Table 2 Definitions of facial action units (FAU) of the calf grimace scale in both front and side views.
From: Development of the calf grimace scale for pain and stress assessment in castrated Angus beef calves
FAU | Definition | ||
|---|---|---|---|
Score zero | Score one | Score two | |
Ear position | Both ears forward (both angles): both ears (for front) or one ear (for side) are directed rostrally, the ear pinna can be (or cannot for side images) completely seen, and the angle between the eye commissure, the base of the ear and the tilt of the ear is 90 degrees or less | One ear forward, one backward (front angle only): use the previous and following definitions for forward ear and backward ear, respectively. For side images, no score 1 is assessed, as only one ear is reliable visible from this view. It is scored zero if the ear is forward and 2 if it is backward | Both ears backward (both angles): both ears (for front) or one ear (for side) are directed caudally, the ear pinna moderately or completely cannot be seen, and the angle between the eye commissure, the base of the ear and the tilt of the ear is more than 90 degrees |
Orbital tightening | Eyes completely open: eyelids are not in contact with each other, appear as a curve shape, and the entire eyeball is completely visible | Eyes moderately closed: eyelids are not in contact with each other, upper eyelid appears as a straight line, entire eyeball is not completely visible | Eyes obviously closed: eyelids are in contact with each other, the entire eyeball is not visible |
Tension above the eye | Not present: no prominent line (s) or curve shape (for side images) appear above the eye area due to the contraction of muscles above the eye | Moderately present: a slightly visible line (s) or curve shape (for side images) appear above the eye area due to contraction of the muscles above the eye | Obviously present: prominent line or lines or curve shape (for side images) appear above the eye area due to the contraction of muscles above the eye |
Nostril dilation | Not strained: nostrils are in a normal relaxing shape with cashew/elliptical shape | Moderately strained: nostril orifices increased in size and appeared nearly triangular or enlarged cashew shape | Obviously strained: nostrils orifices are obviously open and appear nearly circular or heart shape |
Strained chewing muscle | Not present: the skin over the cheek area appears relaxed and there are no lines or grooves present | Moderately present: the skin over the cheek area appears moderately strained and contraction of the cheek muscles causes appearance of slightly visible lines or shallow grooves | Obviously present: the skin over the cheek area appears obviously strained and contraction of the cheek muscles causes appearance of clearly visible lines or deep grooves |
Mouth Opening | Completely closed: upper and lower jaws are in contact with each other | Moderately open: upper and lower jaws are not in contact with each other, the tongue may appear. The mouth opens at ~ 20 degrees or less | Obviously open: upper and lower jaws are not in contact with each other, the tongue may appear. The mouth opens at more than 20 degrees |
