The USDA Livestock Slaughter report Friday morning confirms a trend toward greater slaughter numbers in recent months. But the size of the national herd continues to grow as well.  

During the first five months of this year, 247,800 dairy cows were slaughtered per month, on average, compared to 231,000 during the first five months of 2010. This morning, the USDA reported that 220,000 dairy cows had gone to slaughter in May, which was a relatively low number compared to 264,000 in January and 268,000 in March.

Meanwhile, cow numbers continue to increase. According to the latest USDA “Milk Production” report on June 17, there were 8.45 million dairy cows in the top 23 states in May — up from 8.319 million in January 2010.

The apparent contradiction between higher slaughter numbers and higher cow numbers can be explained. It’s due to an abundant supply of heifers, along with beef prices that are high enough to provide a good return on cull cows, says Greg Scheer, dairy analyst for Doane Advisory Services in St. Louis.

On Jan. 1, there were 3 percent more dairy replacement heifers -- those expected to calve during the year -- than there were a year earlier, according to a recent "Cattle" report from USDA.