October 29, 2008
Hops contain substances that control pathogenic bacteria in the intestines of chickens, Agricultural Research Service (ARS) scientists and cooperators have reported.
Certain
bacteria in the intestines of chickens not only can cause contamination
of meat during processing, but also may pose major production losses by
causing disease in the broiler chicken.
Currently, poultry
producers use sub-therapeutic amounts of antibiotics in poultry feed as
growth promoters and to control bacterial pathogens or parasites.
However, bacteria can become resistant to the antibiotics, so ARS
scientists are looking for alternatives.
The hop plant (
Humulus lupulus)
contains bitter acids known to be potent antimicrobials. One of these
compounds, lupulone, was thought to control levels of the
disease-causing agent
Clostridium perfringens in chickens.
ARS
scientists, working under a cooperative research agreement with hops
producer Hopsteiner in Yakima, Wash., examined the effect of feeding
different concentrations of lupulone to broiler chickens to determine
the compound's impact on
Clostridium populations in the intestinal tracts of birds inoculated with
C. perfringens.
A research team led by microbiologist Gregory Siragusa, formerly of the ARS Poultry Microbiological Safety Research Unit in Athens, Ga., in collaboration with Gerhard Haas of Fairleigh Dickinson University in New Jersey, delivered different concentrations of lupulone via water to chickens inoculated with
C. perfringens. After 22 days—the timeframe associated with clostridial disease in broiler chickens—
C. perfringens
counts were significantly reduced in the lupulone-treated group
compared to another group of chickens that did not receive the lupulone
treatment. The reductions ranged from 30 to 50 percent.
According
to the team, the potential for lupulone as an antibiotic alternative in
poultry rearing is feasible based on these results.
This research was published in the
Journal of Antimicrobial Chemotherapy.
ARS is a scientific research agency of the U.S. Department of Agriculture.
