A University of Nebraska-Lincoln project is testing whether artificial insemination of beef heifers with fresh semen pooled from three bulls gives higher pregnancy rates than frozen or single-sire semen, The Fence Post reports.

The work runs at the Panhandle Research, Extension and Education Center research feedlot, leased by Bryan Palm of 2Bar Ranches, with Nebraska Extension beef reproductive specialist Rick Funston. It covers 339 Angus heifers bred with semen from three unrelated Angus bulls, plus 534 Angus crossbred heifers at the Kelly ranches north of Sutherland.

"Previous research suggests that using multi-sire semen may increase pregnancy rates by roughly 9 to 11.5 percent, potentially because combining sperm from multiple bulls could improve overall semen quality," Funston said. The study also tests whether fresh semen outperforms frozen, on which past results have been mixed.

In the first of three years, heifers bred with fresh pooled semen showed pregnancies up by almost 11%. After weaning next year, the calves' DNA will be tested for parentage to show which bulls contributed most.

For Palm, who is building a closed herd, every point matters: "Every percentage rate we can get better in our AI is money ahead for us." He noted that fresh semen must be collected and delivered within 48 hours, unlike frozen stock. The report is by Chabella Guzman of the Panhandle centre.

Photo: Krista Lundgren/USFWS / Wikimedia Commons (Public domain)

Source: The Fence Post