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RANCH
After calves are weaned, they munch grass in a pasture. When they weigh about 500 pounds,
some are sent to a feedlot. Others are kept for "backgrounding"---getting accustomed
to their future corn-based meal plan---until they weigh 650 or 700 pounds.
WHAT CAN GO WRONG
E. coli O157:H7 is present in an estimated two-thirds of breeding herds.
Though potentially deadly to humans, the germ doesn't sicken cattle, so it's not possible
to cull animals that carry it, and it spreads so fast from animal to animal that testing
would be futile.
FEEDLOT
Cattle from many ranches converge at feedlots, where they consume a corn-based diet
designed to make them gain weight fast, usually with help from hormones and antibiotics.
In three to six months, they put on 400 to 500 pounds. Crammed in pens, they step in
manure and drink from common water troughs.
WHAT CAN GO WRONG
E.coli O157:H7 is present in about 90 percent of feedlots. The germ is also in feed
bunks and water troughs because cattle repeatedly bring cud from stomach to mouth for
more chewing.
SLAUGHTER
When cattle reach 1,100 pounds or so, they're slaughtered, usually in plants that process
more than 1,000 animals a day. Smaller plants tend to kill culled dairy cattle, whose meat
is especially likely to end up as ground beef. USDA inspectors check live animals and remove
any that look ill or infected. After an animal is killed, its hide and internal organs are
removed, and its carcass is sawed in half. USDA inspectors check it again, making sure
any soiled spots and visible flaws are cut away. The carcass is cleaned. In large plants,
that usually includes "steam pasteurization," during which sides of beef are exposed to
pressurized steam. Some plants also spray the carcass with a weak acid solution, which
retards bacterial growth. Then the sides are chilled for a day or two, and the USDA conducts
random tests for Salmonella.
WHAT CAN GO WRONG
Many cattle arrive at the slaughterhouse with E.coli O157:H7 on their hides.
In the process of dehiding, germs can contaminate the underlying fat and muscle, which are
normally sterile. The bacteria can also become airborne, and waft onto previously clean
carcasses. About 1 percent of the time, studies suggest, a slip of the knife during
evisceration perforates the bowel, spilling bacteria.
FABRICATION
This occurs at the slaughtering plant or elsewhere. The sides are disassembled into the
four primal cuts (round, loin, rib, and chuck), which may be segmented further or sent to
stores. Leftover bits of meat go into giant stainless-steel "combo bins" or into boxes for
shipment elsewhere. At the end of each workday, a crew power-washes the fabrication area with
hot water and sanitizers.
WHAT CAN GO WRONG
If previous steps haven't rid carcasses of harmful bacteria, it's too late now.
And with the meat constantly being handled, opportunities for cross-contamination abound.
The cleanup may miss bits of germladen meat lodged in machinery. If meat from a contaminated
carcass gets into a combo bin, it can taint the other meat in there. Government scientists
estimate that between 23 percent and 43 percent of bins contain at least one
E.coli O157:H7 organism.
GRINDING
Meat is ground at the slaughterhouse; at grinding plants, where bins can be mixed to produce
ground beef with a specified fat content; or at stores, which grind trimmings with coarsely
ground meat received from processing plants. The USDA randomly tests for E.coli
O157:H7 and Salmonella in meat at grinding plants and stores.
WHAT CAN GO WRONG
Mixing dirty meat with clean will contaminate a whole batch. If grinders aren't sanitized
between loads, contamination can carry over to the next batch. If meat gets warmer than
about 40 degrees for extended periods, bacteria can multiply rapidly. Plant workers can
cross-contaminate meat if they aren't careful to wash hands, surfaces, and knives.
SELLING
Stores usually package ground beef on the premises, to meet their customers' needs, but
increasingly this step involves simply setting case-ready packages in the meat case.
WHAT CAN GO WRONG
Cross-contamination opportunities abound, and lax temperature control can allow germs
to grow.
PREPARING
Control passes to the customer.
WHAT CAN GO WRONG
Meat can quickly become too warm in the shopping cart or car: A 1999 study by Audits
International, a quality-control consulting firm, found that the temperature of
refrigerated products rose an average of 9 degrees between store and home. As ground beef
is being prepared, its juices can contaminate other foods via countertops, cutting boards,
utensils, or unwashed hands. Patties can be undercooked, allowing germs to survive
and multiply. A 1998 survey found that although more consumers were thoroughly cooking
ground beef, 16 percent still served it rare or medium-rare. For help in making sure the meat
you cook is safe to eat, see the Recommendations Page.
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