To strike a balance between grade and gain, implant and marbling levels, the South Dakota State University beef feedlot delays implanting until putting cattle on full feed.
"It's almost become standard operating procedure around here," says Robbi Pritchard, SDSU beef scientists and head of the university's feedlot.
To compare practices, his feedlot team recently divided 650-pound steers into three groups -- non-implanted, estradiol-trenbolone acetate (TBA) implanted at 650 pounds or TBA implanted at 850 pounds.
Implanting increased hot carcass weight, but delaying the implant resulted in a 15% increase in cattle reaching the premium Choice or higher.
SDSU now waits until final diet before implanting calves, and that increases average gains by 20%.
"If they're eating enough to gain 4.5 pounds per day, that boost is .9 pounds," Pritchard says. "When they're only gaining 1.5 lb. per day, in their first week, it's only a 0.15-lb. improvement. That's when it pulls grade out of them: when the implant is going full-tilt and the calories aren't there."
Source: Certified Angus Beef