Pathogen Control
- Pathogens such as E. coli O157:H7 can be present in the rumen contents of healthy cattle.
- In some cases these pathogens can survive the acidic conditions of the abomasum (i.e. the gastric stomach) and colonize the lower gastro-intestinal tract.
- Some nutritional factors, such as the lower rumen pH of grain-fed animals, can lead to pathogenic bacteria becoming acid tolerant and therefore increase their ability survive acidic conditions such as those found in the abomasum.
- It is not clear if this increased acid tolerance has any practical significance as several studies have shown no effect of grain in the diet on increased shedding of pathogens by cattle.
- However, bacterial direct-fed microbials have been shown to be effective in controlling growth of both acid sensitive and acid tolerant pathogens in rumen fluid, and they have other effects in the intestinal tract that increase their effectiveness as pathogen control interventions.
- These interventions are effective in both improving the intestinal health of the animal and addressing the ever increasing food safety concerns.
Microcell LA and E. Coli
Microcell LA and Salmonella
Research conducted by a team from the College of Agriculture at North Dakota State University investigated the effect of Direct Fed Microbial (DFM) products on the control of E. coli in feedlot cattle. The health benefits of intestinal pathogen inhibition in livestock through direct-fed microbial feeding are seen not only in increased efficiency in the animal, but serve as a pre-harvest food safety intervention. The University of North Dakota study showed that feeding L. acidophilus resulted in:
- A 32% reduction fecal shedding of E. coli O157:H7 among the steers treated with the Lactobacillus Acidophilus BT1386.
- Steers being almost three times less likely to shed E. coli in their feces when compared to steers fed no direct-fed microbial.
- A significant reduction in the probability of new infections with Salmonella.
- This pathogen inhibition occurs by attachment of L. acidophilus BT1386 bacteria to intestinal surface, thereby inhibiting the attachment and proliferation of pathogenic bacteria in the intestine, and through production of lactic acid that causes a reduction in pH in the intestine.
This work was published in the March 2008 issue (with an erratum in the May 2008 issue) of the Journal of Food Protection.
DFMs may help reduce fecal E. coli shedding (Feedstuffs - May 19, 2008)