Dang Thi My Tu et al., 2012. Livest. Res. Rural Dev., 24 (4): 72

The experiment was done with 72 local Muscovy ducks fed the experimental diets over a period of 84 days. Measurement of coefficients of apparent digestibility was carried out over the period 70 to 75 days; growth performance was measured over the whole period of 56 days (8 weeks). The ducks were bought at 1-day of age from smallholder breeding flocks in Cantho city and fed a commercial diet from 1 to 28 days of age. The treatments were: CTL, a basal control diet including rice bran with soybean meal; HPDW, rice bran with high protein duckweed; LPDW, rice bran with low protein duckweed. The three dietary treatments contained the same level of crude protein of 15% in DM. A premix (vitamins and minerals) was supplied at 2% of the CTL diet. In treatments HPDW and LPDW it was assumed that the duckweed would provide the necessary vitamins and minerals. The HPDW was cultivated in ponds supplied with biodigester effluent according to the optimum treatment in the earlier experiment (paper 1). For LPDW, the duckweed was collected from natural ponds of local farmers. Final live weight and daily live weight gain were highest when the supplementary protein was from high protein duckweed and lowest when low protein duckweed was the supplement. The growth rate on rice bran supplemented with soybean meal was lower than for rice bran supplemented with high protein duckweed. There were few differences in carcass traits when the ducks were slaughtered, except for a more attractive skin color for the ducks fed duckweed. The heavier gizzard in ducks fed duckweed probably reflected the higher fiber content of these diets. N retention was highest on the high protein duckweed diets and lowest for the low protein duckweed diets. The better economic results on the high duckweed diet resulted from lower feed costs and higher weight at slaughter.