Effects of dietary soy sauce residue on growth performance, organ development, plasma biochemical parameters, and meat quality of Pekin ducks.

Abstract

Soy sauce residue (SSR), a by-product of soy sauce production industry that is rich in protein and amino acids, was investigated for its effects on the growth and organ development, plasma biochemical parameters, meat quality, and breast muscle metabolites of Pekin ducks. A total of 280 healthy male 1-day-old ducks were randomly divided into 5 groups (7 replicates, 8 birds/replicate). The ducks were fed a corn-soybean meal supplemented with varying levels of SSR (0%, 2%, 4%, 6%, and 8%). The study found that the addition of 4% SSR had no significant effect on growth performance, organ development, and meat quality of Pekin ducks (P > 0.05). In terms of plasma biochemistry parameters, the contents of ALT, AST, TP, ALB, DBIL, CK, CHO, and HDLC in the 6% and 8% SSR groups were significantly decreased (P < 0.05). CK showed a liner decrease with the increasing SSR level (P < 0.05). Additionally, the contents of proline, histidine, aspartic and acetic acid in the breast muscle of the 8% SSR group were significantly decreased (P < 0.05). Analysis of breast muscle metabolites revealed that there was a total of 71 differential metabolites between the control and 8% SSR groups, which were associated with anti-inflammatory and antioxidant functions. In summary, SSR may serve as a novel feed ingredient in meat duck production, and an inclusion level of 4% appears to be safer in this experiment.