Seasonal variations in physio-biochemical profiles of Indian goats in the paradigm of hot and cold climate

Abstract

To explore the heat and cold adaptation in Indian goats by the physiological, haematological, blood biochemical parameters and their seasonal variations, this study was conducted on heat- and cold-adapted Indian goats maintained in their natural habitat. Study was carried out in three different phases coincide with the three seasons (winter, spring and summer). The levels of physiological responses, that is rectal temperature, respiration rate and pulse rate, were observed to be significantly (p < 0.01) lower in heat-adapted breeds and higher in cold-adapted breeds, whereas the levels of Hb, PCV and TEC were significantly (p < 0.01) higher in cold-adapted goats. Significantly (p < 0.01) higher levels of plasma thyroid hormones (thyroxine and triiodothyronine) and plasma stress enzyme (AST and ALT) were also observed in cold-adapted goats. Significant (p < 0.01) seasonal variations in physiological responses, haematological and blood biochemical parameters in both heat- and cold-adapted breeds were reported in this study. Physiological responses, plasma enzymes and plasma cortisol levels significantly (p < 0.01) increased during summer in all the goat breeds. The levels of haematological parameters (Hb, PCV, TEC and TLC) and plasma thyroid hormones (thyroxine and triiodothyronine) decreased during summer. The changes in physiological parameters during summer due to heat stress were higher in cold-adapted goats whereas the levels of changes in these parameters during winter due to cold were higher in heat-adapted goats. High neutrophil/lymphocyte ratio during summer in cold-adapted breeds is an indicator of higher level of stress. Decrease in plasma electrolytes (Na and K) during summer also observed in cold-adapted breeds during summer. The variations in physiological, haematological, blood biochemical parameters in heat- and cold-adapted goats may be due to their adaptation to different environmental and geographical conditions essential for their survival.