Virgin heifers should be the easiest animals to get pregnant on your farm. Apply tail chalk, watch for it to rub off and then breed ... right? But what about the ones that never seem to come into heat?
"Out of 100 heifers we always seem to have one or two that do not come into heat within the first 22 days of entering the breeding pen," says DCHA South Central Director Vance Kells of Circle Bar Heifer Ranch in Satanta, Kan.
There are a number of reasons why a heifer just doesn't seem to come into heat, Kells explains. The heifer might be sick or was sick in the past, her reproductive organs may not be fully developed or she is a freemartin. And if there are any bulls on the farm, you will also want to rule out that she is pregnant by a bull that got out a couple months back.
Fortunately, there are also a number of great synchronization programs available to help heifers come into heat.
"We use all of these on our heifer ranch," Kells says. "It just depends on how much help the heifer needs." Here is his advice:
- Give a prostaglandin shot. If it has been at least 7 days after a heifer's last cycle, she should come into heat within 72 hours.
- Give a shot of GnRH and follow that with a shot of prostaglandin 7 days later.
- Give a GnRH shot on day 1, another GnRH shot on day 7 and prostaglandin on day 14.
- Insert a CIDR (a progesterone-releasing insert) in conjunction with GnRH on day 1 and then give a shot of prostaglandin on day 7. Watch for heat. Breed if you see a heat or use timed-AI at 72 hours after the prostaglandin shot.
Make sure your herd veterinarian is involved in the decisions regarding your reproduction program and for help with pregnancy detection following estrus synchronization and AI. For guidelines covering breeding and pregnant heifers, review DCHA's Gold Standards II, DCHA's production and performance standards established for Holstein heifers, from 6 months of age to freshening.
"We do a vet check every Monday and our veterinarian ultrasounds the ovaries looking for follicles or a developing corpus luteum," Kells says.
Don't miss Vance Kells' virtual tour of Circle Bar Heifer Ranch at the 2012 Dairy Calf & Heifer Conference, March 20-21, in Visalia, Calif., sponsored by Pfizer Animal Health.
Source: Dairy Calf & Heifer Association