The objective of this study was to evaluate and compare physical parameters in groups of sheep with different phenotypic characteristics in the Centre-west region of Brazil. Five groups of sheep, with nine animals per group, were selected, three groups of Santa Inês animals with different coat colours (white, brown and black), one group with crossbred animals (Santa Inês × Bergamasca) and one group with animals of the Bergamasca breed. The following traits were evaluated: coat thickness, number and length of hair, pigmentation level in the coat and the skin as well as the percentage area of sweats glands in the skin tissue, carried out by histological analysis. The number of hairs and the area of sweats glands were not significantly different between the evaluated groups. The Bergamasca breed showed low pigmentation of the skin and long hairs. The levels of pigmentation of the hair and of the skin were highly correlated. Between the Santa Inês groups, the group with white hair showed the better parameters for heat adaptation, while the brown hair group showed the lower heat adaptation when compared with another hair breed groups.

No abstract

This study compared the adaptation traits in common crosses of crossbred dairy cattle in central Brazil. Twenty animals of each of three genetic groups were used: zebu (Bos indicus), Simmental x Zebu (SZ) and Holstein x Zebu (HZ). The test measured variations in rectal temperature (RT), respiration rate (RR) and heart rate (HR) of animals in the shade and after exposure to the sun, as well as mean daily milk production throughout the lactation period. The procedure was repeated three times. There were significant interactions between test group and genetic group for the traits investigated and the correlations among traits were low. The RR of the crossbred groups may be controlling body temperature in such a way as not to cause an increase in RT. Milk production influenced RR in crossbred cows exposed to the sun, confirming their poorer adaptation in comparison with zebu cows. We observed that the adaptation can be measured in terms of production within the same genetic group. In conclusion, the crosses with European breeds produced more milk than zebu, although they were influenced by heat/solar radiation.

No abstract

This research aims to evaluate the microclimate of commercial loads of broiler chickens at different distances in the summer (rainy) and winter (dry) seasons and their effects on meat quality. Twelve broiler loads were monitored with a total of 24 crates per load. Data loggers were used to record temperature and relative humidity. The experiment followed a completely randomized design with 48 treatments in a factorial scheme (2 seasons: rainy and dry) x 2 (distances: short and long) x 12 (positions), with 3 replicates per experimental group. In the rainy season, meat quality was influenced by transport distance. For longer distances, it recorded the highest enthalpy comfort index (ECI), suggesting a tendency of dark, firm, and dry meat (DFD-like) and lower cooking losses (CL). The lowest ECI was recorded during the transport in dry season. Broiler chickens transported and slaughtered in the winter presented meat pH and L* (lightness) classified as "normal," but with higher cooking losses. For the shear force (SF), the seasons and distances had no significant influence on tenderness of the meat. Regarding the crate positioning in the load, no effect was observed during transport on this variable, given the meat quality characteristics of pH, L*, CL, and SF. These results suggest that the distance and the seasons present more influence on broiler meat quality than crate position in the truck.