April 25, 2024
US study finds salmonella rates higher on larger poultry farms
Researchers at North Carolina State University, US, conducted a comparative study of Salmonella prevalence between differently sized poultry farms, revealing that larger commercial farms had higher rates of Salmonella in faecal and environmental samples compared to smaller backyard farms, Phys.org reported.
The study, led by Jessica Parzygnat, a PhD graduate from NC State, focused on broiler chickens raised for meat consumption, examining 10 backyard and 10 commercial flocks. Backyard flocks ranged from 22 to 1,000 birds, all raised outdoors, while commercial farms housed tens of thousands of birds indoors.
Faecal samples from birds and environmental samples such as litter, soil, and feeders were analysed for Salmonella presence, alongside other pathogens. The study aimed to understand Salmonella spread in both types of production systems and shed light on pathogen prevalence.
Results showed lower Salmonella rates on backyard farms (19.1% of samples) compared to commercial farms (52.3% of samples), consistent with previous studies. However, both types of farms exhibited multidrug-resistant Salmonella strains, indicating resistance to three or more antibiotic classes, despite antibiotics being sparingly used in commercial farms and not at all in backyard farms.
Parzygnat emphasised the importance of precautionary measures for consumers, such as thorough cooking of poultry and preventing cross-contamination during handling and preparation. Salmonella, naturally occurring in bird gastrointestinal tracts, often shows no signs of illness in birds, making antibiotic resistance a significant concern for infection.
The study, published in Foodborne Pathogens and Disease, underscored the need for vigilant management practices on both small and large poultry farms to mitigate Salmonella risks and antibiotic resistance. Sid Thakur from NC State is the corresponding author, with co-authors from NC State, South Dakota State University, and the Walter Reed Army Institute of Research.
- Phys.org
