Antioxidant and anticoccidial effects of garlic powder and sulfur amino acids on Eimeria-infected and uninfected broiler chickens

To study the anticoccidial and antioxidant effects of garlic powder (GP) and total sulfur amino acid (TSAA) on growth performance, faecal oocyst output, oxidative stress indicators and antioxidant status markers in broiler chickens, a 2 × 2 × 2 splitplot-factorial arrangement of treatments was used. A total of 480-day-old male broiler chickens were equally assigned to two plots. Two hundred forty chickens were challenged with Eimeria oocysts species mix by oral inoculation at day 34 (infected plot) and the other half was left unchallenged. In each plot, chickens were randomly assigned to four treatments with 5 replicates of 12 birds each, and fed one of the following diets: basal diet, basal diet plus 0.5% GP, basal diet plus 50% more TSAA, basal diet plus 0.5% GP and 50% more TSAA. The results showed that inoculation with 7.5 × 102 oocysts of Eimeria mixed species significantly reduced growth performance (P<0.05) and increased nitric oxide (NO) and malonyldialdehyde (MDA), but did not change the hepatic activity of superoxide dismutase (SOD) and the glutathione peroxidase (GPX) activity. Growth depression and increased NO and MDA were greater in infected than uninfected birds. In the infected birds fed with the basal diet without any supplementation, NO and MDA were significantly greater (P<0.05) in comparison with other groups. Faecal oocyst output significantly decreased with the supplementation of GP and TSAA in infected birds (P<0.05). In conclusion, the supplementation of GP and 50% TSAA individually or in combination with the basal diet significantly improved ADG (P<0.05) and decreased OPG, MDA and NO. Moreover, no changes in the antioxidant enzymes were observed in birds infected with Eimeria.