Heat Stress Reduces Milk Production in India's Dairy Cattle

As temperatures increase, dairy cattle in India experience a range of physiological stresses that affect their productivity. When the ambient temperature exceeds a cow's thermal neutral zone, its ability to regulate body temperature is compromised. This results in reduced dry matter intake while water consumption and panting increase. These changes lead to a decrease in milk production, with European crossbred cows such as Holstein-Friesian and Jersey crosses experiencing more significant declines than indigenous Bos indicus breeds.

Long-term exposure to high temperatures not only affects milk yield but also impacts herd health and reproductive performance. Heat stress leads to hormonal imbalances and disrupted estrus cycles, resulting in silent heat, lowered conception rates, and prolonged calving intervals. Additionally, the immune function of cattle is suppressed, increasing the risk of mastitis, metabolic disorders, and vector-borne diseases. These health issues contribute to higher veterinary costs for farmers.

The economic impact of climate-induced heat stress is particularly severe for India's smallholder and landless dairy farmers. These farmers often operate with limited resources and may not afford cooling systems like industrial fans or climate-controlled housing. Consequently, they suffer from reduced milk revenues during heat events while facing increased costs for feed and livestock care.