Effect of altered ambient temperature through shelter modifications on physiological indicators of Malpura lambs reared in semi-arid region during winter

Microclimatic factors are of crucial aspect for the welfare of animals. Therefore, a study was conducted to assess the effect of altered ambient temperature through shelter modifications on physiological indicators of Malpura lambs reared in the semi-arid region during winter. Twenty-one Malpura lambs of 3-5 week age and average body weight 9.97 ± 0.51 kg were used in the present study. The lambs were divided into three groups (eg. G1, G2, and G3) and were kept in the different microenvironment by manipulation of shelter design. The G1 lambs were maintained at lower minimum temperature (8.59 ± 0.71 °C) in asbestos roofed shed, while G2 lambs were maintained at higher minimum temperature (14.59 ± 0.54 °C) in local handmade bamboo dome structure, and G3 lambs were kept at a medium minimum temperature (11.84 ± 0.64 °C) in thermocol insulated roofed shed from evening 18:30 h to morning 07:00 h. The study was carried out for one month between January and February. The parameters studied were physiological response (respiration rate, pulse rate, rectal temperature), skin temperature, blood metabolites and endocrine profile. The data were analyzed by general linear models. Higher average daily weight gain was recorded in the lambs kept in higher minimum temperature groups (20.54% higher in G2 and 24.68% higher in G3) as compared to G1 lambs. Microenvironment manipulation had no significant (P > 0.05) effect on most of the physiological response and skin temperature except morning respiration rate within low-temperature range. The present study reveals that Hb, PCV, T3, and cortisol level were significantly (P < 0.05) influenced by microenvironment manipulation. The results of the study indicated that altered ambient temperature through altered shelter design of housing for raising of lambs in the semi-arid tropical region may support animal welfare during chilling nights of the winter.