When abortion and calf losses exceed the norm, producers turn to veterinary diagnostics for answers.
STAUNTON, Va. (Oct. 16, 2013) — If you keep livestock long term, you will experience death losses. Most cow-calf producers expect to suffer some losses due to abortion and stillborn calves. However, they typically expect those to occur in a very small percentage of pregnancies. When they occur in numbers exceeding expectations, producers want to know the reason or reasons, and whether action is needed to prevent further disappointments. That’s usually when they turn to the veterinary diagnostician.
“Too often the answer to the problem is left dangling between the cow’s hocks,” stated Larry Holler, enouraging cattlemen to submit the placenta, as well as the fetus or calf, when seeking answers to why a cow aborted or lost a calf.
According to South Dakota State University veterinarian and reproductive disease specialist Larry Holler, producers often provide too little evidence to diagnostic laboratories. Speaking at the Applied Reproductive Strategies in Beef Cattle (ARSBC) symposium Oct. 15-16 in Staunton, Va., Holler said good answers depend on having an accurate herd history — including information about herd nutrition, immunizations and purchases — and a good submission.
What is a good submission? Ideally, it includes the aborted fetus (or dead calf) and the placenta. However, producers more often provide only the fetus or calf. Holler said that is sometimes enough. Pieces and parts (the lung, liver, spleen, heart and other tissues with gross lesions) may even work, but Holler calls the placenta valuable evidence.
“I would argue that the placenta is more valuable than the fetus. Too often the answer to the problem is left dangling between the cow’s hocks,” stated Holler. “People say I’m obsessed with the placenta, but if I have to choose, I’ll take the placenta.”
Holler said abortions, stillborns and weak calves are often the work of various infectious agents that can be bacterial, viral or fungal. However, he is finding more problems resulting from what he calls “opportunistic pathogens.” These are organisms common to the environment that don’t normally cause problems. Numerous bacillus species of bacteria present in the soil make good examples.
Holler suspects the feedstuffs used during recent years and the ways they are processed and fed are to blame. He noted that because of high feed costs and drought, more low-quality forages are fed to cows. This includes baled corn stover and other crop residues that contain dirt. These forages, as well as hay containing spoilage are ground and blended in total mixed rations.
“Cows can’t be selective because everything, even spoilage and dirt, is ground and mixed together,” said Holler, noting that limit-feeding of cows also discourages selectivity.
Use of vertical mixer wagons has increased and bale processors have become quite common. Drought conditions have led to more mixed rations and processed hay being fed on bare soil. In some situations, Holler believes every bite includes a fair amount of soil and soil-born bacteria. In sufficient concentrations, these “dirt bugs” can cause trouble.
“The bacteria peck at the placenta, doing a little damage here and a little there. It adds up, and the total damage can be significant,” Holler explained, adding that reproductive consequences are most common in immune-compromised cows.
Holler said mycotoxins produced by fungus also may cause abortions. Producers should keep that in mind if their feedstuffs appear moldy.
“If there is ‘white’ in it, you’re probably growing a fungus of some flavor. Feed that to something that doesn’t have a uterus. It would be better yet to throw it away,” advised Holler.
Holler spoke during Wednesday’s ARSBC session focused on dealing with pregnancy and birth losses. Visit the Newsroom at www.appliedreprostrategies.com to listen to his presentation and to view his PowerPoint slides and proceedings paper. This comprehensive coverage of the symposium is compiled by the Angus Journal editorial team. The site is made possible through sponsorship by the Beef Reproductive Task Force.
Editor's Note: This article was written under contract or by staff of the Angus Journal. To request reprint permission and guidelines, contact Shauna Rose Hermel, editor, at 816-383-5270.