author(s)
Sunil Arora and Nalini Kataria

abstract
The effect of heat load index (HLI) on metabolic controllers of Sirohi goat from semi-arid tracts of Rajasthan was evaluated. Apparently healthy male and female Sirohi goat of different age groups from unorganized sector (Udaipur district, Rajasthan) were assessed. Obtaining of blood samples was carried out during environmental periods (EPs) of the year encompassing intervening EP (October-November); dry-hot EP (April, May and June); humid-hot EP (July, August and September) and cold EP (December and January). The range of average HLI values acquired during intervening or congenial period was 26.00-94.00. Dry-hot and humid-hot periods divulged greater values of HLI. The stress was assessed on the basis of metabolic controllers viz. serum Ornithine Carbamoyl Transferase (OCT) and serum Hexokiase (HK) enzymes. The mean values of both the serum enzymes were observed to be significantly (p≤0.05) greater during dry-hot, humid-hot and cold EPS as compared to intervening or control mean value. OCT enzyme exhibited maximum activities during humid-hot EP and the maximum percent change in the mean value of serum OCT was found to be + 154.52, whereas HK enzyme exhibited maximum activities during cold EP, maximum percent change in the mean value of HK was instituted to be + 25.93 during cold, as compared to equivalent intervening EP values. Outcome has shown bang of extreme environmental periods and their effects on metabolism through the metabolic controllers. This enlightened the change in functions of liver owing to HLI. It is important that pattern of change in liver functions and cellular metabolism coincided that of HLI. It can be concluded that abiotic stressors can impinge stimulation of metabolic controllers and liver activity. It is worth mentioning that Sirohi goat of all physiological states were affected with extreme environmental periods.