broiler chicks (Cobb 500) in finishing rearing period (days 21-38 of age) were allotted to two groups: thermoneutral (TN) and heat stress (HS). In the TN group, 480 chicks were subjected to four treatments with four replicates (n = 30) and maintained in usual ambient temperature (24 ± 1°C). In HS group, the remaining 1,200 chicks were subjected to four treatments with 10 replicates (n = 30) and exposed to high ambient temperature (34 ± 1°C for 8 hr daily). In both groups, four iso-caloric and iso-nitrogenous experimental diets based on a 2 × 2 factorial arrangements including supplemental LPLs (0 or 1,000 mg/kg) and VC (0 or 500 mg/kg) were formulated and used. Supplemental LPLs decreased (p < 0.05) body weight gain and increased FCR in the TN and HS groups. In the TN group, increased (p < 0.05) serum glucose was observed in chickens fed with dietary supplemental VC. In the HS group, decreased (p < 0.05) total protein concentration was detected in birds fed with supplemental LPLs. In both TN and HS groups, decreased (p < 0.05) uric acid concentration was detected in chicks fed with the VC-supplemented diets. A significant (p < 0.05) interaction between LPLs and VC on lactate concentration in the TN group was observed. In the HS group, decreased breast malondialdehyde concentration was detected in birds fed with the VC-supplemented diet. In the TN group, increased serum total antioxidant status was detected in birds fed with the LPLs-supplemented diet. In conclusion, LPLs improved oxidative stability and increased the antioxidant capacity of the serum. In addition, vitamin C modified heat stress and reduced lipid peroxidation.