The Effect of Summer Environment on the Body Temperature and Respiration Rate of Swine

Abstract

Eight pigs weighing from 116 to 183 pounds were used in this study of the effect of exposure to sunlight. Four pigs were of the Poland breed and four pigs were of the Duroc breed. They were divided equally as to sex. These pigs were exposed to sunlight for 15 and 30 minutes on alternate test days. The exposures were made under naturally occurring air temperature and humidity conditions. This study showed that there was no correlation between air temperature or relative humidity and initial body temperature of the pigs. The differences in body temperature rise on different days of 15-minute exposure were statistically significant. The differences in body temperature rise on different days of 30-minute exposure were also statistically significant. The body temperature rise on 30-minute exposure was significantly greater than the rise on 15-minute exposure. The average rise in body temperature for a 15-minute exposure was 0.92° F. and for a 30-minute exposure 1.97° F. The differences between individuals in body-temperature rise during 15 or 30-minute exposures were not statistically significant. The average rise in body temperature of the Poland pigs for both 15 and 30-minute exposures was significantly higher than for the Duroc pigs. The Poland pigs showed an average rise of 1.13° F. for the 15-minute exposure and 2.09° F. for the 30-minute exposure. The average temperature rises for the Durocs during 15 and 30-minute exposure were 0.72° F. and 1.80° F., respectively. The differences in respiration-rate increase on different days were found to be highly significant. Differences between the breeds in respiration-rate rise were found to exist when exposed for 15 or 30 minutes. This difference between the two breeds was highly significant. During the 15-minute exposure the average respiration-rate rise for Polands was 25.2 respirations greater than the average respiration-rate rise for Durocs. The difference between the pigs of these two breeds was somewhat less during the 30-minute exposure. During the 30-minute exposure the respiration rate rise for the Polands was only 8.5 respirations per minute higher than for the Durocs. Individuals within the two breeds showed variable changes in respiration-rate rise. These individual differences were highly significant. The average rise in respiration for the 15-minute exposure was 49.8 respirations and for the 30-minute exposure 80.8 respirations. No significant difference was found to exist between the sexes in respiration-rate rise. A significant positive correlation existed between the body temperature and respiration rate rises during the 15-minute exposure. The average temperature rise was 0.92° F. and the average respiration-rate rise was 49.6 respirations per minute. However, during the 30-minute exposure there was not a significant correlation between temperature and respiration rate rise. The average temperature and respiration rate rises for 30-minute exposure were 1.94° F. and 81 respirations per minute. Copyright © . .