Effect of heat stress on milk production of goats from Alpine and Saanen breeds in Brazil.

The purpose of this bibliography review was to approach the thermal comfort rates on milk production of goats from Alpine and Saanen breeds in Brazil. The caloric stress caused by weather changes to which the animals are submitted, influence on the mechanisms of normal physiological processes of the body. Thus, the effect on the lactation process in goats can be mentioned, where it decreases the amount of water in the body with the consequent decrease in synthesis and milk ejection interfering in the production of hormone prolactin and growth hormone. The animal?s interaction with the environment must be considered when the aim in livestock farming is welfare, because the different responses of the animal to the peculiarities of each region are crucial for the success of the animal adaptation. So, the correct identification of the factors that influence the productive life of the animal, such as the stress caused by the seasonal fluctuations of the environment, allow production systems management, making it possible to make them sustainable and viable. The maintenance of these parameters in normal levels is very important, to the point of being used in the evaluation of climate adaptability of breeds to a certain environmental condition. In this way, the concerns about animal welfare and environmental comfort are due to the climatic variables and the behavioral, physiological and productive responses are prevailing when implementing the suitability of certain production systems.

Energy balance model applied to pasture experimental areas in São Paulo State, Brazil.

The Simple Algorithm for Evapotranspiration Retrieving (SAFER) was used to estimate biophysical parameters and theenergy balance components in two different pasture experimental areas, in the São Paulo state, Brazil. The experimentalpastures consist in six rotational (RGS) and three continuous grazing systems (CGS) paddocks. Landsat-8 images from2013 and 2015 dry and rainy seasons were used, as these presented similar hydrological cycle, with 1,600 mm and 1,613mm of annual precipitation, resulting in 19 cloud-free images. Bands 1 to 7 and thermal bands 10 and 11 were used withweather data from a station located nearthe experimental area. NDVI, biomass, evapotranspiration and latent heat flux(λE) temporal values statistically differ CGS from RGS areas. Grazing systems influences the energy partition and theseresults indicate that RGS benefits biomass production, evapotranspiration and the microclimate, due higher LE values.SAFER is a feasible tool to estimate biophysical parameters and energy balance components in pasture and has potentialto discriminate continuous and rotation grazing systems in a temporal analysis.