Milk production is roughly equal between the “traditional” dairy states of the Midwest and Northeast and the “modern” states.

A generation ago, California surpassed Wisconsin, “America’s Dairyland,” as the No. 1 milk-producing state, a shift that exemplified the growing prominence of dairy farms in the West and Southwest with huge herds producing a flood of milk. The competition is more equally balanced now, said an analysis on Monday. Milk production is roughly equal between the “traditional” dairy states of the Midwest and Northeast and the “modern” states.

“Traditional and modern dairy states have grown in very different ways,” wrote agricultural economists Jared Hutchins and Joe Janzen of the University of Illinois at the farmdoc daily blog. “Most production growth in traditional dairy states comes from rising milk yield. Modern dairy states have grown production by increasing both milk yield and the total number of cows.”

Since 2010, traditional states have increased milk yield per cow by 18 percent, compared to 8 percent in the modern states. “One possibility is that traditional dairy states are investing less in growing their cow numbers and more in better management, enhanced milking technology, and more productive genetics,” wrote Hutchins and Janzen. Zoning and environmental regulations also may be a factor, they said.