Select Sires

Heat Expectancy List
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio Which Aired March 31, 2005
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. Ray, this week we are talking the about top dairy records for better management. Let’s start with the heat expectancy list. That is pretty important, isn’t it?

That's righ, Bill. Day to day there are not a lot records that you really need for reproduction. We cannot check pregnancies after a certain period of time, usually no earlier than 33 days, but day-to-day we need to know what cows are ready for insemination. The cow that we bred three weeks ago, if she is on a normal estrus cycle, will be coming back in heat. We call that a heat expectancy list. If they don’t come back, hopefully they are pregnant. But, if we have a 50 percent conception rate, it would say that half the cows that we breed should conceive and become pregnant, and then won’t come back in heat. But, half the cows from that list won’t conceive, and we should expect them back in heat at a normal estrus interval within 18 to 24 days. Therefore, this list is a very critical list in day-to-day management.

You called that a "heat expectancy list"?

That's right. Heat expectancy list, because we don’t take anything for granted. We expect all those cows to come back in heat. If we go into a pen of cows, say 100 cows, we might have 20 cows where we would say the odds are that half of them will be in heat sometime this week, so a heat expectancy list gives us a better likelihood of catching that cow if we can anticipate her heat, look for the subtle signs. This heat expectancy list is which cows we expect to come back in heat, based on their earlier breeding.

When we look at these lists, we will also look at a vet check list.

The vet check list is probably the second-most-used list. The vet check list would be the list of cows that you did not catch in heat. When the vet comes to do his pregnancy check -- once a week or every other week or once a month -- you are having him palpate these cows to see which cows are actually pregnant and which ones you might have missed in heat. So, if we examine 20 cows in this pen today and 10 of them are pregnant, that would give us a 50 percent pregnancy rate. But, what that says is that 50 percent of the cows we missed in heat. So a lot of dairy producers look at that as a conception evaluation, but it is really a heat-detection evaluation.

What are ways to improve on that missed-heat percentage?

Again, using the heat expectancy list would be one to help us anticipate those cows in heat. Using secondary heat-detection signs or aids such as chalk or tail paint, or heat patches such as KAMAR® or BOVINE BEACON®, can help with cows that show very subtle signs of heat and not very obvious signs of standing. And all of these heat-detection aids are supplied thorough Select Sires distributors. So, in cows that just have a few mounts, these little aids or tips, the paint that is put across the tail heads, the KAMAR, or the BOVINE BEACON would allow us to catch some of these cows that we normally wouldn’t catch if we weren’t using some of these little tricks or aids for heat-detections.

Thanks, Ray. That is Ray Nebel, Extension Specialist and Professor of Reproductive Management at Virginia Tech.

®KAMAR is a registered trademark of Kamar Inc., Steamboat Springs, Colo.
®Bovine Beacon is a registered trademark of Omniglow Corp., W. Springfield, MA.

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