Milk
US
Put simply, hot cows give less milk and many US farmers could struggle to help their cows stay cool and to find affordable water for feed production and livestock in coming years.[1] A lactating dairy cow drinks up to 50 gal. (190 L) of water daily and much more when she is heat stressed.[2] When heat stressed they drink and respire more but eat less, which lowers milk production. Some heat-stressed cows produce milk with less protein, lactose, and fat. The cows’ immune systems can also weaken in hot conditions and their fertility rates drop.[3] Heat stress effects can last weeks to months.
References:
[1] USGCRP, “Fourth National Climate Assessment” (U.S. Global Change Research Program, Washington, DC, 2018), https://nca2018.globalchange.gov/chapter/10.[2] “Drinking Water for Dairy Cattle: Part 1,” MSU Extension, accessed March 16, 2021, https://www.canr.msu.edu/news/drinking_water_for_dairy_cattle_part_1.
[3] Nardone et al., “Effects of Climate Changes on Animal Production and Sustainability of Livestock Systems.” Livestock Science 130, no. 1–3 (May 2010): 57–69. https://doi.org/10.1016/j.livsci.2010.02.011.
