2023 Volume 15 Issue 1 Pages 4-9
This study investigated the effects of feeding self-sufficient feed (dried bonito extract residue [DBER], rice screenings, and rice bran) on meat and egg productivity, as well as DHA content in the meat and egg yolk of the cross-bred Satsuma Black Aigamo duck (Aigamo duck) under free-ranging conditions.
In experiment 1, 12 Aigamo ducks (♂4: ♀8, 1 week old) were assigned to one of two treatments. The control group was provided with a commercially available diet (crude protein, 15.2%; metabolizable energy, 2,800kcal/kg) and the experimental group was given a self-sufficient diet (40% DBER, 40% rice screenings, and 20% rice bran) (crude protein, 26.9％). The feed conversion ratios of the control and experimental groups from 1 to 15 weeks of age were 5.4 and 4.9, respectively. The body weight and carcass characteristics at 15 weeks of age were not different between the two groups. The docosahexaenoic acid (DHA) content of the breast meat of the experimental group was 294mg/100g, but DHA was not detected in the control group.
In experiment 2, 26 Aigamo ducks (♂6: ♀20, 26 weeks old) were assigned to one of two treatments. The control group was provided with a commercially available diet (crude protein, 15%; metabolizable energy, 2,800kcal/kg) and the experimental group was given a self-sufficient diet (50% DBER, 30% rice screenings, 10% rice bran, and 10% oyster shell) (crude protein, 29.7％). The feed conversion ratios of the control and experimental groups from 26 to 51 weeks of age were 3.4 and 3.1, respectively. Egg weight was significantly greater in the experimental group than the control group (P<0.01). A significant difference was found in the egg production rate between the control and experimental groups (control group, 80.3%; experimental group, 83.6%; P<0.01). However, the two groups showed no significant differences in hatchability. The DHA content of the egg yolk was significantly higher in the experimental group than the control group (P<0.01).
The results indicated that DBER, rice screenings, and rice bran may be a promising self-sufficient feed for Aigamo ducks and it may improve the quality of their products.
