• Thermoregulatory Thermal Comfort Zones in Cattle:
• Upper Critical Temperature (UCT) is the ambient environmental temperature above which an animal must actively expend metabolic energy (sweating, panting) to dissipate heat and prevent lethal hyperthermia.
• Bos indicus (Zebu cattle - Hariana breed):
• Possess numerous large, functional sweat glands, sleek reflective coats, loose vascular skin with extensive dewlap/umbilical fold surface area, and lower basal metabolic rates.
• They have the highest UCT ($\approx 35 - 38^\circ\text{C}$) among cattle breeds.
• Bos taurus (Holstein Friesian, Jersey):
• Adapted to temperate climates; exhibit heavy heat stress with a lower UCT of $\approx 24 - 27^\circ\text{C}$.
• nalysis:
• (Hariana): Correct breed with the highest UCT.

Correct option: (2) Hariana