|Cheng, Heng wei|
Submitted to: International Society of Applied Ethology
Publication Type: Abstract only
Publication Acceptance Date: 4/6/2005
Publication Date: 7/31/2005
Citation: Gustafson, L., Cheng, H., Garner, J.P., Pajor, E.A., Mench, J.A. 2005. Effects of bill-trimming on the welfare of ducks. International Society of Applied Ethology. p. 56. Interpretive Summary:
Technical Abstract: Ducks on commercial farms are routinely bill-trimmed to prevent feather pecking and cannibalism. We evaluated the effects of bill-trimming on the welfare of Muscovy (MUS) and Pekin (PEK) ducks. In conformance with commercial practice, MUS (N = 96) were trimmed at 3 wk of age by cutting without cautery, while PEK (N = 192) were trimmed at hatch either by cutting with cautery or by tip-searing. Time budgets were assessed using focal and scan samples taken from the day after trimming until processing age. Data were analyzed using the GLM. In the first week post-trim, untrimmed (NOTRIM) MUS and PEK spent an average of 33% and 26%, respectively, of their time performing bill-related behaviors. Trimmed MUS and PEK performed these behaviors significantly (p < 0.001) less often (5% and 11% of time for MUS and PEK, respectively), and also rested significantly more (MUS = 91%, PEK = 88%) than NOTRIM ducks (MUS = 60%, PEK = 74%). By 2 weeks post trimming there were no longer behavioral differences between treatments. Trimmed MUS gained significantly (F 1,141 = 30.73, p<0.0001) less weight (4% less) than NOTRIM MUS during the week following trimming, although this difference disappeared by wk 2. There was no treatment effect on body weights of PEK (p>.10). At processing age, there were more ducks with moderate to severe feather damage or tissue injury in NOTRIM (PEK = 58%; MUS = 28%) than trimmed pens (PEK = 9%, MUS = 5%). Morphological analysis of the bills revealed evidence of scarring at the site of trimming. The particularly thick scar tissue in MUS had apparently impeded nerve and blood vessel re-growth into the bill. However, there was no evidence of neuroma formation in any trimmed group. These results are consistent with bill-trimming causing acute, but not chronic, pain in ducks.