Evaluation of natural anti-stress oral liquids on immune regulation and growth promotion in three-yellow chicken.

This study aimed to evaluate the efficacy of a natural anti-stress oral liquid, composed of 16 Chinese medicinal herbs, as a green feed additive for broilers. A total of 180 one-day-old three-yellow chicks were randomly assigned to three groups: a control group (0 g/L) and two treatment groups receiving the oral liquid at 0.5 g/L and 1.0 g/L via drinking water for 49 days. The results demonstrated that the 1.0 g/L dosage significantly enhanced growth performance, increasing the final body weight by 10.6% (P < 0.026) and the slaughter rate by 2.8% (P < 0.05). Concurrently, this dosage markedly improved meat quality, evidenced by a 25.4% reduction in shear force (P < 0.024), a significant increase in intramuscular fat (P < 0.042), and elevated levels of total essential amino acids (P < 0.001) and umami amino acids (P < 0.05). Furthermore, the 1.0 g/L oral liquid bolstered immune function by significantly increasing serum IgA and IgG levels (P < 0.05) and immune organ indices (P < 0.05), while also enhancing antioxidant capacity through elevated serum T-AOC, SOD, and GSH activities (P < 0.05). Analysis of cecal microbiota revealed that the treatment enriched beneficial bacteria such as Lactobacillus and Faecalibacterium (P < 0.05). Acute toxicity tests confirmed the formulation's high safety. In conclusion, the natural anti-stress oral liquid, particularly at 1.0 g/L, effectively promotes growth, enhances immunity, and improves meat quality in three-yellow chickens, proving to be a safe and promising additive for healthy poultry farming.