Pregnancy Check Cows... This Year if Ever

Livestock Update, November 1999

Dee Whittier, D.V.M., M.S., Extension Veterinarian,
Department of Large Animal Clinical Sciences,
Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech

Pregnancy diagnosis allows a cattle producer to make better management decisions about the beef cow herd. With a higher chance of cows being open this year and wintering feed supplies at an all time low, extra efforts to check all cows this year should be made.

A veterinarian using a relatively simple procedure performs pregnancy diagnosis. The arm is inserted into the cows' rectum and the reproductive tract, which lies just below the rectum, is examined. Depending on the stage of the pregnancy different structures can be felt that are "supportive" or "positive" signs of pregnancy. For example, an enlarged uterus would suggest but not be a sure sign of pregnancy. (Recent pregnancy, pus, or a decomposing fetus, as well as a normal pregnancy, will enlarge the uterus.) Feeling a live fetus or the placental membranes are examples of positive signs of pregnancy.

In some cases the veterinarian may be able to estimate calving dates based on pregnancy checking. Checking cows at earlier stages of pregnancy allows a veterinarian to more accurately predict the calving date.

Having cows pregnancy checked requires an adequate facility. Cows must be put into a head catch so that they are well restrained for the procedure. There must be a way for the veterinarian to safely get behind the cow to perform the examination.

Costs for having cows checked for pregnancy will vary but are in the range of a few dollars per cow. Many veterinarians who provide pregnancy diagnosis perform the service on a fee-for-time basis. Thus if a facility functions well enough to allow checking 30 cows per hour the cost per cow is much less than if only 15 cows can be examined per hour.

Ultrasound technology is now available for cattle pregnancy diagnosis by some veterinarians. Use of the ultrasound is made when early diagnosis (down to 26 days versus 35-40 days for manual examination). Ultrasound will also allow sexing the fetus if examined between 50 and 70 days after breeding. These advantages will not justify this more expensive procedure in all cases.

To have cows pregnancy checked and then to make no change in management may satisfy curiosity but results in no economic return to producers. The most common things that knowing the pregnancy status of a cow allows a producer to do include:

1. Culling open cows from the herd.
2. Making decisions about breeding bull well in advance of the next breeding season
3. Managing cows at different stages of pregnancy in different ways. For example, cows that are going to calve later in the season may be culled, sold to another producer, or managed differently in terms of nutrition.

This year pregnancy diagnosis is especially important because a higher percentage of cattle are expected to be open. This is a function of weather conditions in Virginia during the last year. Lack of rainfall during the last year has resulted in cows that had lower body condition at calving last spring. Poorer quality hay last winter accelerated this weight loss. A dry spring did not allow cows the weight gains in the early season that normally occur. Finally, very hot conditions this summer may have decreased conception rates.

If you are one of Virginia's many producers who has less feed stored for the winter, identify open cows and sell them or manage them so that they do not take scarce resources from cows that will deliver calves in the spring.

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