By Shelby Frink
The researchers found that increasing temperatures from climate change could slightly increase milk production, despite heat stress on the cows.
Dairy cows produce less milk when it’s too hot, said Rigoberto Lopez, corresponding study author and professor of Agricultural and Resource Economics at the University of Connecticut. However, hot temperatures stimulate the growth of plants that cows eat to produce milk.
The loss of milk production through heat stress is offset by an increase in feed production, according to research published in March in the journal Agricultural and Resource Economics Review.
This is because the more cows eat, the more milk they can produce, Lopez said.
This is the first US study to analyze that tradeoff, he said. Another study in Spain came to the same conclusion.
The researchers focused on temperature extremes, Lopez said. “We wanted to see the effects of climate change on cattle.”
Another benefit of a warming climate is that feed production increases over a 10-year span as the growing season lengthens over time, said Chris Laughton, study co-author and agricultural economist at Farm Credit East, a Connecticut financial services network. .
Increased feed production also has economic implications.
Feed is the biggest part of the cost of milk production, Lopez said. Whatever happens to the feed will affect the profitability of the farm.
Feed is a dairy farm’s biggest expense, mainly between rising fertilizer costs and the cost of land to grow it, says Eric Westendorp, a dairy farmer at MOO-ville Creamery in Nashville, Michigan.
The benefits of increased feed production are modest, Laughton said.
According to research, for every 1% increase in 90 degree days, there is a 0.0024% increase in milk production when cows eat supplementary feed.
By 2080, the number of days above 90 degrees will increase 10-fold for northern regions closer to the lake, Lopez said. This includes Michigan and northern New York.
Westendorp hasn’t seen an impact yet, but noted there was a 5-7 pound drop in milk produced by each cow in July and August due to heat stress.
It’s hard to see the true effects of climate change as agricultural efficiency increases with new technologies and changing practices, Laughton said. One of the best ways for farmers to reduce the impact of climate change is to focus on comforting the cows during hot days.
MOO-ville Creamery is a medium-sized dairy farm with 500 cows, but only about 215 are active milk producers while the rest are pregnant or calves, Westendorp said. Farms combat heat stress by fans and protective cloth in the barn and by laying sand for the cows.
The farm hopes to implement the robotic immersion system in the coming summers, Westendorp said. It will use motion sensors to detect the location of the cow before spraying it with water to cool it.
Increasing efficiency can also help reduce the economic impact of climate change, Lopez said. Larger farms are usually the most efficient.
Four milking robots increase MOO-ville’s efficiency by reducing labor costs and increasing milk production, Westendorp said.
They increase daily milk production by 3 to 5 pounds per cow, according to the University of Minnesota.
Only 55 of the 1,206 dairy farms in Michigan used robotic milking machines in 2020, the Michigan Department of Agriculture and Rural Development reports.
Dairy farmers have no reason to worry too much about climate change in terms of heat, Laughton said. The bigger concern is that climate change means that farmers are getting rainfall in a more concentrated way.
That means they have to look at irrigation and drainage technology because they will go through a cycle of having too much water and not enough, “sometimes even in the same season,” Laughton said. This will have a negative impact on feed production.
The study did not focus on the effects of changing rainfall patterns on dairy farms, Laughton said. It will be difficult to measure because there are many variables.