I've been fascinated for years at the cattle industry spending trillions of dollars promoting the undesirable trait of black haired cattle in hot environments.
Cattle naturally produce excess heat in their rumen, which takes energy to get rid of. They begin to experience heat stress at 70 degrees. Then you fatten them up, put them on dirt/concrete in a feedlot with no shade, and paint them black, and wonder why they might die when it gets hot. Just blame it on the weather.
Of course, you get more for blacks at sale barn, and few humans can think past that check.
Will be interesting to see how many more big death losses before people consider doing something, like offering shade and changing color. Short of dying, heat stress also causes lost production, lower fertility, etc, but that is harder to quantify than the check at the sale barn.
I'm guessing with the pressure of the almighty dollar, the white angus breed died. Trillion dollar industry surely didn't like it.
vetmed.iastate.edu
"Heavy cattle cannot handle heat stress compared to lighter weight cattle. Increased fat deposition prevents cattle from regulating their heat effectively. Solar radiation is a critical component that can lead to death loss from heat stress. Typically, proportionality more black hided cattle die during heat waves then other hide colors. Since cattle rely on respiration as a method to manage heat respiratory function is important."
