Researchers at the University of Wisconsin have found that shortening dry periods has a positive impact on reproduction during the subsequent lactation — at least for older cows.

In a recent study on a commercial 3,000-cow dairy, data show that older cows (greater than third lactation) with a dry period of 34 days (versus 55 days) had a shorter time to first ovulation, which reduced the number of anovular, or non-cycling, cows and improved fertility. In addition, the data indicate that the number of anovular cows at 70 days in milk was more than two-fold higher than for those in the longer dry period, and median days open tended to be fewer for cows on the shorter-dry-period treatment.

The research was published in the JulyJournal of Dairy Science.