Heat stress can have a huge impact on unborn calves that reaches well into their adulthood. “Cooling is pretty important for the fetus,” says Geoff Dahl, a dairy physiologist with the University of Florida.
Source: Dairy Herd Management, March 30, 2017.
Unborn calves of heat stressed dams will have lower birth and weaning weights, and might produce 2,500 lb. to 3,000 lb. less milk in their first lactation.
See also: Time to Think Heat Stress Again