|Cheng, Heng Wei|
Submitted to: Applied Animal Behaviour Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/9/2006
Publication Date: 7/11/2007
Citation: Gustafson, L.A., Cheng, H., Garner, J.P., Pajor, E.A., Mench, J.A. 2007. Effects of bill-trimming Muscovy ducks on behavior, body weight gain, and bill morphopathology. Applied Animal Behavior Science. 103:59-74. Interpretive Summary: Beak trimming is a routine husbandry practice used in the poultry industry to prevent feather pecking and cannibalism. It typically involves the removal of 1/3 to 1/2 of the upper and lower beak using a heated blade that cuts and cauterizes the beak tissue. The results from this study showed that current bill-trimming methods cause acute, but not chronic, pain in Muscovy ducks. The findings could be adapted by producers and other scientists to develop animal well-being standards and guidelines for management practices.
Technical Abstract: In commercial production facilities, ducks are often bill-trimmed to prevent feather pecking and cannibalism. Beak-trimming of chickens and turkeys has been criticized because of its potential to cause acute and chronic pain, but little is known about the effects of bill-trimming on the welfare of ducks. We conducted a study to determine the effects of a commercial bill-trimming method, cutting without cautery, on the behavior and bill morphopathology of ducks. Muscovy ducks were housed in 12 pens each containing 16 ducks (8 males and 8 females). Half of the ducks were trimmed (TRIM) using scissors at 20 days post-hatch, while the rest were sham-trimmed (NOTRIM). The average length removed from the upper bill was 0.51 cm, or 21.1% of the bill length from nares to tip. The behavior of all ducks was recorded during the first week post-trim using scan sampling. In addition, two ducks/sex/pen were randomly selected as focal birds, and observed using 15-min focal samples during the morning (0900-1100) and afternoon (1200-1500) for 12 weeks. Ducks were weighed weekly. Behavioral and body weight data were analyzed using the General Linear Model. At 12 weeks of age, the bills of the male focal ducks were collected and subjected to gross and morphopathological analysis. In the days immediately post-trim, NOTRIM ducks spent significantly (p < 0.0001) more time engaging in bill-related behaviors (preening, feeding, drinking, exploratory pecking) and less time resting than TRIM. These differences disappeared by one week post-trim. At one week post-trim the TRIM ducks weighed less (p = 0.0064) than NOTRIM, but there was no treatment difference in weights by 2 weeks post-trim. By six weeks post trim the upper bill of TRIM was only 11.9% shorter than the lower bill. There was evidence of feather pecking in the TRIM pens, but feather pecking and skin damage were more extensive in the NOTRIM pens. The TRIM bill stumps were covered with epithelium, lacked blood vessels and showed evidence of scarring, but there were no neuromas. These results are consistent with this bill-trimming method causing acute, but not chronic, pain in Muscovy ducks.