Eggs are in many ways the ultimate food. They come in their own protective shell, they can be eaten alone for breakfast, lunch or dinner and they are one of the key and healthy ingredients to many dishes including desserts. In addition, eggs have historically served as an inexpensive source of high-quality protein, containing all the essential amino acids required by humans as part of a balanced diet.
Compared to other food animals, chickens are relatively easy to raise and provide eggs in a short period of time. However, like other foods, eggs are susceptible to food-borne pathogens and can cause illness if not handled properly. Every year, the Centers for Disease Control (CDC) and links hundreds (there are likely thousands that go un-reported) of Salmonella spp. outbreak cases to backyard poultry. It is also important to note that these cases are largely preventable via good husbandry and bio-security practices. Therefore, this article provides basic and practical advice on collecting eggs with an emphasis on food safety.
Dos and Don’ts
With the knowledge that food-borne pathogens like Salmonella are largely preventable, here are some tips on how to mitigate the risk of spreading disease through the egg collection process.
- Thoroughly wash your hands with soap and water before and after collecting eggs. By doing so, you reduce the risk of introducing pathogens from your home (i.e. handling contaminated meat, vegetables) to the eggs and vice versa. This is very important because once bacteria are introduced; it is very hard to get rid of them in your flock. Hand-sanitizers with an alcohol content of 60% or greater excel at killing bacteria and may seem like a good alternative to washing your hands, but they can quickly become ineffective if your hands are heavily soiled. For this reason, antimicrobial soap and water are preferred as they can remove and kill bacteria even when your hands are visibly dirty. To maximize your chances of getting rid of any bacteria from your hands follow soap and water washing with hand-sanitizer.
- Collect eggs at least twice a day. Frequent egg collection provides several benefits. While eggs have a natural barrier with antimicrobial properties around the shell, it begins to break down after 96 hours. After regularly checking for eggs, they should be refrigerated right away. Prompt refrigeration not only ensures fresher eggs; you will also prevent any possible bacterial load from dramatically increasing. Microbes can double in numbers in 20-30 minutes at optimal temperature (around room temperature for some bacteria)! However, if you refrigerate at 35 to 40°F, you can stop the bacteria from growing and thus reduce the bacterial load. Aside from ensuring good food safety, another reason to collect eggs regularly is to prevent the unwanted behavior of egg eating. This behavior generally occurs from hens accidently breaking eggs, so the less time your chickens have around eggs, the less likely they are to peck at them and become egg-eaters (a hard habit to beat.) It can also prevent chickens from becoming broody, another habit that is not easy to beat. With all these in mind, it makes sense why collecting eggs every day is important.
- Look out for abnormal eggs. It is easy to get in the routine of collecting eggs without really paying attention to them. However, taking the time to look for abnormal eggs can help you evaluate flock health. For example, cracked eggs can facilitate movement of Salmonella from the shell to the edible portion of the egg.
- Use clean containers when collecting eggs preferably plastic egg filler flats that are easy to clean and disinfect. It is very easy to get used to using the same container for collecting eggs without cleaning it daily, especially if it does not appear dirty. However, harmful bacteria such as, Salmonella and Campylobacter, have been known to persist in the environment for months! Therefore, it is a good idea to clean and disinfect the collecting vessel each time before use to avoid cross-contamination. Reusing paper cartons to collect eggs should be avoided as they cannot be disinfected.
- “Hunt” for eggs, make sure your hens are using their nest boxes. Letting them lay their eggs where they please may seem like fun or “natural”, but daily egg hunts are not always fun and “floor eggs” are typically dirtier and more contaminated than eggs in nest boxes. In addition, nest boxes provide a cleaner and safer environment away from dirt and predators. This is very important for predator control as well. Once predators are attracted and realize there is access to food (i.e. eggs) they will keep coming back.
- Keep eggs that are very dirty, have cracks or holes. If there is dirt present, consider dry cleaning with a cloth, or as a last resort sandpaper. Sandpaper will wipe off the cuticle or bloom. The cuticle has antibacterial properties. If this type of cleaning doesn’t work, from a food safety perspective it’s best to throw the eggs out.
- Washing eggs at home is not recommended. If done incorrectly washing can actually drive more bacteria into the egg. In general eggs have to be washed to be sold commercially in the United States. However, washing eggs is not a panacea in that if done improperly bacteria can be driven inside the eggs through the pores. Therefore, unless you are selling your eggs our recommendation is to not wash the eggs you collect from your backyard flock.
Although the above tips can help greatly reduce the number of bacteria found in your eggs, food safety does not stop there. Backyard chicken keepers should also practice proper egg handling (such as regular cleaning of surfaces in contact with eggs) and cooking (heating the eggs to 165 degrees F) to fully enjoy this wonderful food item from your chickens.
This article was written by Dr. Maurice Pitesky at the UC Davis School of Veterinary Medicine.