Adaptabilidade e tolerância ao calor de ovinos criados no Semiárido do Estado da Paraíba.

Abstract

The objective of this study was to evaluate the morphophysiological characteristics of the adaptability of Soinga and Santa Inês sheep to the semi-arid climate, correlating their physiological responses with the degree of adaptability. The experiment was carried out in the municipality of Patos - PB, where 10 Santa Inês sheep and 10 Soinga sheep were used, all male, uncastrated, with a daily average of 180 days, confined in individual stalls. The experimental period was 15 days of adaptation to the management and 45 days of data collection. For the statistical analyzes, a completely randomized design (DIC) was used, with two treatments (Soinga and Santa Inês) and two shifts (morning and afternoon), with 10 replications, totaling 40 experimental plots. The data obtained were ITGU, TS, FR and TR. The averages found for the ITGU, 77.29 for the morning shift and 83.39 for the afternoon, indicating that the animals were submitted to thermal discomfort in both shifts. There was no significant difference between RR and TR between races within each shift. The analysis of variance revealed significant interaction (P <0.05) between race, shift and study sites for TS. Within the breed the Soinga sheep presented a lower mean TS, being this result attributed to the coloring characteristic of the pelage. In the afternoon shift, the animals had higher TS means, demonstrating that they had a higher incidence of solar radiation. The mean TS in each study site (head, neck and trunk) showed a significant effect (P <0.05), with a mean TS greater for the trunk, intermediate for the neck and lower for the head. In the trunk region, the Soinga animals showed an average TS lower than the Santa Inês breed. They concluded that despite being under thermal stress, both races demonstrated efficiency in the dissipation of absorbed heat. The Soinga animals present a better reflection of the solar radiation, maintaining a mean of TS lower.