Poultry Judging Practice Test

How long does an egg remain in the Isthmus?

1. 30 minutes

2. 1 hour

3. 1.25 hours

4. 1.5 hours

The correct answer is: 1.25 hours

In poultry anatomy, the Isthmus is a specific segment of the hen's oviduct where the egg undergoes crucial development. During its time in the Isthmus, the egg is primarily formed into what will become the egg white, or albumen, and the inner membranes are created. This process generally takes about 1.25 hours. Understanding the timing within each part of the oviduct is key for grasping how eggs are formed and the importance of each segment in ensuring the final quality of the egg. The Isthmus is positioned between the infundibulum, where fertilization occurs, and the uterus (shell gland), where the eggshell forms. The precise time an egg spends in the Isthmus significantly contributes to the characteristics of the egg, including its size and quality. Therefore, knowing that it remains there for approximately 1.25 hours reinforces the biological processes involved in egg production.