Influence of Mushroom Polysaccharide, Nano-Copper, Copper Loaded Chitosan, and Lysozyme on Intestinal Barrier and Immunity of LPS-mediated Yellow-Feathered Chickens

SIMPLE SUMMARY: Recently, there has been an increasing worldwide interest in limiting or banning the use of synthesized antibiotic growth promoters used in animal production, so as to avoid the development of the drug resistance of human pathogens. This is accelerating the efforts of scientists to present new, natural and safe antibiotic alternatives that are adequate for animal and poultry production. This study contributes by evaluating some potent antibiotic alternatives in growing yellow feathered chicks, including mushroom polysaccharides, nano-copper, copper loaded chitosan, and lysozyme, versus a common antibiotic (Aureomycin). The dietary addition of the tested substances has demonstrated several beneficial effects, particularly in the case of polysaccharides (100 mg/kg) and lysozyme (500 mg/kg), on jejunal barrier, and immunity of yellow-feathered chicks aged 4–24 days, with comparable effects to the antibiotic treatment. ABSTRACT: This study investigated the influence of dietary supplementation with some antibiotic alternatives on growth performance, intestinal barrier, and immunity of lipopolysaccharide (LPS) challenged chicks. Wenshi females, aged 4 days, were allocated randomly into eight groups, each with six replicates of 20 birds (n = 120/treatment), which received a basal diet supplemented with 0 (control), 0 (LPS), 200 mg/kg aureomycin, 50 mg/kg mushroom polysaccharide, 100 mg/kg mushroom polysaccharide, 500 mg/kg nano-copper, 300 mg/kg copper loaded chitosan, and 500 mg/kg lysozyme for 21 days. On day 18 and 20, the control birds were injected with 0.5 mL saline solution, the other treatments were injected with 0.5 mL saline containing 500 µg LPS/kg body weight (BW). The results indicated that LPS treatment reduced the BW, average daily gain (ADG), and daily feed intake (ADFI) than the controls (p < 0.05), and the antibiotic and the tested alternatives could not retrieve the normal BW, ADG, and ADFI. The tested additives reduced several negative effects of LPS; they reduced diamine oxidase activity and inflammatory mediators in plasma, jejunal mucosa, spleen and thymus, increased content of immunoglobulin in plasma and jejunal mucosa, and decreased gene expression of inducible nitric oxide synthase and Cyclooxygenase 2 in jejunal mucosa.