Scours is a Modern Disease

By Arden Wohlers DVM
Extension Veterinarian
University of Nebraska Panhandle Research and Education Center

I often listened to my dad talk about ranching when he was a kid in the 1920’s and 30’s. They were farmer/ranchers with about 50 cows and raised all of their own winter feed. There was timber on the ranch near the corrals and they had a large barn so most all of the cattle had reasonable shelter during inclement weather. Calving occurred April through August with weaning occurring near the end of the year. Scours (intestinal disease—diarrhea) was nearly unknown.

Move forward about 40 years and this situation had become vastly different. Calving season moved to February and March as ranchers needed to have older and bigger calves for weaning in October so they could move them to feedlots for a more efficient finishing phase of beef production. The cows and their newborn calves had to be concentrated near the barn so they could be protected from the winter weather and assisted if needed. Instead of 50 cows, the herd had expanded to 350 and many of the neighbors had expanded their herds too. 10 to 20% of the calves developed scours and needed treatment.

Fortunately, modern science kicked into gear and vaccines were developed for the more common viruses and bacteria that were the culprits of this epidemic. New antibiotics were discovered that could fight off many of the infections. Dehydration from the scours was the ultimate cause of death, so veterinarians and then many producers learned IV fluid techniques and proper oral fluid replacement strategies that saved many of these calves. Unfortunately the result remains in 2006 that scours in many herds still runs rampant and far too many calves die or are damaged for the remainder of their life because of a scours episode when they were young. The economics of today’s market place dictates that if a family’s only income is from a cow/calf enterprise, the herd size will continue to get larger and trend toward more concentration. What can today’s producer do to return to the disease control that was present 75 years ago and still compete in today’s market with labor practices that are cost efficient?

The first step in preventing scours in the newborn calf is to not allow exposure to the disease agent. Don’t buy off-ranch calves to graft on to cows that have lost a calf. Don’t bring any new cattle onto the ranch during the critical calving period. Don’t allow other ranchers that are also calving to come into your calving area (this is biosecurity). Don’t allow newborn calves to mix with calves that are more than 10 days older (move pregnant cows to clean pastures each week, leaving calves where they were born). Talk to your veterinarian about the sandhills calving system. Calve the heifers earlier than the main herd before there is a build up of disease agents in the calving area. A calf from a heifer needs extra precautions since the antibody protection that he gets from the first milk (colostrum) is not as good as that given to a calf from an older cow. Take care of the well calves first. Disinfect equipment and change contaminated clothing after handling sick calves. It is impossible to avoid all disease exposure as some agents are found in nature and carried from year to year by the cow herd or wildlife.

The second step is to provide the calf with the ability to fight off infection: The pregnant cow needs about 2 pounds of protein daily from a 10% protein ration to meet the requirements to produce antibodies that get delivered to the calf in the first milk (colostrum) that helps him fight disease. Protein is critical in the cow’s diet since it has all the amino acids that are the building blocks of the enzymes, antibodies, and other functional proteins that make it possible for the calf’s immune system to work. The trace minerals copper, selenium and iodine are important in the cow’s diet to have the calf born strong with a proper functioning immune system. The cow should be vaccinated for the more common intestinal infections that her offspring might develop so the calf will be protected by the antibodies passed in the colostrum. These include Coronavirus, Rotavirus, Clostridial Perfringens, E. coli and Viral Diarrhea. Some agents that cause scours such as Cryptosporidia have no effective vaccine on the market. For these agents we must resort to methods of a bygone era that is don’t concentrate baby calves, keep calving areas clean and don’t mix groups of various age calves together until they are two months of age.

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