How to confirm heifer heats

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Necessity is the mother of invention.

And necessity is exactly what led veterinarian Don Gardner to develop a protocol to get heifers bred without having to watch for heats several times during the day. His custom-heifer raising operation in Huddleston, Va., was growing, and his dairy practice kept him busy and away from the heifer ranch most days.

Being the only full-time A.I. breeder for the operation, "I had to develop a way to make heat detection and breeding as time-efficient as possible," says Gardner. "So, I developed a program that shows me what goes on even when I'm not here."

Using the protocol, he routinely gets 90 percent of heifers pregnant in two services or less. He averages 71 pregnancies for every 100 straws of semen used. And nearly all heifers are bred by 15 months of age.

While he has more help now — his youngest son returned from college to help manage the heifer ranch — they still use the same protocol to get heifers bred. After all, it's not expensive, it's time-efficient and has a proven track record.

Use the following steps to learn how to confirm heifer heats before breeding. Doing so will allow you to get heifers bred without having to watch for heats throughout the day.

1. Use Kamars and chalk.

When you don't observe for heats, you need to use more than one indicator to help judge if the heifer is truly in heat, explains Gardner. Using only one indicator may mislead you; using two rarely does. Place a Kamar heat-mount detector on each heifer's tailhead and then apply chalk directly behind it on the curve of the tail.


2. Check heifers every day.

At Gardner"s heifer ranch, all heifers receive a TMR once daily. Simply walking down the line of heifers while they are locked up and eating will reveal any Kamars that may have turned red. (You can't skip a day or two and make this system work. It requires heifer checks seven days a week.)


3. Evaluate the markings.

If the Kamar is red, but the chalk is not really disturbed, the heifer may not be in heat. But if the Kamar is red, all of the chalk is rubbed off, and the normally white material on the Kamar patch is dirty, then she definitely is in heat. Go ahead and breed her.

For the heifer that is in question, you have to do more investigation and add up the clues. Cut open the Kamar to reveal how much dye has left the tube. If the tube is still half full, and the chalk has not been rubbed off, she could just be coming into heat or may not be in heat at all. If you determine that a heifer is not in heat, replace the Kamar and chalk markings that day. 


4. Examine the vulva.

Next, look closely at the vulva. If the heifer is in heat, the lips of the vulva will swell slightly and the interior lining turns a somewhat darker pinkish color. (In the photos shown at left, the heifer on the left shows no signs of being in heat. In the one on the right, the lining of the vulva is slightly darker than normal, but swelling is not yet present.) You'll also want to look for the presence of any clear mucous. The swelling of the vulva is the most important of these clues.


5. Do an internal exam.

During the rectal exam, you will check for uterine tone. The uterus should feel toned and erect. In addition, if you place your hand on her cervix and gently use your fingers to rake it back toward you, it should expel some mucous from the vulva. If no mucous expels, it could be that she has been in heat a long time. In that case, when you rake back from the cervix, you may hear a squishy sound (like water being squished out of a really wet washcloth).  Or, if she is early in heat, you may get globular mucous instead of stringy mucous. Either way, she can be bred. The presence of stringy, elastic clear mucous is strong evidence of heat.

And be sure to create a record of all breedings.


6. Prepare for a second time around.

When working with heifers that need a second breeding, you also will want to check if the date coincides with her last breeding. If she has a red Kamar, and it's just 10 days after her first breeding, you can pretty much rule out that she's in heat. Make sure the timing of the second heat coincides with the last breeding.


Heifers are curious and somewhat playful by nature. Because of that, you should expect that about 15 percent to 25 percent of all red Kamars will be false-
positives during a 45-day breeding period for a group of heifers. During the repeat breeding period, there will be even more false heats to sort out than in the first go-round.

But when you add up all of the clues, it becomes easy to judge if a heifer is truly in heat and should be bred or if it's a false-positive. Remember, practice makes perfect.

His overall breeding plan

In order to get heifers bred quickly and move groups through his breeding pen, Don Gardner, veterinarian and custom-heifer grower in Huddleston, Va., uses the following protocol.

1.         Put breeding-age heifers into a pen with headlocks. (His breeding pen has room for 59 heifers.) Let the heifers acclimate to the pen for three or four days.

2.         Lock up the heifers and apply a Kamar heat-mount detector and chalk markings to each one.

3.         Feed once daily and look for signs of heat during the next four to five days. Breed any animals that you find in heat.

4.          Give all heifers that have not come into heat a shot of prostaglandin. This will regress the corpus luteum and bring the heifers into heat. Generally, two to four days after the shot, about 75 percent to 80 percent of the rest of the heifers will come into heat. 

5.         Continue daily checks to watch for signs of heat. Breed any animals that you find in heat. Usually, the next three or four days is pretty quiet.

6.         One week after the first shot of prostaglandin the heifers that still have not come into heat should get another shot of prostaglandin. (Generally, about 10 percent to 20 percent of heifers do not to respond to the first shot.)

7.         Continue daily checks to watch for signs of heat. Breed any that you find in heat.

8.         If any heifers still do not come into heat, have your veterinarian do a rectal exam. If the heifer is not a freemartin, has no ovarian activity, but has a normal reproductive tract, use a CIDR. Install the CIDR for one week. When you remove the CIDR, give her a shot of prostaglandin and she should come into heat within two to three days.

9.         When heifers are one week away from coming into heat again, put Kamars on and chalk their tails. Start checking for heats daily. Use the steps listed above to determine whether or not repeats are truly in heat or not.