Changzheng Guo, Shiyong Liao, Shourong Shi
The aim of this study was to evaluate the efficacy of a novel water-soluble corn protein (WCP) as a functional substitute for soybean meal (SBM) in broiler diets, using commercially mature cottonseed protein (CotP) as a reference alternative protein source. The WCP was produced from conventional corn steep liquor with an exceptionally high acid-soluble protein content (49.1%). A total of 504 one-day-old male Arbor Acres broilers were randomly assigned to three isonitrogenous and isocaloric dietary treatments: a basal diet control group (CON), a WCP group (5% of SBM replaced by WCP), and a CotP group (5% of SBM replaced by CotP). Over the 40-day experimental period, broilers fed the WCP diet had growth performance (final body weight, average daily gain, and feed-to-gain ratio), comparable to the CON group, and significantly outperformed the CotP group (P < 0.001). For carcass traits and meat quality, WCP inclusion significantly increased the dressing percentage (P = 0.042) and breast muscle yellowness (b* value, P = 0.004) compared to both CON and CotP groups. Serum biochemical analysis revealed that WCP supplementation significantly elevated the concentrations of total protein, globulin, and high-density lipoprotein (P < 0.05). Additionally, systemic antioxidant capacity was enhanced in the WCP group, evidenced by a significant increase in serum total superoxide dismutase activity (P = 0.049). These findings suggest that the bio-active peptides enriched in WCP during integrated processing provide physiological benefits beyond simple nitrogen supply. In conclusion, dietary replacement of 5% SBM with WCP maintains growth performance while enhancing slaughter yield and antioxidant capacity, demonstrating that WCP is an economically viable and functionally superior protein source for sustainable broiler production.