Here we have a photo showing a 45° angle applied to the back end of a hen with the correct tail set.
The ACBA (Ayam Cemani Breeders Association) SOP (Standard of Perfection) calls for a 45° tail angle. While this may seem like just another “check” on the list, there’s actually a very important reason behind it.
Tail set is not merely about aesthetics - it plays a huge role in overall health, muscle structure, and balance depending on the bird’s functionality and purpose.
Heavier breeds tend to have a lower tail set, often paired with a broader chest and deeper muscle development. However, excessively low tail sets can create imbalance, potentially leading to structural issues like knock-knees or splayed legs.
Higher tail sets are typically seen in more upright birds and can result in a leaner build with a narrower breast.
Chickens with a 45° tail angle tend to have better pelvic muscle development, creating a more balanced frame with even muscle distribution. This balance can also support improved egg production and reproductive health.
Birds with proper tail angles are generally more mobile and comfortable, allowing them to engage in natural behaviors like foraging and dust bathing - both essential for strong muscle development and overall well-being.
Now, an improper tail set is not the end-all. As long as the bird does not exhibit a squirrel tail (a disqualifying trait) or other non-negotiable faults, it can still be worked with in a breeding program.
A squirrel tail is identified when the tail is carried too far forward - at or ahead of vertical (90° or more), often curving over the back toward the head. This disrupts balance and is considered a serious structural fault.
Instead of culling progress, pair birds thoughtfully - select mates that complement one another to help improve tail set in future generations.