Select Sires

Sire Fertility, Part 1
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired Sept. 16, 2004
With Jeff Stephenson,
Professor of Animal Sciences,
Kansas State University

This week's Reproductive Moment is with Jeff Stephenson, Professor of Animal Sciences at Kansas State University. Jeff, this week we are talking about sire fertility estimates. Let’s start with ERCR.

The original sire estimate program was called ERCR; that is what was called estimated relative conception rate. It is a source for sire fertility that has been made available by one of the dairy record-processing centers in Raleigh, N.C. It is based on a large number of inseminations of sires used through the information that is made available to that record-processing center, and there are about 1.6 million cows processed through that center each year. All of the information that is available -- which mostly reflects east coast, southeast and some mid-west states -- is processed through that center and provides information about sires of cows and heifers that have been inseminated artificially.

What is it based on?

The ERCR is based on a non-return rate, which means if the cow is not once inseminated, the sire code is identified that the cow has not been re-inseminated after a period of time (usually 90 days), and they assume that the cow is pregnant to the last sire reported. Of course, there are many reasons that a cow may not be re-inseminated, which would make that non-return rate somewhat inaccurate. In other words, a cow may have been re-inseminated to another sire from another bull-stud that wasn’t reported, she may have been sold, she may have died, or the dairy farmer decided he didn’t want to re-breed that cow anymore so she is open and he is going to milk her out until he sells her. So, the estimates are not absolute estimates of exact sire fertility, but on a relative basis, when you compare one sire to another, which is done much like sires are compared for our PTA or milk, or any other trait which we have a predicted transmitting ability, the relative differences among sires is quite accurate. That is what has been available for a number of years, until this recent new sire fertility estimate has come out.

Explain the new one.

The new one is being offered by one of the dairy records-processing systems in California known as AgriTech Analytics and it is one that is based in Visalia, California. They service primarily western herds, although they have cows here in Kansas. We have cows in a number of states besides the western states that use that dairy record-processing center. What is unique about the sire fertility estimates that are made there, which are being put together in cooperation with Dr. Kent Wigel at the University of Wisconsin, is that these sire fertility estimates are based on actual pregnancy outcomes. In other words, they are based on veterinary palpation checks, so that information has been provided to the dairy records processing center for every sire, then there is a large amount of record examination and gleaning of the records to make sure that they are accurate to discard information that may not be accurately reported, and so-forth, to arrive at these sire estimates.

Thanks Jeff. We will talk more next week. That is Jeff Stephenson, professor of Animal Sciences at Kansas State University.

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