There is a freight train of new management tools headed for U.S. dairy farms, and it’s aiming straight for the heifer breeding pen, says Pat Hoffman, professor of dairy science based at the University of Wisconsin’s Marshfield Research Station in Marshfield, Wis.
“Heifers are a new horizon for herd improvement with genomic testing,” says Hoffman. “Cows are already cows, so testing them doesn’t allow us to make informed management decisions about them the way we can with heifers.”
Dick Wallace, senior dairy technical service veterinarian with Zoetis Animal Genetics, says a first-calf heifer needs to perform as a productive member of the herd for more than one lactation to compensate for the cost of raising her.
The use of sexed semen and embryo transfer, along with improved reproductive programs, has left many dairies with far more heifers than they need to maintain their herd size. Couple that fact with today’s high feed prices, and it is easy to see why being selective about which heifers to raise could be beneficial to a herd’s bottom line and its genetic advancement.
“The decisions we need to make about every heifer are (a) whether she is needed in the herd, and (b) if she fits the genetic goals of the herd,” says Wallace. “If the answer to either question is ‘no,’ then genomics can help determine other routes for her than the breeding pen.”
Wallace works with herds on the application of CLARIFIDETM Dairy Genomics Test, a 6,909-marker (6K) panel that delivers genomic predictions for as many as 30 production, health and type traits, as well as nine composite indexes. He advises producers to test heifers as early in their lives as possible to make rapid decisions regarding their futures, suggesting that the results could send heifers down one of several paths. A herd plan might look something like:
1. Lowest 10 to 15 percent – sell for dairy or beef.
2. Next 20 to 40 percent – use as recipient animals for embryo transfer, allowing them to enter the milking herd but not transmit their genetics.
3. Next 20 to 40 percent – breed to sexed semen.
4. Top 5 to 10 percent – enroll in embryo transfer programs.
While those percentages will vary among herds, Wallace says the structure helps producers manage heifer inventories with confidence that they are continuously improving their herds. Another strategy some herds are employing is breeding a percentage of their low-end genomic animals to beef sires. “This approach captures some premium value for the calves, and removes the temptation to keep lowergenomic animals in the herd,” says Wallace.