Higher cattle prices have in­­centivized cattle farmers to start rebuilding the cattle herd in the United States, experts said last week at the cattle industry convention in San Antonio. But try as they may, there are forces beyond farmers’ control that will affect how fast they are able to rebuild the national herd.

The 2014 calf crop was up one-half percent in the U.S. Department of Agriculture’s (USDA) cattle report. This was above analysts’ expectations going into the report, noted Derrell Peel, professor of agribusiness at Oklahoma State University.

“Weather obviously has an impact on calving percentage, but so do...