Just as the summer grilling season heats up, beef supplies across the country are down, meaning it might cost a little more to host that backyard party.

In fact, the number of beef cattle in the United States is reportedly less than 30 million — the lowest number since the early 1960s. And when numbers go down and feed prices go up, consumers end up paying more at the grocery store.

“In the interest of telling the whole story, productivity has also increased since that time,” said University of Kentucky College of Agriculture economist Kenny Burdine. “But, the combination of fewer cattle over the past several years and generally strong export markets has left beef supplies relatively tight.”

UK Beef Specialist Les Anderson explained that for the past several years, many beef producing areas of the United States have experienced drought situations and increased feed costs.

“Drought affected vast segments of many of the beef producing states, and that led farmers to reduce the number of cattle they produce,” he said. “Also, many feed costs have been markedly higher during the drought periods, so ranchers have been reluctant to hold onto their cattle, simply because it costs too much to feed them.”

Because of those conditions, Burdine said the industry has seen sizeable decreases in cattle inventory in many areas — most notably the Southern Plains.

“Many areas have been impacted by the weather, including the Southeast,” he said. “Another factor worth noting is that we are seeing a considerable conversion of pasture and hay ground to row crop production.”

Even in Kentucky, beef cow numbers are down, about 15 percent from January 2007 to January 2013, but beef specialists expect the industry in the state to hold steady.

“Kentucky farmers have leased land, previously used for pasture, to crop farmers because of high prices being paid for land leases,” said Roy Burris, UK beef specialist at the UK Research and Education Center in Princeton. “But, a lot of land here is not suitable for cropping, so the best use for that land is to continue grazing. Barring any severe droughts, I really think cattle numbers in Kentucky will hold steady.”