Evaluation of Heat Stress Indicators and Biomarkers in Broiler Chickens Supplemented with Varying Amounts of Sodium Bicarbonate in the Semi-Arid Region of Sokoto, Nigeria

This study evaluated the efficacy of graded levels of dietary sodium bicarbonate (NaHCO₃) in reducing heat stress in broiler chickens reared in the semi-arid climate. A total of 180-day-old Ross 308 broiler chicks were randomly allotted to four dietary treatments: T1 (0 g NaHCO₃/100 kg feed), T2 (50 g/100 kg), T3 (100 g/100 kg), and T4 (150 g/100 kg), in a completely randomized design. The study lasted 49 days, during which environmental data, respiratory rate, rectal temperature, and blood serum samples for oxidative stress markers were collected. The results confirmed a significantly thermal challenge environment, with THI values frequently within the moderate to severe categories. Analysis of physiological responses showed that sodium bicarbonate supplementation had no significant (P>0.05) effect on respiratory rate or rectal temperature, indicating that the environmental thermal load was the dominant factor driving these primary stress indicators. However, the analysis of oxidative stress biomarkers revealed highly significant (P