Effect of water depth on pool choice and bathing behaviour in commercial Pekin ducks

Pekin ducks (Anas platyrhynchos domestica) are raised for meat, often in indoor intensive systems. Research into the welfare of intensively reared clucks makes clear the importance of access to bathing water. Most researchers agree that bathing behaviours such as preening are important; however, the welfare implications of swimming are not so clear. A choice test was therefore designed to compare three depths of water: 10 cm, where ducks could stand but not swim; 20 cm, where ducks could stand and swim; and 30 cm, where ducks could swim but not stand. Ducks were housed in groups of four and each group had access to a shallow pool (10 cm), a deeper pool (either 20 or 30 cm) and two turkey bell drinkers which were added just as sources of clean drinking water. Observations were made between 29 and 48 days post-hatch. No difference was found between the usage of 10 and 20 cm deep pools, but ducks chose to use the 10 cm pools more than the 30 cm pools. This is a useful indication of duck preferences for water depth, but not a definitive measure because observations of bathing behaviour suggested that pools of different depths were used in different ways (30 cm pools were more suitable for swimming, but more dabbling was performed in the 10 cm pools than in deeper pools) and because not all groups of ducks made the same choices. Age had very little effect on bathing behaviour. Water cleanliness was also considered in the analysis: when the water was dirty, ducks spent less time inside the pools, spent less time sitting during bathing bouts and drank more from the bell drinkers. These results indicate that water depth and cleanliness have an impact on duck bathing behaviour. (C) 2012 Elsevier B.V. All rights reserved.