There are more than 4600 dairy farms across New York State,¹ making the state the fifth-largest milk producer and the number one yogurt and cottage cheese producer in the U.S. Dairy farming generates nearly half of New York State’s total agricultural receipts.^2,3

Heat Stress in Dairy Cows

High temperature and humidity levels can lead to heat stress in dairy cows.⁴ Mild heat stress starts at around 72°F with 50% humidity, but high-producing cows can become heat stressed at temperatures as low as 65°F.² Mild heat stress can cause a 10% decrease in milk production, with severe heat stress decreasing milk production by over 25%. Other results of heat stress include lameness, hoof ulcers, lethargy, and even death.⁵

Modifications to agricultural building design and systems can help alleviate dairy cow heat stress.⁶ One approach is to provide shade without crowding, leaving about 40 square feet per cow. Ventilation through natural or mechanical means is another method of heat reduction. Cows can benefit when farmers replace the air in the barn 60 to 90 times per hour with a velocity of 5 to 10 miles per hour during hot weather. To do this, many farmers use large box fans mounted above free stalls and feed alleys.⁷ Sprinklers and misters can also promote evaporative cooling.

While the benefits of these cooling strategies in New York State do not yet outweigh the costs, projections show that they will do so by the middle of the century.⁸