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Probiotics Useful But No Substitute For Antibiotics

“We need to use

antibiotics effectively.”


The TV ad showing a person’s tummy doing a belly dance after eating yogurt may be coming to a hog barn near you.

That particular yogurt contains probiotics – beneficial bacteria aimed at improving digestion and general wellbeing.

Probiotics are big these days as North Americans seek “natural” ways to achieve a healthy inner ecosystem through diet.

Now these healthy bacteria are finding their way into animal feed, too.

A recent livestock nutrition conference in Winnipeg heard that probiotics (and their cousin prebiotics) are increasingly used in livestock feed supplements as a means of improving animal health and performance.

Most significantly, they are seen as a partial replacement for sub-therapeutic levels of antibiotics in animal rations.


Probiotics are live organisms (bacteria or yeast) fed to animals to grow in the digestive tract. Prebiotics are carbohydrates that stimulate the growth and activity of certain bacteria in the colon. Both increase populations of desired bacteria. This improves digestion and helps guard against disease by inhibiting the development of bad bacteria (e. g., salmonella).

Probiotics and prebiotics can be fed to swine, dairy cattle and poultry in hopes of increasing gain, improving nutrient utilization and feed conversion and, in the case of pigs, increasing weaning weights, the conference heard.

The jury is still out on whether prebiotics are as effective as claimed. But there’s a “solid biological basis” for believing probiotics can do what they’re supposed to, said James Pettigrew, a University of Illinois animal scientist.

At the same time, they should not be seen as a substitute for antibiotics, Pettigrew said.

The widespread practice of feeding antibiotics to livestock as a growth promoter has come under fire in recent years for allegedly contributing to antimicrobial resistance in animals and even humans.

The European Union banned the use of antibiotics as growth promoters January 1, 2006. It was the EU’s final step in phasing out the use of antibiotics for non-medicinal purposes in livestock.


Pettigrew warned against throwing the baby out with the bathwater, saying European farmers find they have more sick animals now that the non-therapeutic use of antibiotics has been abolished.

For that reason, Pettigrew said he opposed wholesale elimination of non-therapeutic antibiotics.

“We should use antibiotics only when they’re needed and effective. But the experience in Europe reminds us that growth-promoting antibiotics are not just growth promotants. They’re also very important prophylactic agents,” he said.

“We need to use antibiotics effectively, not only to treat sick animals but to keep animals from getting sick.

“For the time being, and for the foreseeable future, we need to pay close attention to appropriate use of antibiotics. But at the same time, we need to look for other methods to improve the health of animals.”

That includes diet, said Pettigrew, adding the industry should see feed as an integral part of a herd health program instead of separate from it.

But diet is only part of herd health, said Pettigrew. Other management practices to keep pigs healthy can include all-in all-out flow, biosecurity, sanitation and vaccines.

If producers do give antibiotics to their animals, they might do so more judiciously, Pettigrew added.

He said antibiotics are appropriate for newly weaned pigs because overall immunity is lowest at the time of weaning. But there’s less justification for the continuous feeding of antibiotics to feeder pigs. [email protected]

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