DES MOINES, Iowa (AP) — Iowa farmers are being urged to watch their cattle for signs of stress as the heat builds across the Midwest. The Iowa Cattlemen’s Association says cattle could be at risk with temperatures around 100 degrees on Wednesday, Thursday and Friday. CEO Matte Deppe says cattle rely on respiration more than sweating to cool down, which means producers must also consider other means to keep them comfortable. Some suggestions from Iowa State University Extension include clean fresh water, shade and using a higher percentage of feed in the afternoon. If necessary, farmers should begin sprinkling cattle with water if there are signs of heat stress. Officials say producers who use fans or water on their cattle should continue to use the process until the heat wave breaks.