What would you do differently if you knew how severe the summer heat and humidity were going to be? Every summer brings different patterns and severity to heat stress and reproduction affects. I have often heard, “I should quit breeding cows when it gets hot.” This month’s Journal of Dairy Science has an article that looks at that question. A Florida dairy farm extended their voluntary wait period during the summer and then evaluated profitability. The voluntary wait period initially was 60 DIM and they moved it to 83 DIM. While they did see higher conception rates in the delayed voluntary wait period group, this increase did not improve overall reproduction performance and did not affect overall profitability.
That said, there are several ways to minimize the affects of summer heat stress on reproduction and milk production loss:
1. Soak the cows in the holding pen
2. Reduce time and crowding in the holding pen
3. Use fans and sprinklers in the close-up pen
4. Feed cows twice a day to keep feed fresh
5. Step up your fly control program
6. Clean and disinfect water tanks every week
We live in a great climate for growing crops but those conditions are a challenge for cattle. Remember to control the controllables and take the uncontrollable weather off of your list of things to worry about.