Published by Ontario Veterinary College (519) 824-4120, Ext. 54401

January 19, 2007

Probiotics Help Produce Safer, Healthier Chickens

Giving chickens probiotics – dietary supplements that contain live beneficial bacteria – stimulates their immune system and reduces the Salmonella bacteria in their gut by more than 99 per cent, an Ontario Veterinary College professor and an Agriculture and Agri-Food Canada food researcher have 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,” said Dr. Shayan Sharif, Pathobiology, who worked in collaboration 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, said 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, to less than one per cent, the level of colonization of Salmonella in the chicken gut. The gut contents sometimes contaminate carcasses, depending on how the meat is processed, which puts consumers at risk of getting sick, said Sharif. “Reducing Salmonella in the chickens’ digestive tract could lead to more Salmonella-free chicken products on store shelves.”

In the studies, one-day-old chicks were treated with probiotics and one day later were given Salmonella bacteria. The immune status and Salmonella bacterial load in the chicks was examined at various intervals and the positive results surfaced quickly, said Sharif.

Sharif and Chambers’ 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 reduce the existence of bad bacteria − those that are harmful for humans − in the chicken gut substantially,” said Sharif.

“There’s a hope that probiotics could actually work as a replacement for antibiotics, or at least be used to work in a complementary fashion with antibiotics,” he said. Probiotics are available from veterinary pharmaceutical suppliers 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 within their poultry industry.

“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,” said Sharif.