Features
Probiotics Help Produce Safer Chickens, Study Finds
Treating young chickens may better protect consumers against disease bacteria
BY RACHELLE COOPER
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| Prof. Shayan Sharif studies the use of probiotics against disease. Photo by Martin Schwalbe |
Giving chickens probiotics — microbial dietary supplements that contain live beneficial bacteria — stimulates their immune system and reduces Salmonella bacteria in their gut, a team of researchers has found.
“We looked at the immune-enhancing ability of the probiotic and, lo and behold, the probiotic actually seems to be quite an immune stimulator,” says Prof. Shayan Sharif, Pathobiology, who collaborated with James Chambers of Agriculture and Agri-Food Canada. Their research was recently published in Clinical and Vaccine Immunology.
This means chickens treated with probiotics early in life are able to mount higher immune responses and, as a result, may be better protected against disease-causing microbes, says Sharif.
“After looking at the antibodies in the intestine and blood of the chickens, we found that the antibodies were more than twice as high in chickens treated with probiotics.”
The researchers also looked at two kinds of Salmonella that are most prevalent in Canada and found that some probiotics reduce very substantially the level of colonization of the bacteria in the chicken gut.
Salmonella bacteria occur naturally in the chicken gut, and the gut contents sometimes contaminate carcasses, depending on how the meat is processed, says Sharif. And this puts people who eat the chicken at risk of getting sick.
“Reducing Salmonella in the chickens' digestive tract could lead to more Salmonella-free chicken products on store shelves,” he says.
In the study, one-day-old chicks were treated with probiotics and, one day later, were given Salmonella. Improvements to the immune system of the chicks treated with probiotics were discovered weekly.
Giving chicks a blend of 29 probiotic bacteria led to a 95-per-cent reduction of Salmonella in the animals' digestive tract. There was also a reduction in the presence of Salmonella in the non-treated pen mates of the treated chicks, says Sharif.
The study looked at a repertoire of probiotics alone and in combination with prebiotics (food substances that promote the growth of beneficial bacteria in the intestines).
“We also found that the combination of prebiotics and probiotics could substantially reduce the existence of bad bacteria, those that are harmful for humans, in the chicken gut,” he says. “It's hoped that probiotics could actually work as a replacement for antibiotics, or at least be used to work in a complementary fashion with antibiotics.”
Probiotics are accessible from pharmacists who supply veterinary pharmaceuticals and are fairly inexpensive. The overuse of antibiotics in chickens is a concern that has already caused European countries to place restrictions on prophylactic antibiotic use in their poultry industries, says Sharif.
“If the same restrictions were enforced here, it would cause problems in the poultry industry, so it would be great if we could come up with a better system using probiotics to work hand-in-hand with antibiotics.”