This summer half a billion industrially produced eggs were recalled due to being tainted with salmonella. What in the world is going on? Salmonella bacteria commonly live in the intestines of humans and animals, including chickens. Several strains of salmonella survive in soil, water, and any place else animal or human feces are found. Strains that cause no symptoms in chickens may make people sick, and vice versa.
When a creature eats something that’s been contaminated with salmonella, the bacteria may proliferate in the digestive tract and cause a diarrheal disease called salmonellosis. The number of bacteria that must be swallowed to cause illness depends on the bacteria’s strain, as well as the age and health of the individual (human or chicken) doing the swallowing.
Chickens that carry salmonella can appear perfectly healthy, but may not remain so if they come under heavy stress due to such things as being overcrowded, deprived of feed, treated with drugs, force molted, or inhumanely transported. The bacteria spread by contact with infected chickens; by means of contaminated droppings in litter, drinking water, and damp soil around waterers; mechanically by flies, rodents, wild birds, used equipment, shoes, truck tires, and the like. Salmonella may also be present in poultry rations containing contaminated meat by-products. Hold that thought.
Back in the old days, salmonella typically contaminated an egg when chicken poop got on the shell. Either the bacteria penetrated the shell and multiplied within the egg, or it fell off the shell into the cooking bowl when the egg was cracked open. Prevention was simple: keep nests clean and throw away eggs laid on the floor or otherwise covered with chicken poop.
Somewhere along the line, industrialized layer strains got their ovaries contaminated by salmonella bacteria. So these days the likely cause of contamination from an industrially produced egg is that the yolk got infected as the egg was being formed inside the body of an infected hen. Why or how this came about, no one knows (or isn’t saying). But let’s look at some facts.
Industrialized hens are typically overcrowded and overstressed, leading to reduced resistance to disease. Most backyard hens are maintained in a cleaner environment, are handled gently, and in general live relatively stress-free lives, helping them more readily resist disease.
Industrially produced eggs are packaged and repackaged by different distributors so they may be sold under different brand names. All this handling, travel, and the possibility of inconsistent refrigeration gives any salmonella that might be present in an egg plenty of time to proliferate. Backyard eggs typically go directly from a clean nest into the frying pan or the fridge. When you produce your own food, you have an incentive to make sure it’s handled safely.
A few moments ago I mentioned that salmonella may be spread in rations containing contaminated meat by-products. Well, as this issue of Backyard Poultry goes to press, the United States Food and Drug Administration is investigating the likelihood that the massive egg recall was caused by contaminated rations fed to the layers in question.
A Backyard Poultry reader recently asked me why I use layer ration containing no animal by-products, when I have stated many times that chickens are not vegetarians and therefore require animal protein in their diet. The reason is simply that I don’t trust animal protein sources used in any commercial ration. I feed an all-vegetable based ration because my chickens roam pasture and orchard and get plenty of animal protein by eating lots of bugs, worms, and other small protein-laden critters. Chicken keepers whose flocks lack foraging opportunities must either provide animal protein in some form (such as purposely raising worms or grubs) or feed a ration containing animal protein.
So, can backyard hens carry salmonella? Certainly.
Are eggs from backyard hens likely to make you sick? Probably not, for all the above reasons and one more: Unless you acquired your chickens yesterday, your daily exposure to the microbes they carry has allowed you to develop an immunity of sorts. Compared to someone who never sees a chicken, you are therefore less likely to be affected by inadvertently swallowing the occasional bacteria.
Gail Damerow is the author of Storey’s Guide to Raising Chickens, The Chicken Health Handbook, Draft Horses and Mules, Fences for Pasture and Garden, The Perfect Pumpkin, Your Goats, and Your Chickens. She is a regular contributor to Backyard Poultry magazine and former editor of Rural Heritage magazine.
Gail and her husband operate a family farm in Tennessee where they raise chickens, guinea fowl, turkeys, rabbits, and dairy goats.
|Safe Egg Handling
By Lisa Jansen Mathews
At the center of safe egg handling is the natural protective coating on an egg, called the cuticle or bloom. It’s a water soluble, proteinous barrier that fills the thousands of microscopic pores in an egg’s shell. Without the cuticle, bacteria would get into the egg through the pores and moisture would evaporate from within the egg. So the answer to safe and fresh egg handling seems simple: Protect the cuticle and it will protect you.
Start by keeping nests scrupulously clean. Remove manure from the nest boxes when the henhouse is opened in the early morning to reduce the need for cleaning eggs. Use a nesting material that lends to easy manure removal. I find pine shavings easier than straw. All I need is a gloved hand and small bucket for daily manure removal. I also recommend raking the top of floor litter since clean chicken feet preserve a clean nest.
Furthermore, do not overpopulate your henhouse or nest boxes. Provide at least one
nest box for every four hens.
No matter how clean you keep the coop and nests, some eggs will get soiled. A small amount of moist manure may be removed with a paper towel. If the manure is dry, use a fine grit sandpaper or a brush; the cleaned egg will stay safe and fresh for weeks. Water is not always necessary, and will certainly remove the bloom. If you have to clean a shell with water, use the egg immediately. A severely soiled egg should be discarded (and measures taken to avoid more of the same in the future). When in doubt, heating an egg or egg dish to 160 degrees Fahrenheit will eliminate all possibility of danger.
Adapted from "A Clean Egg is a Safe Egg," April/May, 2008 Backyard Poultry