Geni Wren If cattle country experiences another drought like last year, many of your beef clients may be early weaning calves if forages are in short supply. But can early-weaning of replacement heifers negatively affect future reproduction?
Bob Larson, DVM, PhD, Dipl. ACT, Dipl. ACVPM, Kansas State University, says they shouldn’t have problems if they are managed right.
“I don’t know of any information that would make me think that early weaning would have a detrimental effect on heifer fertility,” Larson says. “If the reason that a producer is considering early weaning is because forage is becoming scarce and calf and/or cow performance is likely to be negatively affected by calf presence on the cow (in the pasture), then I would consider early weaning to be beneficial for managing the heifers to ensure good success to a controlled breeding season.”
But nutrition at this age will be critical. “I would manage early weaned heifers so that they are receiving a good quality forage (and supplementation if forage quality or quantity is limited) that will allow at least 1.5 pounds of daily weight gain,” Larson advises.
“A reasonable target is for almost all the heifers in the group to weigh 60-65% of their mature weight by six weeks to a month before start of the heifer breeding season,” Larson says. “I like to evaluate the body weight, reproductive tract score, and pelvic area four to six weeks ahead of the breeding season to ensure that almost all (80% or more) of the heifers are cycling by the start of the breeding season – and have time to intervene if they do not appear to be on-track for reaching that goal.”
Larson says there is ample time from early weaning until breeding to meet this goal, even if part of that time period includes lower ADG due to forage restrictions.