Early pregnancy detection with your herd is a tool that producers can use to increase profits. It is essential for a producer to know early if their replacement heifers or even cows are bred. Knowing this bit of information can save you a lot of money from wasting supplements for cows that are not producing.
While it may not seem like it, the cold nights of calving season will be here before you know it. Now is the time to start preparing for the arrival of the 2023 calf crop. September is a good month for pregnancy testing your cow herd. Finding out which cows are pregnant and which are not will keep you from feeding a cow all winter, only to find out she will not provide a calf.
When it comes to pregnancy detection tests, there are two categories: Direct and Indirect. Feeling or even seeing the pregnancy are considered direct methods. Using chemical markers such as blood tests fits the indirect category. As with anything, you should look at all the options and choose the one that best fits your needs.
Types of pregnancy tests
Rectal palpation is the cheapest and the most convenient method of pregnancy testing. Using this method, a veterinarian can identify pregnant cows within six weeks of conception. What they do is feel for the calf’s head, a pulse in the artery supplying blood to the uterus, and the shape of the uterus.
Portable ultrasonic detectors are an alternative to manually doing it. It can detect pregnancy 6-8 weeks after the calf is conceived. The scanner has an external probe containing both transmitting and receiving elements. What they do is project a beam of low-energy sound waves to see if there is a fetus or not.
Simply observing any signs of estrus after either artificial insemination or natural is a simple and easy option. If the cow does not return to estrus in 18 to 20 days after breeding, then conception probably occurs. With this step, it is vital to obtain proper training for recognizing estrus behavior. There are things out there, like heat patches, paints, and chalk, that can give visual signs of mounting.
Indirect Testing
Blood tests are another way that you can go. Pregnancy-associated glycoproteins have been proven to be a reliable marker for pregnancy; currently, the tests for glycoprotein testing are highly accurate, providing 98-99% actual positive readings. From a simple blood or milk sample taken 28-30 days, producers can know the pregnancy status in 2 to 4 days. Many tests are available, including BioPYRN, IDEXX Bovine pregnancy test, and a DG29 pregnancy test, to name a few. If you are interested in this option, talk with your local veterinarian to see which to go with.
Whichever option you go with, there will be pros and cons that go with it. Do your own research and go with the one that best works for you. Looking at what facilities you have is one thing that you should look at. Also, with the fewer and fewer number of large animal vets and ultrasound technicians, it may be hard to use the ultrasound option in your area. The Texas AgriLife Extension service has a very informative article about the various types of testing.
Advantages of early detection
The main benefit of early diagnosis will be the identification of open heifers. A producer can move open animals from the more valuable feed sources. Also, they can be culled and sold in a historically higher cull market here in September. These non-pregnant heifers can continue to put on weight and then can enter the yearling market. If you are inclined, rebreeding them for a fall or late summer calving group is also an option.
In some cases, a producer can estimate the age of the calf and likely calving date during palpation. Cows that are expected to calve early can be separated from cows expected to calve late. Knowing which ones will calve early and which ones will be late can be a valuable tool in culling decisions. Remove the late calving ones from the herd to reduce the calving spread quickly. In addition, you can get more money if you know when the cows will calve if you plan to sell the bred cattle.
It is possible to identify a variety of abnormalities that cause cows to be infertile. Pregnancy tests can identify diseases and management problems that affect the whole herd much earlier. The most common issues you will likely encounter are cystic ovaries and uterine infection. It is also possible to detect the occasional freemartin when palpating.
Disadvantages of early detection
One disadvantage is the cost and the need for experience in order to get an accurate diagnosis. Palpation and ultrasound have a long learning curve for inexperienced technicians. It would be best if you also kept in mind that stress to heifers and cows early in pregnancy can cause embryonic loss.
The blood test includes a moderate cost to ship and test samples, not to mention a 5-7 day turnaround for results. This method will not allow for sorting, separation, or replacement assessment on the spot. Finding out the stage of pregnancy will not be an option if you are considering this option.
As I mentioned earlier, visually observing estrus can be a little tricky, even for experienced ranchers. Despite the experience, there are other things that can prevent estrus from returning. Things like undernutrition and lactation are both common causes of cows failing to cycle in and out of estrus. A producer may see only a few cows returning to estrus and think that more cows are in heat than there are. If you are interested in learning more about the importance of nutrition during this time, then check out my previous post, “3 tips to avoid failure in breeding season nutrition”.
What to do after pregnancy testing
If you don’t put the information you learn from pregnancy testing to good use, it won’t be helpful as a management tool. Consider the feed available, the current price, and the management system before making a decision.
It is best to cull non-pregnant cows as soon as possible. The cost of owning and keeping a beef cow for a year is very high, especially with today’s prices. For that reason, every cow on the property is fully productive. It is essential for you to look at this from a very pragmatic point of view. It doesn’t make sense to let personal feelings get in the way of any decisions.
