Reprinted from the American Red Angus Magazine. Written by Jaclyn N. Ketchum, Cliff Lamb, and Michael F. Smith, Division of Animal Sciences, University of Missouri, and Department of Animal Science, Texas A&M University Efficiency, sustainability, productivity and profitability – these words are used in conversations around the world including among cattlemen. How do cattlemen assimilate these goals into their herd? One way is by implementing a defined breeding season. “Heifers that conceive earlier in the breeding season will calve earlier in the calving season and have a longer interval to rebreeding. Calves born earlier in the calving season will also be older and heavier at weaning,” stated Robert Cushman of U.S. Meat Animal Research Center. He added, “Heifers that calved early in the calving season with their first calf had increased longevity and kilograms weaned, compared with heifers that calved later in the calving season.” Increased longevity and heavie