Two hundred and fifty-six healthy
Shaoxing 7-wk old growing layer ducks were selected and randomly allocated to 1 of 4 dietary treatments based on corn and soybean
meal and containing 0, 3, 6, and 9% of alfalfa meal for 8 wks. Each treatment consisted of 4 replicates of 16 ducks each. Briefly, birds
were raised in separate compartments, and each compartment consisted of three parts: indoor floor house, adjacent open area and a
connecting water area.