Heat stress (HS) is the most important threat to modern-day livestock production, attributed to changes in climatic conditions. Hyperthermia commonly observed during HS has an adverse effect on the animals feed intake, digestibility, and production [1], [2]. Further, heat stress induced dehydration and nutritional stress result in haemoconcentration leading to alteration in blood biochemical indices [3]. Also, stress affects the normal functioning of vital organs namely, liver and kidney [4]. Heat stress diverts blood to the skin for heat dissipation leading to hypoxia and nutrient restriction in the intestine [5] resulting in oxidative stress by increasing reactive oxygen species, in addition to compromised immune responses [6]. Hence, animals exposed to HS are susceptible to endotoxemia or secondary bacterial infections. To maintain optimal health conditions, the demand for nutrients up-regulating antioxidants, and immune responses increases under the HS situation [1], [5]. Zinc (Zn) is one such important nutrient (trace element) that has a multifunctional role in regulating feed intake, health, and production. Moreover, Zn is involved in the metabolism of carbohydrates, lipids, proteins, and nucleic acids [7]. The Zn-containing antioxidant metalloenzyme superoxide dismutase (SOD) and metallothionein proteins scavenge free radicals generated in the body to counter oxidative stress [1], [8]. Zn mediates its immune function by protecting the epidermal and epithelial cell lining and regulating B-lymphocytes for antibody production [7], [9]. Various studies exploring the impacts of higher levels of Zn supplementation in livestock under normal environmental conditions demonstrated augmentation of feed intake, nutrient digestibility, and growth rate [10], [11]. Similarly, enhanced SOD, catalase, and total antioxidant capacity [8], as well as increased antibody production against the antigen in different experimental trials [12], indicates the greater requirement of Zn for additional benefits. However, in vitro studies [13] and in vivo studies in pigs [14] and quail [15] substantiated higher Zn supplementation to prevent adverse effects of HS. Rats exhibited enhanced growth, antioxidant, and immune function by supplementing Zn enriched probiotics [16] in HS conditions. However, an assessment of the functional requirements of dietary Zn alone in ameliorating the HS condition in rats is necessary. Hence, the current study has been carried out under two different environmental conditions to evaluate the Zn requirement to enhance serum minerals, antioxidant capacity, hormones, and immune function, along with blood biochemical attributes.