Penn State Study Finds Age Influences Chicken Antimicrobial Resistance More Than Feed Additives

Poultry producers have sought alternatives to antibiotics in animal feed, such as probiotics and essential oils, to address concerns regarding antibiotic resistance. Researchers at Penn State investigated whether these feed additives influence the diversity of antimicrobial resistance genes in broiler chickens. The study compared the effects of feeding chickens an antibiotic, a probiotic, or essential oils on their resistome, defined as the collection of antimicrobial resistance genes.

The findings indicated that the type of feed additive did not significantly affect the overall diversity of these genes. Instead, the age of the chickens was found to have a much stronger impact on the resistome as the birds grew. This suggests that developmental factors play a more significant role in the variation of antimicrobial resistance genes than the specific dietary supplements used.