By Zach Myers, Jonesville, N.C.
Myers Dairy, in the Appalachian foothills, is home to 830 Holsteins and 700 replacements.
A comfortable cow makes more milk. I strive to keep our cows as comfortable as possible.
North Carolina is known for its temperate climate. However, we are far enough south to have some miserable summers but still far enough north to have some snow and ice to deal with as well. We don’t have the extreme cold of the upper Midwest and New England, nor do we have the length of high heat and humidity that the extreme South has.
North Carolina is a great place to milk cows eight to nine months out of the year. The duration of the cold weather we deal with doesn’t normally present many problems, but the three to four months of summer can be challenging.
As we all know, heat abatement is crucial to maintaining production and reproductive performance in the summer months. The best way to keep cows cool is by moving the air and using water.
We have been using fans in our operation since I can remember. We added misters to the fans 20-25 years ago before it was a common thing to do. It was a good concept at the time. If you cool the air down around the cows, then your cows will stay cooler. This did help to maintain a higher production level through the summer than fans alone, but reproductive performance was still not much improved.
Five years ago, with newer research and technology available, we changed from the theory of cooling the air around the cow to cooling the cow herself. We accomplished this by removing the misters from the fans and installing a more programmable sprinkler system above the feed bunk and in the holding area of the parlor. I have the fans come on when the temperature reaches 64°F. At 70°F the sprinklers come on for one minute, wetting the cow every 10 minutes. When the temperature reaches 80°F, the sprinklers will come on for one minute every six minutes.
By evaporative cooling, my cows are staying much cooler now than before. Instead of a 20 lb./cow decrease, we have only an 8 lb. to 10 lb./cow production decrease.
Just as important has been the increase in the reproductive performance of the cows. We are still able to get cows pregnant in the summertime. Prior to installing the sprinklers, it was not infrequent to only get two or three new pregnancies in a week, sometimes none. I now typically get double-digit new pregnancies every week and less open cows on re-check.
With more consistency in reproduction comes more consistent cow numbers in the milking herd. We don’t have the swing in lactating cow numbers that we used to have. Keeping cows cooler in the summer allows them to go into the cooler months healthier, which certainly does not hurt production or reproduction.