REPRODUCTIVE LOSSES IN BEEF CATTLE: DIAGNOSING THE CAUSE
BY TAYLOR GRUSSING SDSU Extension Cow/Calf Field Specialist
Reproductive losses account for $1 billion dollars in lost revenue to the beef industry each year. All the way from conception to birth, we depend on a lot of things to go right, whether we are talking about natural or artificial breeding programs. Nevertheless, reproductive failure whether presented as early or late term abortions (miscarriages) result in those animals never being born and having a stark effect on the operation’s bottom line. Utilizing proper health and nutrition programs are ways we can try to reduce reproductive failure from occurring. Yet, if failures occur, diagnosing the cause can be helpful in preventing the issue in the future.
POSSIBLE CAUSES It is often difficult to pinpoint exactly what went wrong when abortions occur. All livestock producers expect a certain degree of late-term abortions or stillbirths. It is generally accepted that any cattle operation will have 1-2 percent of “normal” pregnancy loss after a month or two of gestation. With spring calving herds, January and February are when many abortion cases are submitted to the SDSU veterinary diagnostic
laboratory. In about half of the cases submitted to the SDSU diagnostic lab, no abnormalities are detected. There are many reasons for this, such as that the infectious agents are often not detectable anymore by the time the fetus is expelled, or stillborn calves were aborted due to abnormal presentation or twin pregnancies. In the rest of the cases, something abnormal is found. A frequent finding is inflammation in the placenta that may or may not be traced to a specific germ. The placenta in a pregnant animal is the gateway from the mother’s blood supply (carrying nutrients and oxygen, but possibly bacteria and viruses) to the fetus. If something affects that critical tissue, then the fetus may become starved from oxygen and die. When germs are found, they are often more environmental than contagious in nature, and very few cows experience problems. Lastly, sometimes infectious agents such as IBR, BVD, or leptospirosis are identified, for which effective vaccines are available.
ABORTION DIAGNOSIS So what should a cattle producer do when a late-term abortion is encountered? Start with your local veterinarian to discuss the
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details of your issue and whether ► Number of animals in the there are similar problems in other herd, including recent purchases or neighboring herds. When the movements number of abortions in a group ► Number of abortions and exceeds one or two, it’s generally previous diagnoses, if any time to get a diagnosis. ► Age and breed of dams ► Gestational age of abortions SAMPLE SUBMISSION ► Pertinent treatment or Diagnostic success can be vaccinations improved by promptly submitting the proper samples. While the USING RESULTS following recommendations are Depending on the results, your likely sufficient for most veterinary veterinarian will follow up and advise diagnostic laboratories, your you on potential herd management veterinarian should confirm these changes. If an environmental cause with their particular lab. When such as mold is identified, examining possible, the entire fetus and feed sources is a necessary placenta — chilled but not frozen — intervention to determine what is the most desirable specimen. The feeds are contaminated. In addition, placenta is of particular importance if infectious agents are found, and should be included whenever implementing a sound pre-breeding possible. Significant microscopic vaccination program for next year’s changes and germ identification heifers is a must. Cow vaccine often stem from examining the boosters to prevent early and late placenta. Other samples to submit term abortions should also be if you do not want to send in the considered. whole fetus include, heart, lung, liver, kidney, spleen, brain, skeletal THE BOTTOM LINE With reproduction, focusing on muscle (tongue or diaphragm), fetal stomach fluid and fetal thoracic what we can control and diagnose fluid or heart blood. A veterinarian is the key to helping avoid these will likely collect and send these losses within our herd. For more samples off for you; however, the information contact your local Extension field herd history information should veterinarian, be given to them to assist with specialist, or Russ Daly, SDSU Extension Veterinarian. choosing diagnostic tests. — Source: SDSU Extension Information to include: