Environmental Management Research : Recognizing Heat Stress

Recognizing Heat Stress

Pictured below are cattle displaying increasing levels of heat stress. A description of typical behaviors is associated with each level. Vulnerable animals will show stress symptoms early. Varying stages of stress will be evident throughout the herd as environmental conditions become more intense. As more animals display signs of increasing heat stress, action should be taken.

Normal

no signs of heat stress

Stage 1

elevated breathing rate

restless

spend increased time standing

Stage 2

elevated breathing rate

slight drooling

most animals standing in pen and restless

animals may group together

Stage 3

elevated breathing rate

excessive drooling or foaming

most animals standing in pen and restless

animals may group together

Stage 4

elevated breathing rate

open mouth breathing

possible drooling

most animals standing in pen and restless

animals may group together

Stage 5

elevated breathing rate with pushing from flanks

open mouth breathing with tongue protruding

possible drooling

most animals standing in pen and restless

Stage 6

open mouth breathing with tongue protruding

breathing is labored, and respiration rate may decrease

cattle push from flanks while breathing

head down

not necessarily drooling

individual animals may be isolated from herd

_______________________________________

Gaughan, J. B., Holt, S. M., Hahn, G. L., Mader, T. L., and Eigenberg, R. A. 2000. Respiration Rate - Is it a good measure of heat stress in cattle? J. Anim. Sci. 13: 329-332.

Mader, T. L., Davis, M. S., and Brown-Brandl, T. M. 2006. Environmental factors influencing heat stress in feedlot cattle. J. Anim. Sci. 84: 712-719.

Silanikove, N. 2000. Effects of heat stress on the welfare of extensively managed domestic ruminants. Livestock Production Science 67: 1-18.