Effect of cold stress on growth, physiological responses, blood metabolites and hormonal profile of native Malpura lambs under hot semi-arid tropics of India

Abstract

The study was conducted to determine the effect of cold stress on growth, physiological responses, blood metabolites and hormones. Growing native Malpura lambs (18), 45 to 60 days of age, 14.8 kg body-weight, were used in this study. The lambs were randomly divided into 2 groups as group 1 (9) and group 2 (9). The experiment was conducted from mid-January to mid-February when the environmental temperature was at the lowest. The lambs of G1 were kept under the asbestos shed open from the sides while the lambs of G2 were provided protection against the cold weather. The body weight (kg), physiological responses i.e. respiration rate (RR, breath/min), pulse rate (PR, beat/min) and rectal temperature (RT,°C) were recorded at fortnightly interval. The blood samples were also collected at fortnightly interval and analyzed for packed cell volume (PCV,%), haemoglobin (Hb, g/dl) and glucose (mg/dl). Besides the T3 (nmol/l), T4 (nmol/l) and cortisol (nmol/l) were also estimated. The lambs of G1 had higher RR, PR and RT than the G2 lambs. A significant increase in the PCV, Hb and glucose was observed in G1 lambs as compared to G2. The ADG was significantly higher in G2 lambs as compared to G1 lambs.