Abstract
This study assessed the oxidative stress markers of 63 goat bucks of different breeds - Kalahari Red (KR), West African dwarf (WAD) and Kalawad (KW)] with 21 animals each. They were assigned to three age groups -– 7≤1,>1≤2 and, >2≤3 and >3≤4 years and evaluated across four seasons (early/late rainy and early/late dry) in a 23 × 3 × 4 factorial design. Animals were managed under uniform nutritional conditions for one year. On Bbimonthly basis, repeated blood samples on the same 63 animals (24 samples/animal over 12 months blood samples were collected to analyze serum antioxidant biomarkers and stress indicator. Three-way ANOVA was used for data analysis in SAS (1999). All determined serum antioxidant indices except malondialdehyde had significant (p <0.05) impact by breed. Glutathione and glutathione peroxidase were not statistically (p >0.05) modified by age. Every parameter considered was significantly (p <0.05) influenced by months of sampling (MOS) and season. All parameters considered were significantly (p <0.05) impacted by the interaction of breed/season, or age/season, age/MOS and breed/MOS. Age, breed, MOS and season exert significant but variable influences on serum antioxidant markers and malondialdehyde in KR, WAD and KW bucks under tropical conditions. These results indicated the importance of physiological monitoring for managing health, reproductive performance and provide reference values for selection and clinical assessments in heat-stressed environments.