Table 2.

Prevalence of Salmonella-positive LNs samples¹ by chilling method² and region for market hogs³

	Region
	Northern	Southern
Chill type
Conventional	20.0 (10/50) A	20.0 (10/50) A
Blast chill	1.3 (1/77) B	0.0 (0/25) A
Other	2.7 (2/75) B	12.0 (3/25) A

a,b: Values within a column lacking a common letter differ (P < 0.017).

¹A total of 21 (n = 8 northern market hog, n = 4 northern sow, n = 4 southern market hog, and n = 5 southern sow) commercial harvest and processing facilities participated in the study; the remaining 12 facilities either declined or were no longer in operation. At each commercial facility, market hogs or sows were harvested and left and right superficial inguinal LNs (n = 1,014 LNs) were removed. Within animal, left and right LNs of each type were pooled (n = 507 total samples).

²Carcass chilling methods were defined as follows: 1) conventional—standard cold storage unit without forced air circulation or water spray; 2) blast chill—cold storage unit with forced air circulation and without water spray; or 3) other—conventional or blast chill with water spray or other quick chill system.

³Carcass chilling methods were only documented for establishments harvesting market hogs, as all sow carcasses were hot-boned.