Bacteria in swine altered by growth promoters
Researchers from the University of Minnesota's College of Veterinary Medicine have confirmed that antimicrobial growth promoters given to swine can alter the bacteria present in their intestinal track.
The research, instigated by a concern about the use of antibiotics in animal production, found that some antimicrobial growth promoters resulted in an accelerated rate of growth and development in swine, and the findings are published in the Proceedings of the National Academy of Sciences.
The effects of the antimicrobial Tylosin were observed in the faeces of commercial pigs on two farms in Minnesota. In young pigs receiving Tylosin, the composition of their intestinal bacteria changed so that it was similar to that naturally accredited to an older animal.
Professor Richard Isaacson led the study. He commented: "Bacterial composition drives the ability of animals to grow and thrive by contributing to digestion and metabolism," said Isaacson. "Because the bacteria in more mature animals break down growth-promoting components in food more efficiently, younger animals are able to achieve adult size and an adult-like metabolic rate more quickly."
Veterinary practices are being urged to help owners safely dispose of any unused and expired pet medicines - not just antibiotics - during November's Animal Medicines Amnesty. 
