The Effects of Fermented Feed on the Growth Performance, Antioxidant Activity, Immune Function, Intestinal Digestive Enzyme Activity, Morphology, and Microflora of Yellow-Feather Chickens

SIMPLE SUMMARY: The chicken digestive system is not fully developed, and the feed type and shape have essential effects on it. The growth performance and health status would be affected in various ways during this stage. Immune function and antioxidant capacity can explain this mechanism at the endocrine level. Fermented feed is a new feed type that saves food crops, has the potential to promote growth and development, improve animal welfare and help them stay healthy, and is beneficial to human food safety. We studied the effects of fermented feed on the growth performance, antioxidant activity, immune function, intestinal digestive enzyme activity, morphology, and microflora of yellow-feather chickens. The results showed that adding fermented feed increased the digestive enzyme activity, ameliorated intestinal morphology, cecal microflora, beneficial bacteria richness, immune function, and antioxidational ability of chickens without effects on growth performance. In conclusion, the fermented feed added to the chickens’ diets improved the growth performance, antioxidant activity, immune function, intestinal digestive enzyme activity, morphology, and microflora of yellow-feather chickens. This study offers a more theoretical basis for exploiting and utilizing new fermented feed resources and the sustainable and healthy development of poultry farming. ABSTRACT: This experiment was conducted to investigate the effects of fermented feed on growth performance, antioxidant activity, immune function, intestinal digestive enzyme activity, morphology, and microflora of yellow-feather chickens. A total of 240 one-day-old female yellow-feathered (Hexi dwarf) chickens were randomly divided into two treatment groups, with six replicates per group and 20 chickens per replicate. The control group (CK) received a basal diet, whereas the experimental group was fed a basal diet of +2.00% fermented feed (FJ). The trial lasted for 22 days. Compared with the CK, (1) the growth performance was not affected (p > 0.05); (2) immunoglobin a, immunoglobin g, immunoglobin m, interleukin-1β, and interleukin-6 were affected (p < 0.05); (3) liver superoxide dismutase, glutathione peroxidase, and catalase were higher (p < 0.05); (4) trypsin activity in the duodenum and cecal Shannon index were increased (p < 0.05); (5) the relative abundance of Actinobacteriota in cecum was increased (p < 0.05); (6) the abundance of dominant microflora of Bacteroides as well as Clostridia UCG-014_norank were increased (p < 0.05). In summary, the fermented feed improved the growth performance, antioxidant activity, immune function, intestinal digestive enzyme activity, morphology, and microflora of yellow-feather chickens.