Select Sires

Systematic Rebreeding Programs
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Aug. 21, 2003
With Mel DeJarnette, reproductive specialist,
Select Sires Inc.

Mel, in this week’s Reproductive Moment you are talking about re-synchronization programs.

Yes, in prior segments we’ve talked about the advantages of programmed breeding systems such as Ovsynch and targeted breeding to ensure that every cow receives their first insemination in a timely manner after calving. With the adoption and adherence to these programs, days-to-first-service is basically eliminated as a limiting factor to reproductive efficiency. When appropriately administered in well-managed herds, we can expect to get 30 to 35 percent of the cows to conceive at first A.I. using Ovsynch. That still leaves 65 to 70 percent of the herd that are open. How long it takes us to identify these open cows and get them re-bred now becomes a major limiting factor to reproductive performance. Thus, many producers are beginning to realize significant benefits from the implementation of systematic re-breeding programs.

The simplest re-breeding programs are to simply give prostaglandin or to restart Ovsynch on open cows the day of the pregnancy check. Compared to rectal-palpation, use of ultra-sound may allow us to trim five to seven days off this re-breeding interval and provides a greater degree of accuracy in very early pregnancy diagnosis. This increased accuracy ensures that the right cows are getting re-synchronized and reduces the incidence of accidentally inducing abortions. An additional seven days to Ovsynch re-breedings can be gained by giving all inseminated cows GnRH seven days before vet check. Pregnant cows then receive no further treatment, while the open cows continue on the Ovsynch protocol and are rebred at fixed time three days later.

However, Ovsynch re-breeding, with or without ultrasound, is still no match for the return on investment available through timely re-insemination of cows at their normal return to estrus 18 to 24 days after A.I. This job also just got easier with the recent FDA approval of the EAZI-BREED™ CIDR® for use to synchronize these returns to estrus in lactating dairy cattle. This vaginal insert, which contains the natural pregnancy hormone progesterone, is administered to cows 14 days after insemination and is removed seven days later, or day 21 of the cycle. Most open cows will then exhibit a synchronized return to estrus over the next two or three days. In contrast to the use at first service in beef cows, it is important to remember NOT to use LUTALYSE® or any other prostaglandin when re-synchronizing groups of cows of unknown pregnancy status. No matter how you do it, the key to profitable reproductive management is to identify and re-inseminate open cows as soon as possible. For more information on systematic breeding or rebreeding programs, contact your veterinarian or your local Select Sires Reproductive Solutions™ specialist.

®CIDR is a registered trademark of InterAg, Hamilton, New Zealand
®LUTALYSE is a registered trademark of Pharmicia and Upjohn Company, a division of Pfizer Inc.
™EAZI-BREED is a trademark of InterAg, Hamilton, New Zealand
™Reproductive Solutions is a trademark of Select Sires Inc.

Select Sires Inc., 11740 U.S. 42 North, Plain City, Ohio 43064 / Phone: (614) 873-4683 Fax: (614) 873-5751