Effect of Climatic Stress on Behavior, Milk Production and Milk Composition of Dairy Cattle: A Bird’s Eye View

Aim of the Study: The aim of this study was to explore how climatic heat stress during Pakistan’s extended summer season affects dairy cattle productivity, physiological responses, behaviour, and milk quality, with particular focus on somatic cell count and thermal stress indicators. Methodology: This study was based on a critical review of available scientific literature and reported field observations related to heat stress in dairy cattle. Published research concerning temperature–humidity index (THI), animal responses to thermal stress, changes in milk yield and composition, and the use of cooling systems such as fans and sprinklers was examined, with emphasis on conditions comparable to Pakistan’s climate. Findings: The reviewed evidence showed that heat stress negatively influences milk production, feeding behaviour, and metabolic balance in dairy cattle. Elevated environmental temperatures cause a shift in nutrient utilization from production towards maintenance, resulting in reduced fertility and higher disease risk. An increase in somatic cell count was frequently observed, indicating stress on the mammary gland and reduced milk quality. Cooling interventions generally improved animal comfort and reduced stress, although their effectiveness depended on management practices and environmental severity. Conclusion: Heat stress remains a major limiting factor for dairy productivity under Pakistan’s climatic conditions. While body cooling strategies show potential in reducing its adverse effects, locally generated comparative data are still limited. Further field-based studies are needed to develop climate-specific management practices that can sustainably improve dairy cattle performance.