Microecological preparations (including probiotics, prebiotics, synbiotics) and phytobiotics or phytochemicals are promising but diverse additives that can improve the health and performance of poultry (1). While the beneficial effects of many of the microecological preparations have been well documented, there is a general perception that these products lack consistency (2, 3). In addition, the combinations of microecological preparations and phytobiotics or phytochemicals may prove more beneficial than using them alone (4). For example, prebiotics may boost probiotic strain development and cloning, combination of probiotics and phytogenic feed additives can have beneficial synergistic effects on the gut microbiota in young chickens (4, 5).
Phytogenic feed additives (PFAs) are a wide range of bioactive compounds, which have potential positive effects on poultry health and productivity (4, 6). The antioxidant components of PFAs belong to different chemical categories and can be recycled and obtained as plant extracts, essential oils or resins (7). Panax ginseng contains a variety of active ingredients, such as polysaccharides, saponins, volatile oils, alkaloids, amino acids, and other chemical components, and most of the medicinal properties of ginseng are attributed to polysaccharides and ginsenosides (8–10). Ginseng polysaccharide (Gps) has been reported to have the function of enhancing immune activity (9, 11). Moreover, oral supplementation of Gps dosages (100 mg/kg, 200 mg/kg, and 400 mg/kg) eliminated weight loss in chickens following vaccination (H5N1) (12). Gps also altered the composition and diversity of gut microbiota in chickens (13) and mice (14) with antibiotic-associated diarrhea, restored the gut microbiota, balanced metabolic processes, and promoted the recovery of the mucosa.
In poultry production systems, probiotics are used to improve feed efficiency and growth performance and reduce foodborne pathogens (15). There are 12 strains approved in China that can be used to directly feed animals, including Lactobacillus plantarum, Bacillus subtilis, Saccharomyces cerevisiae, Enterococcus faecium, etc. Microbial fermented feed (MF) has gained significant popularity within the chicken industry due to its numerous benefits (16, 17). The process of fermentation has been found to enhance the crude protein content, while simultaneously reducing the levels of crude fiber and anti-nutritional factors present in the feed (18). These anti-nutritional factors include protease inhibitors, soybean protein, oligosaccharides in soybean meal, non-starch polysaccharides in corn, and phytic acid in bran. Consequently, the incorporation of fermented feed has been observed to positively impact the overall performance of chickens. Research reports that adding 7.5% fermented feed to the basal diet improves the growth performance, antioxidant capacity and immune function of laying hens (19). Feeding lactic acid bacteria fermented feed (supplement with lactic acid (160–250 mmol/kg feed) and acetic acid (20–30 mmol/kg feed)) can improve egg weight, shell weight, and shell hardness in laying hens (20). Furthermore, providing a fermented diet has also been demonstrated to improve immune responses, antioxidant capacity, intestinal digestive function, and morphology, as well as the gut microbial ecosystem of broilers (E. coli and Salmonella spp. decreased linearly with probiotic fermented feed level) (21–23). To date, the predominant focus of scholarly inquiry has been on the utilization of fermented feed or microorganisms as supplementary agents, leaving uncertain the viability of substituting conventional feed entirely with fermented feed.
The Xuefeng black-bone chicken, which originated in Hongjiang City, Huaihua City, and Hunan Province, China. It is a kind of meat and egg chicken, breed known for its high-quality meat.It has been officially recognized and included in the National Livestock and Poultry Genetic Resources Directory of China (13, 24, 25). However, the Xuefeng black-bone chickens face challenges such as low slaughter weight, extended feeding cycle, and low feed conversion ratio (FCR), all of which significantly impact their economic profitability.
This study primarily investigates the potential synergistic effects of combining MF and GPS in promoting growth and reducing inflammation. Additionally, it explores the viability of exclusively utilizing fermented feed for complete feeding.