Submitted to: Livestock Environment International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 8/19/2008
Publication Date: 12/1/2008
Citation: Brown Brandl, T.M., Nienaber, J.A., Hahn, G.L., Eigenberg, R.A. 2008. Analysis of meteorological parameters of different extreme heat waves. In: Proceedings of the Eighth International Livestock Environment Symposium, 849-855. Iguassu Falls, Brazil. Interpretive Summary: Periods of hot weather have caused death losses in beef cattle feedlots and dairies in regions of cattle producing areas of the world. Weather data (temperature, humidity, wind, sun intensity) was compared from two weather events that resulted in cattle deaths. The two time periods that were closely analyzed included July, 1999 in northeast Nebraska, and July, 2007 in north central South Dakota. Analysis of the 1999 and 2007 heat stress events identified factors that contributed to the severity of a heat stress event as: 1) a preceding cooling period of a few days, 2) recent rainfall, 3) two or more consecutive days of hot weather, and 4) high nighttime lows.
Technical Abstract: Heat waves have caused severe losses in beef cattle feedlots and dairies in different areas of the cattle producing areas of the world. A comparison of climatic conditions that have resulted in cattle deaths has been completed. Analyses of lethal heat waves in northeast Nebraska in 1999 and north central South Dakota 2007 were analyzed. Factors of temperature, humidity, wind speed and solar radiation dominate the impact that local climatic conditions have on livestock. Based on the analysis of these two heat waves, it appears that the following factors contribute to making an extreme event: a preceding cooling period of a few days, antecedent rainfall, two or more consecutive days in the Danger or Emergency categories as calculated by the THI or RRest, and limited nighttime cooling (THI>72).