This study aimed to evaluate the physiological parameters and performance of sheep Santa Inês and Dorperlambs ½-SantaInes in summer and winter seasons. 160 Santa Inês sheep and 189 ½ Dorper lambs were used - Santa Inês completely randomized in two treatments, summer: 80 sheep and 92 lambs and winter: 80 sheep and 97 lambs.Was recorded environmental the environmental parameters of air temperature (Ta°C), relative humidity (% RH), wind speed (Vvms- 1) and black globe temperature (Tg°C) and physiological parameters of rectal temperature (Tr°C), respiratory rate (RR mov.min-1) and heart rate (HR beat.min - 1). The body condition of the ewes was measured at birth. In the final third of gestation there was a significant effect P < 0.05) for TR, FR and HR on sheep, where in summer the values were 40.63°C, 102.58 (mov.min-1) and 128,34 (beat.min-1) with 46 ICT, and winter was 38.34°C , 35.71 (mov.min-1), 77.96 (beat.min-1) with ICT of 14. The values of TR, RR and HR at birth and weaning were also significant between the summer and winter seasons. Differences were observed (P < 0.05) for TR, RR and HR of lambs at birth and weaning between summer and winter. The weight at birth (4.51 ± 2.86) and weaning (16.91 ± 3.91) were higher for those born in the summer. During the summer Santa Inês ewes were superior in body condition score, favoring births of heavier lambs and consequently higher weaning weight with higher rate of survival than those found in winter.
bioclimatology; body temperature; heartbeats; respiratory Rate