UNIVERSITY PARK, Pa. — Antimicrobial resistance is an increasingly serious threat for public health, and the use of antimicrobials in livestock feed has been a major contributing factor in the emergence and spread of antimicrobial resistance to many drugs, according to the U.S. National Institutes of Health. The poultry industry is evolving toward antibiotic-free production to meet market demands and decelerate the spread, and Penn State researchers are helping to identify and better understand alternative approaches.
The growing need for antibiotic-free products has challenged producers to decrease or completely stop using antimicrobials as feed supplements in the diet of broiler chickens to improve feed efficiency, growth rate and intestinal health. Led by Erika Ganda, assistant professor of food animal microbiomes, a Penn State research team conducted a study of natural feed additives that are promising alternatives to substitute for antimicrobial growth promoters.
In findings available online now that will be published in the May issue of Poultry Science, the researchers characterized the effects of a probiotic and a blend of essential oils on broilers’ growth and gut health. The team found that supplementing the diet of young chicks with a probiotic over 21 days significantly boosted the abundance of beneficial intestinal microorganisms.
Overall, according to Ganda, research like the work her team conducted is urgently needed to help producers make decisions at the farm. However, she added, the use of these feed additives in broiler production is still in its early stages, and more studies to evaluate the health outcomes, mechanisms and consequences for antimicrobial resistance prevalence will be necessary to better understand the role of feeding antimicrobial growth promoters alternatives on the gastrointestinal tract of broilers.
“Because the elimination of antimicrobial growth promoters use is associated with increases in disease and a decrease in growth performance in chicks, antibiotic-free alternative approaches to enhance intestinal health and improve growth performance are of great interest to the poultry industry,” she said. “The claim that a product is ‘natural’ does not make it necessarily more beneficial than antibiotics, so we conducted this experiment to answer this question.”
In the research, spearheaded by Ana Fonseca, graduate assistant in Ganda’s research group in the College of Agricultural Sciences, a total of 320 one-day-old chicks were raised for 21 days in 32 randomly allocated cages. Treatments consisted of four experimental diets: a standard diet; and a standard diet mixed with the antibiotic bacitracin methylene disalicylate, or an essential oils blend of oregano oil, rosemary and red pepper, or the probiotic Bacillus subtilis.