Heifer Development and Methods to Increase Herd Fertility
STILLWATER, Okla. (Oct. 9, 2014) — During recent years of herd liquidation, cull cows have sustained beef supplies. Now, with U.S. beef cow numbers at their lowest ebb since 1952, cattle feeders are concerned. They are concerned about the future supply of feeder cattle, or a lack thereof. Many have added their voices to the cry for rebuilding of the nation’s cow herd through retention of more heifers for breeding. Rick Funston thinks it will take more than that.
Rick Funston doesn’t dispute the need to grow the herd, but he believes the overall reproductive performance of beef cattle must improve.
Speaking at the Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium hosted Oct. 8-9 in Stillwater, Okla., Funston noted how considerable acreage that once produced forage for cows has transitioned to row-crop production and other uses. The University of Nebraska researcher and extension specialist questions whether remaining forage acres will support a return to former cow numbers.
Funston doesn’t dispute the need to grow the herd, but he believes the overall reproductive performance of beef cattle must improve. Rebuilding herds with females capable of greater longevity would help. Funston told the conference audience that systems to develop replacement heifers can influence reproductive performance for the long term. He questioned the logic behind applying systems that develop heifers in confinement, utilizing diets containing large amounts of grain, and then expecting those heifers to spend the remainder of their lives foraging.
Funston shared results from research conducted with cattle from Nebraska’s Gudmundsen Sandhills Laboratory (GSL). The GSL work, utilizing forage-based systems, challenges the traditional recommendation calling for heifers to be grown to target weights at breeding of approximating 65% of their expected mature weight.
“A heifer weaned at 500 pounds never has to gain more than a pound and a half per day, even to reach the traditional target, but I’d argue that she doesn’t need to be that heavy,” stated Funston, explaining how acceptable results have been achieved when heifers were developed to about 55% of mature weight, or less.
Funston believes heifers developed with feedstuffs similar to those they will consume as mature cows will have earned their way into the breeding herd. He reported that forage-system-developed GSL heifers examined the week previous to the conference had posted a pregnancy rate of 85%.
“I wouldn’t want it any higher than that,” said Funston. “The heifers that made it are better-suited to be cows because of how they were developed.”
Funston said forage-system-developed heifers bred to calve early in the calving season are more likely to continue calving early and stay in the herd longer. To select for longevity, he also favors choosing replacements from among early-born daughters of the oldest cows in the herd. While some might argue that replacement heifers should represent the freshest genetics in the herd, Funston prefers daughters of cows that have proven they fit the environment.
Even if producers do not use artificial insemination, Funston believes estrus synchronization for natural service should be considered. It is another way to promote prolonged reproductive performance.
“Females that are born early in the calving season, and breed early, are likely to stay in the herd longer and raise more total pounds of weaned calf during their lifetimes,” stated Funston.
Funston spoke during Thursday’s session focused on replacement-heifer development. Visit the Newsroom at www.appliedreprostrategies.com to view his PowerPoint, read the proceedings or listen to his presentation.
Comprehensive coverage of the symposium is available online at www.appliedreprostrategies.com. Compiled by the Angus Journal editorial team, the site is made possible through sponsorship by the Beef Reproduction Task Force.
Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.