Thermal comfort of pigs housed in different installations

Abstract

In an intensive production system, the environment directly influences the comfort and welfare of pigs. Animals under heat stress may exhibit behavioural changes and changes in physiological parameters, such as increased body temperature, respiratory and cardiac movements. The aim of this study was to evaluate the thermal comfort of growing and finishing pigs housed in facilities with different construction typologies. The evaluated pens were: pen with water depth (WDP) and pen with partially slatted floor (SLF). Data on the ambient thermal environment in the pens and in the outside were collected automatically using Hobo dataloggers, model U12-013. This equipment recorded the air temperature, relative humidity of the air and black globe temperature in intervals of five minutes. Subsequently the variables were used in the calculation of the temperature index of the globe and humidity. The physiological responses of the animals were collected: Surface Temperature (ST) and Respiratory Rate (RF). When analyzing the parameters: ST and RF, it was observed that the WDP pen presented a significant difference in all the observed hours, with an increase observed throughout the day, and the SLF pen presented a difference at 9:00 a.m. presenting a lower value than the other schedules evaluated. The BGHI inside the pens showed average values in the hottest period of the day slightly above what is recommended for adult pigs. Both facilities during the hottest time of the day demonstrated a similar trend in relation to the evaluated variables, so it was concluded that both pens provided the same conditions of thermal comfort for the animals.