How do pig farms maintain low Salmonella prevalence: a case-control study

Area of Science:

• Veterinary Microbiology
• Animal Husbandry
• Food Safety

Background:

• UK pig farms face high Salmonella prevalence, necessitating identification of low-prevalence strategies.
• Investigating farms with sustained low Salmonella seroprevalence is crucial for effective control.

Purpose of the Study:

• To compare management and risk factors between UK pig farms with consistently low Salmonella seroprevalence (Platinum farms) and control farms.
• To identify key differences associated with maintaining low Salmonella prevalence in pig production.

Main Methods:

• Comparison of 19 Platinum farms (low seroprevalence <10% over 4 years) with 38 matched Control farms.
• On-farm sampling including floor faeces and environmental samples.
• Analysis of risk factors, performance data, and pig movement records.

Main Results:

• Control farms had significantly higher Salmonella-positive faecal samples (12.1% vs 0.4%) and more public health serovars.
• Risk factors for high prevalence included pelleted feed, external feed deliveries, and regular antibiotic use.
• Platinum farms exhibited better slaughter live weight performance.

Conclusions:

• Maintaining very low Salmonella prevalence on UK pig farms is achievable.
• Specific management practices and reduced exposure to risk factors are key to low prevalence.
• Further research into pig movement is needed to fully understand Platinum farm status.