Bioclimatic evaluation of enthalpy of growing pigs housed and finishing in semiarid regions of Brazil

The environment where animals are bred must be favourable in order to achieve good production rates. Evaluation of the climatic environment within the house by means of the thermal comfort index becomes an important tool in ensuring that management practices are correct. Growing and finishing pigs are more susceptible to the effects of heat stress in most Brazilian regions as they have a thicker fat layer. When confined and under heat stress, they tend to change their behaviour in an attempt to lose heat. Therefore, the objective of this work was to evaluate the enthalpy variation in facilities for growing and finishing pigs in a semiarid region of Brazil. Data were collected every hour via temperature and humidity sensors and enthalpy was then calculated for the experimental period. The average enthalpy values were grouped every 15 days to form a period, totalling six periods of experimental analysis. It was observed that only the third and fourth periods remained within the thermal comfort zone for the enthalpy index, which is between 60.44 and 68.61 kJ.kg-1 dry air. In the remaining periods the average assessed enthalpy values were outside the thermal comfort zone, reaching minimum and maximum values, of 49.75 and 75.06 kJ.kg-1 dry air, respectively.