Select Sires

Insemination in Heifers
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Sept. 2, 2004
With Ray Nebel,
extension specialist and professor of reproductive management,
Virginia Tech

This week’s Reproductive Moment is with Ray Nebel, Extension Specialist and Professor of Reproductive Management at Virginia Tech. This week, Ray, we are talking about insemination in heifers, especially with the timed-A.I. program.

Across the country we have done a good job at artificially inseminating dairy cattle. But in the heifers it is a lot like the beef cattle management in that they are out away from the normal operation and we don’t see them very often. So, artificially inseminating heifers is still a place where we can take advantage of the good genetics. The other big thing there is that our conception rates in heifers are so much higher than what we normally get in cows. Conception rates in cows are somewhere around the mid 30’s. You can see here in heifers we are in the mid 60’s. So we can spend a little bit more money for semen, get a better quality product and get a lot better return because of higher conception rates.

I understand that there is a new procedure that helps with elimination of some of the labor, especially with the timed-A.I. program.

That is a product called CIDR® which is a progesterone device that prolongs the days that our heifers are not active.

Is this government-approved?

CIDRs are approved. They initially were approved for heifers and beef cattle. In May of 2003 they were approved for lactating cows. It has been available for heifers and beef cattle for a little bit more than a year and a half, and for dairy cattle slightly less than that.

What has been the response from your experience, and from what you have heard?

In heifers I really believe using a timed-A.I. program is the best way to maximize efficiency of labor and receive good conception rates. We have a study coming out in the Journal of Dairy Science in the September issue that summarizes some of the research that we have done over the last two years where we have seen a really good result.

Is this similar to other procedures?

It is similar to what we used to have in Synchro-Mate-B which was an ear implant, except that this device is actually inserted into the reproductive tract. At the time of insertion, it is a very easy procedure. There is an applicator that is inserted into the reproductive tract, and it stays in the reproductive tract for seven to nine days. What it does is reset the cycle. One week to nine days after removal we give an injection of prostaglandin. The common commercial products are Lutalyse® and Estrumate®. If a cow has a CL, it represses that CL, so when we remove the CIDR, all those animals should be at the same stage of the cycle, and they will start coming in heat about 46 to 54 hours later.

This seems to work?

It works very well. In a timed-A.I. program what we have done is come in and at different time periods -- either 48, 56 or 72 hours after the CIDR removal -- give another injection of Gonadotropin Releasing Hormone (GnRH), which causes the initiation of ovulation. Then we do our artificial insemination. Overall, we have received conception rates right at two-thirds, or 66 percent, of the heifers.

You mentioned a study coming out. If a producer was interested in finding out more info about CIDR, or wanted to implement this on his farm, what steps should he take?

The Select Sires website and the Pfizer website both have additional information on the use of the CIDR. Pfizer is the maker and distributor of CIDR. Our particular study will be out in the Journal of Dairy Science in September, and they can then check the ADSA website and get the synopsis of this study.

That is Ray Nebel, extension dairy specialist and professor of reproductive management at Virginia Tech.

®CIDR is a registered trademark of Pfizer
®Lutalyse is a registered trademark of Pharmacie Animal Health
®Estrumate is a registered trademark of Schering Plough Animal Health

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