Gut Health First
With VFD closing in, alternatives to low-level in-feed antibiotics are necessary.
The veterinary feed directive (VFD) will become effective in December 2016. At that point, any cattle producers who plan to add antibiotics to feed or water will need to have a veterinarian’s authorization to do so, and these antibiotics can only be used for the purpose of disease treatment or prevention rather than for growth promotion.
It actually makes more sense to treat disease therapeutically (at levels high enough to kill or halt pathogens) than with low levels in feed, says Chris Chase, professor in the Department of Veterinary and Biomedical Sciences at South Dakota State University (SDSU). “This is because we are beginning to understand how important the resident bacteria — the microbiome — are in the GI (gastrointestinal) tract.” If we hinder resident bacteria with antibiotics, we adversely alter gut function.
“We learned about this after people got infections with Clostridia difficile,” he notes. “Generally, the only reason we see this disease in humans is because they’ve had a massive antibiotic treatment and their microflora didn’t bounce back the way it should.”
The resident bacteria in the gut (of a human or animal) provide protection against pathogenic bacteria in the GI tract. Healthy, thriving populations of “good bacteria” don’t give pathogens a chance to move in.
“One of the ways to resolve this problem when people have lost their microbiome has been to give the sick people fecal transplants, to re-establish the good bacteria — from other people’s microbiome,” Chase explains. “Then, they recover dramatically and don’t need antibiotics anymore. I think in the future we just need to use antibiotics more prudently. In food animals, continual low-level antibiotics in their feed or water can mess up their microbiome.” Basically, keeping the gut healthy is much more important than using antibiotics in feed.
“Some people complain about having a bad gut, and I think there’s a lot to that. We’ve discovered how important the intestinal tract is as an immune organ," he notes.
Chase says a healthy gut is paramount when it comes to keeping a calf or human healthy.
“If the cells in the intestinal lining do what they are supposed to do, the chances of getting a disease caused by salmonella or some other intestinal pathogen are very low,” he says. “Healthy cells in a healthy intestinal lining keep pathogens from coming through.”
Problems occur when the immune system is overreacting, Chase says. “This is what we see with Johne’s or Crohn’s disease, where the inflammation is coming from the immune system. It has turned against itself, overdoing things.”
The constant inflammation causes the intestinal tract to be unable to absorb nutrients and fluid, and the animal or person experiences diarrhea, he explains. It is important to keep gut health in mind. This sometimes means using probiotics (supplements that include some of the normal flora in the gut) and prebiotics (things that “feed” the probiotics).
“Probiotics and prebiotics have been around for a long time, but we are beginning to understand them better,” Chase notes. “As we look at the microbiome, I think part of the reason that some years these things work to help sick calves and some years they don’t is due to the health situation in those calves. Giving probiotics and prebiotics to calves won’t hurt anything, but some years the effect they have is just more dramatic.”
One more thing producers deal with is feed changes, he points out, such as switching from a milk diet to a concentrate diet, or changing the diet in the feedyard.
“We tend to see increases in illness at those times, shortly after the change in diet, and it may be due to a ‘bad gut,’ ” he says. “As we begin to understand these things better, we may be able to manage some of these problems with direct-fed probiotics and prebiotics that will help — and this will enable us to use less antibiotics.”
Editor’s Note: Heather Smith Thomas is a freelancer and cattlewoman from Salmon, Idaho.