As things heat up, don’t let your profitability go down. Research shows that cooling cows during their dry period can keep the milk coming for months to come. “By cooling dry cows, we will definitely get more milk in the next lactation,” says Bruno Amaral, dairy nutritionist with Purina Animal Nutrition.
Research from the University of Florida indicates an advantage of 11 to 12 pounds more milk on average for cows that were cooled with fans and sprinklers during their dry period compared to those that were only provided shade. This increase in daily milk production was measured for a period of 30 weeks post-calving, over the course of three years.
Amaral notes that the milk production response to cooling is impacted by the level of intensity of heat stress, as well as duration and abatement strategies. However, even in a milder climate with fewer heat-stressed days, milk gains from cooling stand to be reaped.
“Would we expect the same thing in Wisconsin (versus Florida) year after year?” Amaral asks. “Maybe not 10 pounds, but probably six to eight pounds.”
How do I know if my cows are cool enough?
Amaral suggests monitoring respiration rates to gauge the level of heat stress a cow is experiencing. He looks for a rate of less than 75 breaths per minute.
Rectal temperature is another method that can be used, but it is a less accurate one because cows’ temperatures tend to run a little higher than normal during warm weather.
Which cows need to be cooled?
“In the best-case scenario, we will cool all of the cows on the farm,” Amaral says. “But if that is not the situation, it brings up opportunities to re-evaluate where we are going to get the most out of our cows to improve profitability.”
Lactating and fresh cows are certainly the priority, but if resources are limited, he leans toward cooling dry cows before late lactation cows.
“Late lactation cows are not producing as much milk anyway,” he adds. “I would invest in my dry cows to make sure they are starting their new lactation on the right foot.”
Are there other benefits to cooling dry cows?
Research on the calf side is also showing that a cooled dry cow may give birth to a healthier, heavier baby. Studies imply that these calves have stronger immune systems and are better able to fight infections.
Further, cows calving during a period of heat stress typically give birth one week earlier, resulting in a lighter-weight calf. This means there is more catching up to do to hit growth and development marks on time, such as doubling birth weight by weaning.
Cooling methods include fans, sprinklers, soakers and shade, or a combination of these things. Even providing just one of them is a benefit over nothing at all.
“Anything you do to provide cooling to the cow will help,” Amaral says. PD
Peggy Coffeen
Editor
Progressive Dairyman
