The Iowa State University Extension and Outreach Dairy Team’s 2023 Dairy Webinar Series continues Wednesday, July 19 from 12 noon to 1 p.m. CDT. Dr. Jennifer Van Os will discuss heat stress in dairy cows and calves from an animal welfare perspective, including recognizing how cattle tell us they need help beating the heat.
It is not a question of “if” we will have days in Northwest Iowa that cause heat stress in milking herds, but rather, how many days we will have. Heat stress decreases feed intake and milk production, decreases milk components including fat, lowers breeding efficiency and compromises the immune system plus the heat and humidity is a near perfect environment for mastitis pathogens to thrive.
When we think of temperature stress on calves, the common concern is cold, but as temperatures are moving to the 900F mark this week, producers need to remember soaring summer temperatures, hot sun, and high humidity can cause heat stress in calves and heifers just as in the milking herd. Reduced feed intake and increased maintenance energy needs coupled with lowered immunity can lead to poor growth, higher susceptibility to disease, and in extreme cases death.