Table 2.
Changes (%) LSM ± standard errors of the mean (s.e.) in pectoralis, supracoracoideus and lower leg muscle thickness (cumulative measurement of the M. gastrocnemius pars medialis, M. fibularis lateralis, and M. tibialis cranialis caput tibiale and femorale) as measured by ultrasound, and bodyweight in white- and brown-feathered hens two, four and six weeks after wing feather damage (unclipped, half-clipped and full-clipped). Within a given muscle group and certain week, LSM ± s.e. that do not share a letter superscript indicates that the percentage change from baseline/week 0 is significantly different between clipping treatments (p < 0.05). Values that are italics show a percentage of change that is significantly different from baseline.
| muscle | treatment | weeks since treatment |
||
|---|---|---|---|---|
| 2 weeks | 4 weeks | 6 weeks | ||
| white-feathered | ||||
| pectoralis | unclipped | 13.20 ± 3.09%A | 2.97 ± 3.44%A | 1.70 ± 2.06%A |
| half-clipped | 7.77 ± 3.34%A | −5.10 ± 3.61%B | −5.78 ± 2.32%B | |
| full-clipped | 7.24 ± 3.34%A | −4.86 ± 3.61%B | −6.01 ± 2.32%B | |
| supracoracoideus | unclipped | −1.36 ± 1.61%A | −2.34 ± 1.33%A | 2.51 ± 1.13%A |
| half-clipped | −1.91 ± 1.71%A | −2.78 ± 1.43%A,B | 2.14 ± 1.27%A | |
| full-clipped | −3.37 ± 1.71%A | −5.84 ± 1.43%B | 0.49 ± 1.27%A | |
| lower leg | unclipped | 7.79 ± 1.65%A | 5.88 ± 1.86%A | 9.04 ± 1.95%A |
| half-clipped | 5.30 ± 1.78%A | 5.63 ± 1.97%A | 6.44 ± 2.08%A | |
| full-clipped | 3.73 ± 1.78%A | 3.52 ± 1.97%A | 7.00 ± 2.08%A | |
| bodyweight | unclipped | 0.40 ± 1.12%A | 0.26 ± 1.27%A | 0.28 ± 1.36%A |
| half-clipped | −3.10 ± 1.16%B | −4.79 ± 1.33%B | −4.45 ± 1.43%B | |
| full-clipped | −4.86 ± 1.16%B | −6.28 ± 1.33%B | −6.37 ± 1.43%B | |
| brown-feathered | ||||
| pectoralis | unclipped | 18.63 ± 3.16%A | 13.15 ± 3.55%A | 5.99 ± 2.22%A |
| half-clipped | 9.85 ± 3.40%B | 5.13 ± 3.66%B | 1.85 ± 2.51%A | |
| full-clipped | 10.99 ± 3.48%A,B | 6.59 ± 3.71%A,B | 3.25 ± 2.60%A | |
| supracoracoideus | unclipped | −3.58 ± 1.64%A | −3.51 ± 1.39%A | 2.52 ± 1.22%A |
| half-clipped | −3.91 ± 1.73%A | −5.00 ± 1.45%A | −0.77 ± 1.38%A | |
| full-clipped | −4.94 ± 1.76%A | −4.02 ± 1.48%A | 0.60 ± 1.43%A | |
| lower leg | unclipped | 2.02 ± 1.69%A | 2.14 ± 1.93%A | −1.03 ± 2.03%A |
| half-clipped | 1.84 ± 1.85%A | 1.90 ± 2.03%A | 2.53 ± 2.24%A | |
| full-clipped | 2.57 ± 1.86%A | 1.60 ± 2.04%A | 3.67 ± 2.24%A | |
| bodyweight | unclipped | 1.00 ± 1.13%A | 1.90 ± 1.30%A | 2.93 ± 1.40%A |
| half-clipped | −0.77 ± 1.17%A | −1.90 ± 1.34%A | −1.52 ± 1.49%A | |
| full-clipped | −0.32 ± 1.19%A | −0.94 ± 1.36%A | 0.21 ± 1.52%A | |