Breakthrough Could Revolutionize Dairy Cattle
A new Cornell-led study funded by a Foundation for Food & Agriculture Research (FFAR) Seeding Solutions grant has found a nutrition-based solution to restore milk production in heat-stressed cows, while also pinpointing the cause of the decline. This study’s breakthroughs will inform further research that could reveal how different feed additives or changes to the staple diet of cows across the U.S. can sustainably increase milk production, even as temperatures continue to climb. Currently, sprinklers and fans are the primary ways used to mitigate heat stress on cows, but these strategies consume water, burn fossil fuels and only restore about 60% of milk production.
Heat-Stressed Dairy Cows Develop “Leaky Gut”
It was previously known that heat stress causes cows to eat less, accounting for 30-50% of the drop in milk production. The study, published August 2, 2022, in the Journal of Dairy Science, demonstrated that the remaining decline in milk production in heat-stressed dairy cows is caused by increased gut permeability, or “leaky gut.” Occurring in as little as three days, the condition is caused by bacteria and other material “leaking” through weakened parts of the intestinal wall.
In this study, researchers also found that milk production can be partially restored by feeding the cows organic acids and pure botanicals, which normalized gut permeability and increased feed intake and milk production, restoring about three kilograms of milk per day. The cows also exhibited evidence of increased nitrogen-use efficiency, which means less nitrogen – a potential climate pollutant – is excreted into the environment.
Importance of Breakthrough
The demand for dairy products and milk globally is expected to increase 57% by 2050. However, rising temperatures are compromising the American dairy industry’s ability to meet these demands because a cow’s milk production can decline up to 70% in warm weather. Holsteins, by far the dominant breed in U.S. dairy farming, begin to suffer heat stress at 75 degrees Fahrenheit. These heat-stressed dairy cows cost the American dairy industry an alarming $1.5 billion annually. Heat-stressed dairy cows also have reduced fertility, are more likely to develop infectious and metabolic diseases and may succumb to premature death.