Professor Robert Collier, dairy specialist at the University of Arizona discusses the dairy issue, saying “Increase in temperatures are likely to reduce milk yields and slow weight gain in dairy cows. The projected increase in temperatures would negatively affect operations, since production costs would increase with reduction in milk and meat production.”
Last year an interesting research in the U.S showed that the cows were happy in northern California and not in Florida, where the mercury touches soaring levels. “We know a stressed out cow is not a profitable cow, so we want to keep them as cool and stress free as possible”, talks farmer, Curtis Martin.
“You see, as the temperatures rise, we have noticed loss of appetite, lethargy, and panting in our cattle which then all spells less milk and we lose out on business majorly”, he added.
Collier here explains, “Cows are actually panting animals, and when they are heat stressed their respiratory rates can go from a standard 35-50 breaths per minute, to 120-140. And when they are panting that much, they don’t want to eat, which obviously results in less milk. In addition to the milk production issue, cows experiencing heat stress tend not to conceive as easily, which then leads to milk production problems.”
Milk production due to climate change will vary across the U.S., since there are significant differences in humidity and how much the temperature swings between night and day across the country. Where the climate is humid and the night time temperature doesn't change much, milk production begins to drop than in the drier climate.
The research could be valuable to farmers who are looking to evaluate the cost and effectiveness of methods for keeping cows cool and those who are looking to expand the dairy business. “These farmers could now make decisions based on climate”, said economist Yoram Bauman,
He further suggests that the research and data based on such issues should be freely available so that farmers can look up their areas and find out how the climate may affect their cows.