Later synthetic milk stage piglets (after 35 days of age, 10-30 kg body weight) were fed scallop mantle enzyme degradation product (SMDP) to examine the effect of the supplement on growth, carcass characteristics, and meat quality. Thirty-five day-old, three-way crossbred (LWD), castrated pigs weaned at 21 days of age and acclimatized for 2 weeks were divided into two groups: a control group fed a commercial diet of later synthetic milk stage, and an experimental group fed the same diet but supplemented with 5% DM SMDP on a dry basis. The pigs were then fed a commercial feed for the growing (30-70 kg body weight) and finishing (≥70 kg) stages. Pigs were reared to a body weight of 115 kg, fasted for at least 12 h, and slaughtered according to conventional methods. During the later synthetic milk stage, daily weight gain (ADG) tended to be higher in the experimental than the control groups (P<0.1). As no differences in feed intake were observed between the two groups, the feed conversion ratio was significantly lower in the experimental group (P<0.05). Although the ADG was similar during the growing stage, it tended to be higher during the finishing stage in the experimental group (P<0.1); the experimental group tended to have a slightly higher ADG during the fattening period (P<0.1) and tended to reach 115 kg at a slightly younger age (P<0.1). Feed intake and feed conversion ratio were similar between the two groups in the growing and finishing stages. Carcass and back and loin length I tended to be longer in the experimental than in the control groups (P<0.1). Back and loin length II were longer in the experimental than in the control groups (P<0.05). Cooking loss and shear force were similar in the two groups. Feeding SMDP may enhance body weight gain during the later synthetic milk and the finishing stage and lengthen carcasses.