Fetal Anomalies, Fetal Demise and Failure to Calve

Experienced pregnancy testers know that a percentage of the cows and heifers that are called pregnant, fail to calve. This fact raises the question: what happened to the pregnancies? Let’s discuss a few of the many factors involved in “failure to calve”.

1. The earlier one pregnancy tests, there is increased likelihood that a percentage of the cows with viable embryos or fetuses will fail to calve. This is well documented in dairy herds where pregnancy testing with ultrasound can start as early as day 28 of gestation. Failure for these embryos to develop to term and calve normally is usually credited to the demands put on productive dairy cattle. The percentage of embryonic or fetal loss considered acceptable ranges from 2% to 15% in dairy herds depending on factors such as ambient temperature, production level in the herd, start date of pregnancy testing, level of twins and other factors.

2. Another important consideration is disease. Infectious diseases such as Trichomoniasis, IBR, Brucellosis and non-infectious diseases such as Vitamin A deficiency should be thoroughly investigated if dead fetuses or abortions are detected or the percentage of cows that fail to calve is too high. How high is unacceptable? 1 to 2 per cent is often the “accepted failure to calve” level in well managed herds on the Northern Great Plains. It seems that a higher level of “failure to calve” is acceptable in Bos indicus cattle in warmer climates. Beef producers should discuss “failure to calve” with their veterinarian and know if their herd warrants further investigation.

3. Another cause of “failure to calve” is fetal anomalies. These are rare events that can be detected by examination of the fetus during ultrasound pregnancy testing. If an experienced person ultrasound pregnancy testing takes a few extra seconds per cow, twins, dead fetuses, and fetal anomalies may be detected. This is very valuable information that will not be available if the only criteria for pregnancy testing skill is “how fast can you go”. Click on this link to see some interesting video clips of fetal anomalies and fetal demise.

ReproScan has a strong commitment to training programs and providing technical support for user of its ultrasound equipment. Your feedback helps us improve these programs. Please send us your thoughts on this discussion on “failure to calve”. If you have any captured images that you would like to share, please forward them to inquiry@repro-scan.com. They are greatly appreciated.

Merry Christmas and Happy Pregnancy Testing,

Andrew Bronson DVM


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