UTTAR PRADESH JOURNAL OF ZOOLOGY

Changing environmental conditions driven by climate variability, rising temperatures, and increased frequency of extreme events are exerting profound effects on animal physiology. This review synthesizes recent advances in understanding physiological responses and adaptive mechanisms across livestock, poultry, wildlife, and aquatic species. Environmental stressors such as temperature, humidity, radiation, nutritional limitations, and pollutants disrupt homeostasis, leading to alterations in endocrine regulation, metabolic pathways, immune function, and behaviour. Activation of neuroendocrine pathways, particularly the hypothalamic–pituitary–adrenal axis, plays a central role in mediating stress responses through hormonal modulation and energy redistribution. Thermoregulatory processes, including sweating, panting, and behavioural adjustments, are critical for maintaining heat balance, while cellular responses such as heat shock protein expression and antioxidant defence systems protect against oxidative damage. Climate change impacts productivity by reducing milk yield, growth rate, reproductive efficiency, and feed utilization, while also increasing disease susceptibility and mortality risks. Species-specific differences in physiological adaptation highlight the importance of genetic and ecological factors in determining resilience. Advances in molecular biology, including genomics, transcriptomics, epigenetics, and gene editing, have enhanced the identification of stress-resilient traits and improved breeding strategies. Precision livestock technologies, sensor-based monitoring, and artificial intelligence are transforming animal management by enabling real-time assessment and targeted interventions. Mitigation approaches such as improved housing, cooling systems, nutritional strategies, and selective breeding contribute to enhancing adaptive capacity and sustaining productivity. An integrated approach combining physiological, genetic, nutritional, and technological strategies is essential to address the challenges posed by environmental change. Strengthening adaptive mechanisms, improving management practices, and promoting sustainable systems are critical for ensuring animal health, welfare, and long-term productivity in dynamic environmental conditions.