Effects of heat exposure on water metabolism and passage in sheep

Katoh, K.; Buranakarl, C.; Matsunaga, N.; Lee, S. R.; Sugawara, T.; Sasaki, Y.

doi:1989.2.2.91

Article

Ruminant Nutrition and Forage Utilization

Asian-Australasian Journal of Animal Sciences 1989;2(2): 91-97.
https://doi.org/10.5713/ajas.1989.91 Published online June 1, 1989.

Effects of heat exposure on water metabolism and passage in sheep

K. Katoh, C. Buranakarl, N. Matsunaga, S. R. Lee, T. Sugawara, Y. Sasaki

Abstract

The present experiment was carried out to investigate the effects of heat exposure on water metabolism and the passage of indigestible particles in sheep. Water intake, respiratory rate, rectal temperature and pH of ruminal fluid and urine were significantly higher (P<0.05) in the hot environment (32째C) than in the control environment (20째C). Urine osmolality and blood volume were increased, while glomerular filtration rate was decreased, in the hot environment. The liquid flow rate from reticulo-rumen and the excretion of indigestible particles of specific gravity 0.99 (but not 1.27 or 1.38) were increased in the hot environment. From these findings, it is suggested that an increased water intake evoked by heat exposure might affect the flow rate of digesta in sheep.

Keywords: Water Metabolism; Passage; Sheep; Indigestible Particles; Heat Exposure