The age × floor interaction had an effect when evaluating feather cleanliness (Table 4). A larger percentage of 7-d-old ducks scored 0 on litter compared with slats (P < 0.01). However, the proportion of 0 scores was reversed by d 32, with a greater proportion of ducks on slats than ducks on litter flooring scoring 0 (P < 0.01). Differences also existed between locations with both A and B different from location C for all duck scores (P < 0.04, Table 5).