Skip to main content
ARS Home » Midwest Area » Ames, Iowa » National Animal Disease Center » Food Safety and Enteric Pathogens Research » Research » Publications at this Location » Publication #124339
Title: THE EFFECT OF LAIRAGE ON SALMONELLA ISOLATION FROM MARKET SWINE

Author
item Hurd, Howard
item MCKEAN, J - IOWA STATE UNIVERSITY
item Wesley, Irene
item KARRIKER, L - SEABOARD FARMS HEALTH

Submitted to: International Symposium on Epidemiology and Control of Salmonella in Pork
Publication Type: Proceedings
Publication Acceptance Date: 9/5/2001
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: This study's objective was to evaluate the effect of lairage (holding > 12 h during transport to slaughter) on Salmonella isolation from market swine. We tested 30 marketbound pigs (~110 kg) on each of 10 occasions from an Iowa farrow-to-finish operation with ~600 sows. On the farm, fecal samples (1 g) were collected for culture of Salmonella. Pigs were alternately assigned to a lairage treatment group (holding in a clean, disinfected facility) or a control group (remain on the farm). Treatment pigs were collected from different pens, mixed during loading, and fasted during lairage. Control pigs remained in their original pens, on full feed. After ~18 hours, both groups were transported in clean, disinfected research trailers to a large midwest abattoir, and slaughtered in the routine manner. Salmonella enterica Derby was the only serotype isolated from farm fecal samples. However, multiple different serotypes (n = 17) were isolated from these pigs at slaughter. The predominate serotype isolated at the abattoir varied by week of the study, suggesting a Salmonella source other than the farm. The treatment pigs had lower Salmonella isolation rates than nonlariaged pigs (P < 0.05). This study suggests that the physiological effects of 18 hours lairage do not increase shedding. In addition, it raised the possibility that pigs became internally contaminated with Salmonella, after leaving the farm, possibly while in the abattoir holding pens. These experiments show that market swine can become infected during routine resting or holding periods when exposed to relatively low levels (10**3 CFU) of Salmonella in the simulated preslaughter environment.