title: Effects of long- or short-haul transportation of slaughter heifers and cattle liner microclimate on hide contamination with Escherichia coli O157.
abstract: Effects of cattle transportation on hide contamination with Escherichia coli O157 have been variable, and the present study was designed to clarify relationships among duration of transport, microclimate, and environment within the trailer and contamination of hides with E.  coli O157. Crossbred Angus heifers from a feedlot in southern Alberta were sorted into 10 replicate loads containing 45 animals (short haul, 621.5 ± 2.1 kg of body weight) or 46 animals (long haul, 576.0 ± 1.7 kg of body weight). Long-haul trips (n = 5) were made in  July and August to slaughter plant A, whereas short-haul trips (n = 5) were made in October to slaughter plant B. The same trailer unit and driver were used for all loads. Data loggers were located in the ceiling of each compartment of the trailers to record ambient temperature and  relative humidity. Each heifer was swabbed on the perineum on-farm prior to loading and immediately after stunning at the slaughter plant (an average 12-h transport for long haul and 1-h transport for short haul). Swabs were transported on ice before immunomagnetic separation for detection  of E. coli O157. Transportation did not affect prevalence of hide contamination with E. coli O157, although 80% of long-haul swabs were positive on-farm compared with 26% of short-haul swabs, due to seasonality of shedding E. coli O157. Cattle transported in the nose compartment  had fewer positive hide swabs (P < 0.05) than cattle in the deck or belly compartments during long-haul trips, even though the nose had a higher (P < 0.05) temperature-humidity index than the other compartments. Prevalence of hide contamination varied widely among  loads even when the organism was at seasonally low levels. This suggests that the feedlot pen has a greater effect on hide contamination at the slaughter plant than transportation factors including temperature-humidity index, loading density, and duration of transport.
authors: Alberta Agriculture and Rural Development, Agriculture Centre, 5401 First Avenue South, Lethbridge, Alberta, Canada. kim.stanford@gov.ab.ca
authors: K
authors: K
authors: Stanford
authors: M
authors: M
authors: Bryan
authors: J
authors: J
authors: Peters
authors: L A
authors: LA
authors: González
authors: T P
authors: TP
authors: Stephens
authors: K S
authors: KS
authors: Schwartzkopf-Genswein
mesh_terms: D000003:Abattoirs; D000818:Animals; D002417:Cattle / Q000382:microbiology*; D015169:Colony Count, Microbial; D019453:Escherichia coli O157 / Q000254:growth & development / Q000302:isolation & purification*; D005243:Feces / Q000382:microbiology; D005260:Female; D005506:Food Contamination / Q000517:prevention & control*; D006801:Humans; D006920:Hygiene; D015995:Prevalence; D012621:Seasons; D012867:Skin / Q000382:microbiology*; D013997:Time Factors; D014186:Transportation