Probiotics: Live Organisms as Feed Supplements to Fight Salmonella
19-Feb-2008 12:00 AM EST
Newswise — Here's a new way to reduce Salmonella in poultry before they go to the processing plant: use probiotics instead of antibiotics for treatment of the birds.
It's been a complex path getting to this point, and the procedure still raises some other issues to be considered. Still, the development offers a way that makes it easy on poultry growers and enhances food safety.
It's a matter of incorporating the probiotic into either the water or the feed for the poultry, explained Billy Hargis, director of the Poultry Health Research Laboratory at the University of Arkansas System's Division of Agriculture. Results from experiments show that administration of the probiotic can reduce Salmonella in either meat-type chicken houses or turkey houses before being transported to the processing plant and reduce the risk of cross contamination among turkeys at the plant.
"It's not a chemical. It's not a drug," explained Hargis, who has pursued the research for the Food Safety Consortium. "These (probiotics) are live organisms." The term for the probiotic developed in Hargis' lab is FM-B11, also known as a defined lactic acid bacterial culture. Defined cultures eliminate the risk of pathogenic organisms existing within the culture, clearing the way for their effective use in stopping Salmonella in commercial poultry.
"Another advantage is that we're talking about organisms that can be producedvery cheaply, which keeps the costs of these treatments very low," Hargis said. That's partly because the defined cultures from which the probiotics come are tolerant of oxygen, avoiding the high cost of fermenting undefined cultures that can't grow in the presence of oxygen.
Antibiotics have long been popular among poultry producers seeking to keep their birds healthy and to promote the birds' growth. Pathogenic bacteria that are harmful to humans are increasing the bacteria's ability to resist antibiotics, but pathogens that can cause animal disease have not built up as much resistance.
"The risk factor for antibiotic resistance from food-producing animals is exceedingly low," Hargis said. But the issue of antibiotic resistance is still becoming a driving force that's making antibiotics usage for animals less popular, and poultry producers are under pressure to use fewer antibiotics. Alternatives are necessary.
Probiotics enter the picture as live organisms that serve as microbial feed supplements for animals to improve their intestinal microbial balance. Hargis' research group has taken the lactobacillus probiotic, a form of milk bacteria found in the bird, and added it to poultry water or feed.
More recent efforts are directed toward beneficial bacteria from a totally different genus called Bacillus. During the last year, a substantial laboratory effort has been directed toward identification of organisms of this genus that are harmless to the animals or humans, which inhibit certain pathogenic organisms, and which can produce spores that are resistant to heating or storage. The important part of these new efforts is to develop effective probiotics that can be added to feed, which greatly reduces costs associated with delivery in the drinking water at the farm.
"We can add these to the feed even before pelleting," Hargis said. "The beneficial bacteria in the feed have tremendous advantages because now we can talk about continuous administration over time. It makes it very simple. It just comes in with the feed."
Replacing antibiotics with probiotics has definite advantages, but there is some tradeoff. Hargis noted that although animal foods won't be populated with antibiotic-resistant bacteria, the lack of antibiotics means producers will need to find other ways to promote their birds' growth. That means giving more feed to the birds to accomplish the task.
"It's going to take more feed to raise the same amount of meat," Hargis said. "So that means more land has to be involved in row crop production. There's an effect on the world's small grain supply because we'll be putting more small grains into the same amount of meat than we were before." Meanwhile, the price of grain is already going up to meet demand for biofuels, so the price of meats produced from small grains will also rise.
But the advantages offered by probiotics indicate where the future may be. Hargis cited the new probiotic candidate's stability even in the presence of the heat generated when feed is being turned into pellets and its overall environmental stability. The major plus is its usage in the feed itself, which makes it part of an ongoing process.
"We're using it to prevent problems continuously as opposed to treating problems when they occur," Hargis said.