Longevity, rebreeding and calf survivability are gaining importance as the nation’s cow herd becomes more straightbred. Animal scientists say that is because commercial cow-calf producers have forgotten or ignored hybrid vigor (heterosis). A crossbreeding program can increase lifetime production by more than 20 percent if you design it to capture both direct (individual) heterosis in crossbred calves and maternal heterosis in crossbred cows.
Scott Greiner, Ph.D., an Extension animal scientist at Virginia Tech, explained that the advantage of the crossbred calf is two-fold: an increase in calf livability coupled with an increased growth rate relative to its straightbred parents.
To illustrate the first point, Cathy Bandyk, Ph.D., an animal scientist at Quality Liquid Feeds, Dodgeville, Wis., cited an in-depth multibreed analysis done at the U.S. Meat Animal Research Center (USMARC) in the 1970s. It showed crossbred calves exhibited less death loss and better gains – and, therefore, more pounds of weaned calf – compared to purebred animals.
“Death loss among the crossbred calves was just 5.2 percent, compared to 14.2 percent for the purebred calves,” she said.
Research has shown weaning weights for crossbred calves are 5 percent greater than those for straightbred calves, and yearling weights are 4 percent greater. Roy Burris, Ph.D., an Extension beef specialist for the University of Kentucky, noted that two-breed–cross calves weigh about 30 pounds more at weaning than straightbred calves, and calves averaged about 80 pounds heavier at weaning when they were out of a two-breed–cross cow and a third breed of bull.
Historical data also show consistent performance advantages for crossbred feeder calves and finished cattle, Bandyk added. Again referring to USMARC research, she said the calves of British-based cows and Continental or Bos indicus sires had significantly reduced rates of bovine respiratory disease (BRD).
Frank Padilla, director of member and commercial relations for the North American Limousin Foundation (NALF), has witnessed that better health in the feedyard and said, “That’s why feedyards like buying calves that will have good hybrid vigor. Crossbred steers can show a $45 per head advantage over straightbred steers.”
Commercial cow-calf producers realize even more benefits from crossbreeding when they use crossbred cows because maternal heterosis results in improved cow fertility, calf livability, calf weaning weight and cow longevity. Those cumulative effects increase productivity tremendously, said Bob Hough, Ph.D., executive vice president for NALF.