Milk production in the top 23 milk-producing states totaled 15.8 billion pounds in March, up 2.4 percent from the same month a year earlier.

Across all 50 states, milk production was up 2.2 percent, according to the “Milk Production” report issued Tuesday by the U.S. Department of Agriculture.

It is the 14th month in a row that milk production has risen on a year-over-year basis.

The number of milk cows in the 23 states was 8.42 million, 93,000 head more than the same month a year earlier and 17,000 head more than February 2011.

Among the top 23 states, Colorado and Arizona showed the highest percentage increase in milk production at 8.6 percent. California, the nation’s No. 1 milk-producing state, was up 3.1 percent. Missouri declined by 3.8 percent.