Many commercial or purebred producers and auction markets are realizing the benefits of palpating heifers pre-breeding. This can also be done at pregnancy checking and involve a more thorough exam than simply a determination of whether they are pregnant or not. I will try and highlight some of these and explain how this may economically benefit your operation.
With the advent of very early maturing breeds such as Gelbvieh, Angus, Simmental and others, it is not unusual for unwanted pregnancies to occur when breeding bulls are left out late. By palpating early these pregnant heifers can be identified and removed from the breeding group. If they are not heavily pregnant (less than four months), abortion is a possibility as long as there is ample time for rebreeding.
My advice for heavily pregnant animals (seven months or greater) is to calve them out. A fair percentage will calve normally. Palpating will at least identify them and give you an opportunity to segregate them. If you do abort them keep in mind they need time to clean up for rebreeding and a percentage will not rebreed so it is a risk you take.
Aborted heifers generally retain their placenta so rebreeding takes longer than with a normal calving. If aborted under three months gestation I find they will clean up rather quickly (within a month) and be ready for rebreeding.
If pregnant ones are found a dialogue should ensue. Consult your veterinarian regarding stage of pregnancy and whether they should be aborted, left to calve or marketed. If you decide to abort be sure and identify them in case they have problems or you want to repalpate them to be doubly sure that the abortion worked.
When palpating open heifers we are looking for several things. An intact uterus is necessary to conceive and evidence of cycling can be detected by palpating both ovaries. You can detect twins. With large herds the records of twin calves can often be lost with the grafting of twins to cows which have lost calves for various reasons. Freemartins (heifer calf born twin to a bull) can be detected by palpation and eliminated, as often they have only a very rudimentary uterus, or none at all. Conversely, in about five per cent of cases an intact uterus with two ovaries are present and these can be retained and most times will breed.
Keep in mind palpation is almost synonymous with ultrasounding and veterinarians will use whichever technique they are most comfortable with. Either technique in the right hands provides accurate results and increases conception rates.
Various strategies for grading the development of the reproductive tract have been tried. These are based on the size of the reproductive tract and degree of development of the ovaries. Veterinarians basically want an adequately developed uterus with ovaries that show some sign that cycling is occurring. This is more critical the closer to breeding season when we palpate.
Keep in mind certain breeds develop earlier than others.
If you have lots of grass, freemartins will exhibit growth approaching that of bulls. They commonly still cycle from rudimentary ovarian tissue so will keep the bull busy all summer.
Pelvimetry can also be performed at the same time. Both the Rice and Krautman pelvimeters are accurate in experienced hands. We use them to measure the minimum height and maximum width of the pelvis. I am most familiar with the Krautman tool which calculates pelvic size in square centimetres and predicts the birthweight in pounds that a heifer could deliver with little or no assistance.
All these techniques are used to avoid potential C-sections or hard pulls next spring by eliminating small pelvises. We can select for larger pelvises while maintaining moderate body size.
Palpating also uncovers misshapen pelvises, adhesions (scar tissue), kidney infections, cystic ovaries or other internal cysts and masses. The decision then becomes to market these animals or keep them as replacements.
Weight is good way to compare heifers so if possible get a weight. If any genetic tests are desirable, especially with purebreds, your veterinarian will grab a hair or blood sample as well. It is often desirable to avoid selecting the most rapidly growing heifers for replacements. Avoid the top five per cent. They are often hormonally more like males and as a result conception rates are lower.
By tying in all these procedures with palpating you will be going a long ways toward selecting sound heifers that hopefully will be very productive and provide fertility and longevity to your herd.
If palpating was missed last spring you can incorporate pelvimetry into pregnancy checking in the fall to look for potential calving problems. If it’s done early enough to predict those that conceived in the first, second or third cycle, the pregnancies can be staged. We need heifers calving right at the beginning of the calving season or even a cycle earlier so they rebreed and remain in the herd their second year.
Be sure to vaccinate the bred heifers for scours, especially if you are bringing them into your herd.
Palpating while reading the ear tags makes it easier to get some of this useful selection information into your database along with the usual notations for feet and legs, body condition and temperament.
In the future with more genomic testing, we will no doubt be adding to this list by selecting for disease resistance, parasite resistance and even fly resistance.