Vol. 9, Special Issue 1, Part M (2025)

The study evaluated histopathological alterations caused by heat stress in broilers and the potential mitigating effects of dried tamarind pulp powder (DTPP). A total of 150 broilers were divided into six groups (T₁–T₆) and reared for 35 days. T₁ group served as the healthy control, and T₂ as the heat-stressed (HS) control group. Groups T₃ and T₄ received DTPP (2.5 g/kg feed) and herbal Vitamin C (250 mg/kg feed) without heat stress, respectively. Groups T₅ and T₆, exposed to heat stress, were supplemented with DTPP and herbal Vitamin C, respectively.

Gross pathological changes in heat-stressed broilers included liver discoloration, congestion, vacuolar degeneration, and necrosis, impairing metabolism. Kidneys showed congestion, intertubular hemorrhages, and glomerular atrophy, reducing excretory efficiency. The heart exhibited petechial hemorrhages, myofibrillar degeneration, and pale coloration, compromising cardiovascular function. Enlarged spleens with lymphoid depletion, atrophied thymus and bursa of Fabricius weakened immunity. Intestinal congestion, villi desquamation, and epithelial exfoliation impaired nutrient absorption. Lungs displayed congestion and edema, while muscle degeneration affected growth and meat quality of broiler birds.

Histopathological evaluation revealed pronounced degenerative changes in heat-stressed birds (T₂), including cardiac myofibrillar degeneration, vascular congestion, liver centrilobular necrosis, widened sinusoidal spaces, and kidney tubular degeneration with necrotic foci. Spleen and thymus tissues exhibited lymphoid depletion and architectural distortion, while the bursa of Fabricius showed severe lymphoid population reduction and degeneration. However, broilers in T₅ (DTPP with HS) and T₆ (Vitamin C with HS) exhibited reduced severity of histopathological changes, with improved lymphoid populations in the spleen and bursa of Fabricius, and less intestinal degeneration of broiler birds.

Overall, DTPP supplementation significantly mitigated heat stress-induced pathological changes across multiple organ systems, highlighting its potential as an effective dietary intervention to enhance resilience in broilers under heat stress conditions.