Thermoregulatory capacity ofSanta Ineshair ewes of different genotypes associated with coat colors raised in a hot environment

The relationship between hair color characteristics and thermoregulatory responses in ewes raised in hot environment were evaluated. 15Santa Ineshair ewes of different genotypes associated with coat colors (light brown, dark brown and black) with body weight of 41.2 +/- 8.1 kg were evaluated during three consecutive days. Rectal temperature (R-T, degrees C) and coat surface temperature (C-ST, degrees C) of seven anatomical points (front, back, croup, loin, side, thigh, and belly) were measured during the morning and afternoon periods. Thermoregulatory responses were recorded along with meteorological variables. Heat tolerance index (H-TI) and thermal gradient (T-G, degrees C) were estimated for each genotype. R(T)and C(ST)were influenced by periods of the day (P< 0.05), being higher in the afternoon, but T(G)did not differ (P> 0.05) between periods. H-TI, C-ST, and T(G)were equal (P> 0.05) among the three genotypes. Only R(T)was higher in animals with dark brown coats compared to light brown, but equal to the black coat. It was observed that animals with black or dark brown hairs have a strong association between the C(ST)under study, and yet these had an inverse behavior with the R-T. Animals with a darker coat tend to trigger heat dissipation in various anatomical regions of the body, presenting dynamics in thermoregulatory responses in relation to those with lighter coats.Santa Inesewes have heat dissipation mechanisms as a function of different genotypes associated with coat colors, but have the same thermoregulatory aspects to maintain homeostasis, demonstrating an excellent adaptive mechanism in a hot environment.

Automated summary

The study found a relationship between hair color characteristics and thermoregulatory responses in ewes, with animals having darker coats showing stronger heat dissipation but similar thermoregulatory aspects in maintaining homeostasis compared to those with lighter coats. This suggests that sheep have adaptive mechanisms to regulate body temperature in hot environments regardless of coat color variations.