For example, you can reasonably expect to gain about 4.8 pounds of milk per day if you cool high-producing cows at 68 degrees F rather than at 72 degrees F. Even if you gain half of that, for 100 cows, you’re still increasing daily production by about 200 pounds.
Using a milk price of $17 per hundredweight for those 200 pounds and a feed cost of $14 per cwt., your income over feed cost is $6 (34-28=6).
Using a variable cost of $0.14 per cwt. and assuming each cooler would cool 10 cows, the total cooler variable cost is $1.40, or a cost of about $0.045 per cow per day for 100 cows. Of course, you’ll need to use figures from your operation to determine whether this makes financial sense for your dairy, but these numbers give you the general idea.
In addition, Collier notes that cooling cows at 68 degrees F, or even 65 degrees F, has positive effects on reproduction.
“Since high-producing cows are generally early-lactation cows, these are the animals you’re trying to breed,” he notes. “It makes sense that cooling them would have a reproductive benefit.” Additional research currently under way should bring some more definitive answers as to the total reproductive impact.
In the meantime, these findings mean you have the potential to target cooling strategies within your facilities — or at least begin thinking about how you can improve your cooling program. For instance, you can cool your high-producing cows down to 68 degrees F, but then use the original THI for their lower-producing herdmates to further reduce cooling cost.
In addition, researchers are working to learn more about how to best accomplish this cooling. That is, how should you time your cooling strategy. “If we started cooling early in the morning, some cows stayed away from feed,” Collier notes. “So, should we wait until later in the day? Or should we wait until it hits 68 degrees F to begin cooling? These questions all have to be worked out.”
And, Collier and his colleagues are working on a new THI chart for high-producing cows that should be available sometime later this year.
Therefore, while not all the answers are yet available, the concept of cooling high-producing cows at a lower temperature looks like a real opportunity for dairies, he concludes.