The Long, Hard Road to Beef Safety: Beef Recalls Spike in 2007

Cattle presented for slaughter typically come from dairy farms, beef cattle farms, or feedlots. About 80% of all cattle slaughtered in the United States come from feedlots. They include heifers, steers, yearling cattle, bulls, or cull dairy cows. When cattle arrive at the slaughterhouses, their hides and hooves are covered with mud, manure, bedding, and other materials that contain large numbers of microorganisms. The bacterial load depends on herd- or farm-management practices, transport and holding practices, and feedlot conditions and controls. Season of the year and age and type of cattle are other factors that will influence the microbial load. Hide preparation prior to slaughter is a huge task.

The slaughter, processing, and distribution of meat from culled breeding cattle and feedlot cattle differ; sampling evidence has suggested there may be differences in E. coli O157:H7 prevalence between these two types. A risk assessment by the FSIS Office of Public Health and Science and other federal agencies determined that the prevalence of E. coli O157:H7 is significantly higher for feedlot cattle than for breeding cattle. It also found that the prevalence of E. coli O157:H7 is higher for both types of cattle during the warmer months occurring from June through September than for the months from October through May.

An effective way to detect the presence of E. coli is to micro-sample carcasses. This is a good barometer for slaughterhouses to use to measure their practices because it focuses on the efficacy of their interventions. The rump, brisket, and flank are tested because these parts of the carcass are most likely to become contaminated during dressing procedures. Testing should begin with the hide and go from there, with the same carcass being trailed before and after critical control points (CCPs) and critical limits, including taking samplings in the hot boxes.

A great deal of testing and evaluation has been conducted to determine the most effective methods for removing mud, fecal matter, and other extraneous materials from the cattle’s hide prior to and after the knocking process. Inclement climates and other unique geographic and logistic conditions restrict, to varying degrees, some hide interventions that can be used before knocking.

The slaughterhouse continuum of knocking to hot boxing should be continually reassessed. Interventions such as using antibacterial cabinet sprays before hides are removed cut bacteria loads dramatically, resulting in cleaner carcasses downstream. Positive airflows and walls that completely separate hide-on and hide-off areas are imperative. Established interventions such as pre- and post-evisceration hot water and steam vacuuming, antibacterial sprays, hot water pasteurization cabinets, and hand trimming reduce or eliminate pathogens, making them the CCPs of choice for slaughterhouses. Finally, cold chain-management begins in the hot boxes, with the surface of the hanging carcasses cooled to 40°F in approximately 24 hours.

Training and Sanitation

Although many factors can be accounted for and controlled to a certain extent, slaughterhouse workers remain a huge and undervalued variable. Management must view workers as latent vectors of contamination in the otherwise sterile conditions of exposed carcasses. Training, training, and more training must be conducted regularly to combat cross-contamination concerns. Two knife, hook, and steel practices should be used at each processing station (beginning with the stickling and ending at the final trim) with alternate tools sterilized in hot water.

Employee turnover plays a starring role in the beef industry’s woes as well. Homeland Security raids (or the threat of them) have depleted the supply of experienced workers and their time-acquired skills. Employers at USDA-inspected establishments have been, and will continue to be, singled out by the Immigration and Naturalization Service for hiring illegal immigrants. Depending on the political tide of the country, this issue will remain in the forefront of the beef industry. It will affect the safe production of meat products in varying degrees at all levels of beef processing.