Effects of angel wings on morphological and histological characteristics of White Roman geese

Abstract

This study aims to determine the effects of normal and angel wing on morphological and histological characteristics of white Roman geese. Angel wing is a torsion of a wing at the carpometacarpus all the way down to the end, stretching outward away from the body lateral. In this study, 30 geese were raised for observing the whole appearance, including stretched wings and morphologies of defeathered wings at 14 wk old. A group of 30 goslings was raised to observe the feature of conformation development of wing bones from 4 to 8 wk old by X-ray photography. The results show that normal wing on angles of the metacarpals and radioulnar bones has a trend greater than the angel wing group (P = 0.927) at the age of 10 wk. According to 64-slice images of computerized tomography scanner on a group of 10-wk-old geese, the interstice at the carpus joint of the angel wing was larger than that of the normal wing. The slight to moderate dilated space of the carpometacarpal joint was found in the angel wing group. In conclusion, the angel wing is torqued outward away from the body laterals at the carpometacarpus and has a slight to moderate dilated space in the carpometacarpal joint. The normal wing geese exhibited an angel that is 9.24% greater than those of angel wing geese at the age of 14 wk (130 vs. 118.5°).

Keywords: angel wing; histological; morphology; white Roman geese.

Figure 1

The whole appearances (A), stretched wing (B), and morphologies of defeathered wing (C) of normal wing (Left picture) and angel wing (D, E, F) (Right picture) at 14-wk-old in white Roman geese. In (C), the angle of the freely stretched plane of the wing between mid-section (II) and tip (I) in normal wing was larger than that in angel wing.

Figure 2

The X-ray photographs of normal wing (A) and angel (B) wing in white Roman geese were taken at the ages of 4 wk (A-4; B-4), 6 wk (A-6; B-6), and 8 wk (A-8; B-8). The arrow was pointing toward the radial carpal at the joint of the carpus. When the geese were at the age of 4 and 6 wk, no apparent abnormality showed up at the joint of the carpus in consistent with the normal external appearance of the wing. However, the interstice at the joint of the carpus at the age of 8 wk in angel wing was larger than that in normal wing implying that the displaced carpus was torqued by presumably abnormal or displaced ligament around the bone. The red line indicated the angle between the metacarpals and radioulnar bones. It was obtained by using a protractor to measure the included angle between the 2 parallel lines, which were the midline of radius and ulna, and the midline of carpometacarpus.

Figure 3

The X-ray photographs of normal wing and angel wing in white Roman geese were taken at the ages of 8 wk (A, B), 10 wk (C, D), 12 wk (E, F), and 14 wk (G, H). The arrow was pointing toward the radial carpal at the joint of the carpus. The interstice at the joint of the carpus at the age of 8, 10, 12, and 14 wk in angel wing was larger than that in normal wing implying that the displaced carpus was torqued by presumably abnormal or displaced ligament around the bone. The red line indicated the angle between the metacarpals and radioulnar bones. It was obtained by using a protractor to measure the included angle between the 2 parallel lines, which were the midline of radius and ulna, and the midline of carpometacarpus.

Figure 4

The joints of metacarpal bone of normal wing (A, C) and angel wing (B, D) with 64-slice computerized tomography scanner at 10 wk old in white Roman geese.

Figure 5

Morphology of wings in normal and angel wing geese. Section A was selected from radio carpal (A) and carpometacarpal joints to be section B (B) for normal wing (C) and angel wing (D), respectively.

Figure 6

Histological findings of wings in normal and angel wing geese. Normal space of radio carpal joint in the right and left wing (A and B, arrow) and angel wing (C and D., arrow) geese. Carpometacarpal joins with tight joint presented in the right and left wing (E and F, open arrow) in a normal goose; however, slight to moderate dilated space of carpometacarpal joint was found in the right and left wing (G and H, arrow) in angel wing goose, indicating that no difference in the radio carpal joints between normal and angel wing geese, but slight to moderate dilated space happened in the carpometacarpal joint of the angel wing goose. HE stain, 20×.