Food Safety Markets Feedlot or Suckler

Study Highlights Need for Caution over Beef Pathogens

MEXICO - Researchers have found that Salmonella prevalence in cattle and on carcasses in a vertically integrated feedlot and harvest plant of more than 90 per cent in faeces and on hides. The overall prevalence of E. coli O157:H7 was lower with a maximum of 11.7 per cent for hides.

8 May 2013

2 minute read

North America

From their study of Salmonella and Escherichia coli O157:H7 prevalence in cattle and on carcasses in a vertically integrated feedlot and harvest plant in Mexico, researchers from Texas Tech University concluded that the results serve as a warning as to the risks of contamination in meats for these pathogens and the importance of following good manufacturing practices during beef production processes.

In Journal of Food Protection, Mindy Brashears and co-authors report their work to determine the prevalence of Salmonella and E. coli O157:H7 in cattle feedlots and the impact of subsequent contamination on carcasses in a Mexican Federal Inspection Type Standards harvest facility.

A total of 250 animals were tagged and sampled in each step of the slaughter process. Samples were taken from hides and faecal grabs, and composite samples were taken from three anatomical carcass sites (hindshank, foreshank and inside round) during the slaughter process, at pre-evisceration (PE), prior to entering the hot box (PHB), and after 24 hours of dry chilling (DC).

Additionally, 250 faecal samples were collected from the feedlot (FL), holding pens (HP) and intestinal faeces (IF) and water samples were taken from the HP area.

E. coli O157:H7 and Salmonella detection were carried out with the BAX System, immunomagnetic separation and conventional methods.

Overall Salmonella prevalence was 52.5 per cent. The highest prevalence (92.4 per cent) was found on hides, followed by faeces from the HP (91.0 per cent), FL (55.56 per cent), PE (49.0 per cent), IF (46.8 per cent) and PHB (24.8 per cent), for all sampling periods combined. The lowest prevalence of 6.0 per cent was found after DC.

The overall prevalence of E. coli O157:H7 was as follows: 11.7 per cent for hides, 5.2 per cent for IF, 2.7 per cent for FL, 2.0 per cent for HP, 0.8 per cent for PE, 0.4 per cent for PHB and 0.4 per cent for the cooler.

High prevalence of Salmonella in IF and on hides present a significant risk factor for contamination by Salmonella at the different processing steps, according to the researchers.

They added that the results serve as a warning as to the risks of contamination in meats for these pathogens and the importance of following good manufacturing practices during beef production processes.

Reference

^{Narvaez-Bravo, C.;, Miller, M.F., Jackson, T., Jackson, S., Rodas-Gonzalez, A., Pond, K. Echeverry, A. and Brashears, M.M. 2013. Salmonella and Escherichia coli O157:H7 prevalence in cattle and on carcasses in a vertically integrated feedlot and harvest plant in Mexico. Journal of Food Protection, Number 5, May 2013, 786-795. DOI: http://dx.doi.org/10.4315/0362-028X.JFP-12-079}