Generally, in Indonesia the duck is reared for producing egg rather than flesh. More than 19 percent of egg demand is fulfilled by duck’s egg, but the demand for flesh is still low, that is 0.94 percent from national demand. Feeding management in poultry production is very important, because approximately 70 percent of production cost is devoted for feeding. The experiment was aimed to study the effect of avilamisina on growth, percentage of edible and non-edible portion of Mandalung duck at 4 and 10week-slaughter age. This experiment used 138Mandalung day-old duck. There . were 3 groups as replicate that consisted of 23 ducks without sex differentiation. Groups were divided basedon the treatment; with and without addition of avilamisina. The data were analyzed and tested by using t student test. The result showed that avilasimina gave a response on the growth of Mandalung, meanwhile the responsewas very significant on edible portion, e. g. heart at 4 week-slaughter age and gizzard at 10 week-slaughter age. Non-edible portions were very significant on blood, feather at 4 week-slaughter age and also head and intestine at 10 weeks laughter age. Oleh Matitaputty Procula Rodlof dan Sari M. Agria (Jurnal Penelitian dan Kajian ilmu-ilmu Pertanian) – Indonesia tahun 2007. vol. 3(2)p. 19 – 24