Ovsynch Protocol (Part One)
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Jan. 27, 2005
With Ray Nebel,
Extension Specialist and Professor of Reproductive Management,
Virginia Tech
This week we are with Ray Nebel, who is taking on a position with Select Sires here soon, and is currently Extension Specialist and Professor of Reproductive Management at Virginia Tech. We are talking this week about the Ovsynch system.
Yes, Bill. The problem has been, for years, estrus detection and our lack of being able to catch cows in heat. We still need to breed cows, and breed them in a timely manner. In 1995, researchers from the University of Wisconsin came up with a procedure to synchronize cows and breed them, time breed them, which has been very, very successful. It has been coined as the term Ovsynch. In the last ten years this has been a procedure that has been widely accepted.
Why do you think Ovsynch is the way to go?
Ovsynch has really revolutionized our A.I. breeding because it allows you to set up when you want to breed cows and it puts you in control. Up until this point we were at the mercy of the cow to determine when she wanted to be bred, but in the new modern dairies we have more cows so there is less labor per cow. With confinement, the cows are on concrete almost 24 hours a day, so foot problems become a problem. With production there is an antagonistic effect from higher milk production. The cows express fewer estrus signs, and it has been more and more difficult to catch cows in estrus for A.I. So the advent of Ovsynch has really allowed us to become in control of the breeding program.
Take us step-by-step through the Ovsynch protocol.
What is nice about Ovsynch is that it is a pretty quick-and-easy, as well as inexpensive, procedure. There are three hormone injections. The first hormone in Ovsynch is given at a random stage of the estrus cycle so we don’t know where the cow is, as far as cycling. If she is early diestrus or mid-cycle, or anywhere in the estrus cycle, that injection is Gonadotropin Releasing Hormone (GnRH). Then, one week later (seven days later) we give an injection of prostaglandin. The prostaglandin causes regression of the corpus luteum (CL) that was formed after the initial injection seven days earlier. To finish it off, the standard protocol calls for giving the second Gonadotropin Releasing Hormone (GnRH) 48 hours later. At this time, what it does is cause the beginning of the ovulation of the follicle. Then, we recommend A.I. breeding somewhere between 12 and 20 hours after the injection of (GnRH).
And you are finding this is proving to be successful?
In lactating dairy cows, first service, we can get an acceptable level, which is between 26 and 38 percent, and that varies depending on the nutrition and conception or fertility levels in the herd itself. I don’t get concerned if we are getting somewhere between –- it seems like a large range, I know -- but 26 and 38 percent. If it is somewhere in there, then I feel as though the procedure is working, and we are getting acceptable results.
Is it your impression, in the field, that people are turning more and more to this Ovsynch system?
I think so, and I think probably it was used first on problem cows as a last-ditch effort to try to get them bred. Those that had been inseminated on estrus, and other different manners. So when Ovsynch first came out ten years ago, of course, there was always a little bit of skepticism, or "is it going to work on my farm?". So they picked a group of cows to try it on, and a lot of times those were probably the worst group of cows to try it on. It was the ones that were problem breeders. Today, more and more, I think we see it implemented on first service across the boards. We see very acceptable results. So, implementation is definitely increasing.
Ray Nebel, Extension Specialist and Professor of Reproductive Management at Virginia Tech.
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