The Chicken and the Egg

Abigail Martin
In 2018, approximately seven million laying hens in Wisconsin produced over two billion eggs.

It’s the age-old question: what came first, the chicken or the egg? While we may never know the answer to this question, I am thankful both the chicken and the egg have found a home in Wisconsin agriculture. In 2018, approximately seven million laying hens produced over two billion eggs. That’s an average of 286 eggs per chicken per year. Thanks to these hard-working hens, residents all over our state are able to enjoy fresh, Wisconsin eggs.

According to National Agriculture in the Classroom resources, most laying hens in the U.S. are Single-Comb White Leghorns. This variety is one of 12 known variations of the Leghorn breed. The Leghorn chickens originated in Italy, but can be found throughout the world today. Single-Comb White Leghorn chickens lay white eggs, and are recognized for their high egg production. All varieties of Leghorn chicken have a red wattle (excess skin underneath the beak of the bird), white earlobes, and either a single or rose comb (excess skin on top of the bird’s head, working in conjunction with the wattle to regulate body temperature).

Many hens lay their first egg around four and a half months of age. Initial eggs may be irregular, possibly small in size or containing a double yolk. After a week or so, egg production should become more consistent. At peak performance, and average hen will lay one egg every 28 hours.

After an egg is laid, it is cleaned and sanitized in water heated to more than 90 degrees Fahrenheit. Once the egg is washed, it is analyzed for any dirt spots. If an egg is detected with dirt spots, the egg is routed back to the washer.  In some cases, oil is used to protect shell eggs and is applied in a manner that prevents egg contamination and preserves egg quality. Throughout the collection and washing process, eggs must be kept at an average temperature of 60 degrees or below, but must be brought to 45 degrees or colder within 36 hours after collection.

Many hens lay their first egg around four and a half months of age.

Next up, it’s time to check for cracks. In modern operations, to detect shell cracks, eggs are checked sonically. In a matter of seconds, tiny probes tap each egg 16 times and ‘listen’ for the sound it makes. A fully intact egg has a high pitch and a sustained ring. A thud indicates a crack and the egg won’t be packed. During this grading process, eggs are also sorted according to weight. This weight determines how eggs are labeled and packaged, and breaks down as follows. The smallest eggs fall into the medium category, weighing approximately 21 ounces per dozen. Large and extra-large eggs fall in the middle category, while the largest eggs, labeled as jumbo eggs, will weigh approximately 30 ounces per dozen.

Chickens can lay eggs in varying colors including white, dark brown, light brown, and even shades of blue/green. Despite the color differences, there is no nutritional difference among eggs of different shell colors. One large egg contains six grams of high quality protein and all nine essential amino acids. Nearly half of this protein is found in the yolk, so eating the whole egg is important for receiving all of the nutrients. Additionally, the majority of an egg’s essential vitamins and minerals are in the yolk, including choline, selenium and the antioxidants, lutein and zeaxanthin.

Eggs are nutrient dense, and perfect for all meals of the day. Whether you prefer an omelet for breakfast, a fried egg sandwich for lunch, or a quiche for dinner, including eggs in your diet will help sustain your mental and physical energy all day long.

Abigail Martin

Abigail Martin is Wisconsin's 72nd Alice in Dairyland