The Influence of Thermal Radiation on Body Temperature, Cardiorespiratory Activity and Meat Productivity of Growing Pigs Kept at a Constant Temperature of 30°C

Abstract

The influence of a radiant heat load upon growing pigs kept at a constant temperature of 30°C was studied using 30-40kg Landrace piglets fed ad libitum. Four piglets were used for Experiment I, and six for Experiment II. In each experiment, the piglets were divided into two groups; one group was kept at a constant temperature of 30°C as the control group, another at the same temperature but was subjected to a load of radiant heat (500kcal/m²•hr) using an infrared heater for 6 hours a day. The average rectal temperature of the control group was 39.8°C, while that of the radiated group was 40.7°C, showing a significantly higher temperature(P<0.01). The respiration rates for the two groups were 110 and 164, respectively (P<0.05). There was no significant difference in the heart rate between the two groups. Daily weight gains were poor in both groups, the latter being significantly poorer (P<0.05). The feed intake was similar in both groups. It was concluded that thermal radiation added to the environment at a constant temperature of 30°C did exert adverse effects upon growing pigs.