Annual data from the National Animal Health Monitoring System confirm that scours continues to be a leading cause of calf mortality and a major source of economic loss for beef producers. Most cow/calf producers are all too familiar with the prevalence of scours and the financial impact it can have on their operation.
But what producers might not realize is that calves born to first-calf heifers are significantly more vulnerable to scours than calves born to older cows. In fact, research has shown that the odds of a calf dying from scours are six times greater when it’s born to a first-calf heifer, as compared to an adult cow.
Dr. H. Nielsen, professional services veterinarian for Novartis Animal Health, says that’s just one more reason heifers require special attention to ensure the health and productivity of both the heifer and the calf.
“Adult cows vaccinated properly on an annual basis have stimulated antibody production to a higher level due to repeated antigen exposure from numerous vaccinations, helping protect against the bacterial and viral pathogens that cause scours,” said Nielsen. “Consequently, higher antibody levels in the cow mean higher antibody levels in the colostrum to pass on to the calf.”
“Heifers, on the other hand, haven’t yet been exposed to antigen loads high enough to stimulate their immune systems. So typically, the level of protective antibodies in a heifer’s colostrum isn’t nearly as high as it is in the adult cow’s.”
To help boost those antibodies in heifers, Nielsen advises producers to focus first on nutrition. “Nutrition is really the foundation for heifer health, including their ability to provide high levels of maternal antibodies to calves through colostrum,” he said.“With proper nutrition, heifers will respond much better to all vaccinations—including scours vaccines—and produce more circulating antibodies,” adds Nielsen.
Heifer rations need to include sufficient energy, protein and vitamins A and E, as well as the most significant trace mineral elements: selenium and copper.And producers should work to ensure heifers are on an increasing plane of nutrition when in development pens.
Equally important is immunization of the heifer with an effective, broad-spectrum vaccine like Scour Bos®. Heifers should be vaccinated 8 to 16 weeks before calving, followed by a booster dose four weeks prior to calving with Scour Bos 4.
According to Nielsen, one of the biggest advantages of using Scour Bos is that producers can vaccinate heifers for scours sooner than they can with other vaccines, including at preg-check, enabling the heifer to produce higher levels of antibodies.
“The goal is get antibody levels as high as they can be four to six weeks before calving,” said Nielsen. “That’s when antibody begins to transfer into colostrum.”
Preventing scours in calves born to heifers is an important herd health strategy that can help drive maximum profitability.Shoring up heifer nutrition and vaccination programs will go a long way towards reducing the overall prevalence and impact of scours on cow/calf operations.