Veterinary Integrative Sciences

Comparison of growth promotion effects: Fermented non-medicinal parts of Scutellaria baicalensis vs. non-critical rare earth cerium oxide in yellow-feathered broilers

2025-07-29T17:40:26+07:00

This study investigated the effects of fermented Scutellaria baicalensis stem and leaves and Cerium Oxide (CeO₂) supplementation on the growth performance, slaughter performance, and immune function of yellow-feather broilers. The results demonstrated that the average daily feed intake (ADFI) was significantly higher (P < 0.05) in the treatment groups compared to the antibiotic-positive group. The group treated with 0.8% fermented Scutellaria baicalensis stems and leaves exhibited the high average daily weight gain and feed conversion ratio, surpassing the control group by 3.2% and 2.3%, respectively. Slaughter performance showed that the 0.8% Scutellaria baicalensis treatment group had greater chest depth, keel length, pelvic width, and tibia length than other groups. In contrast, the 500 mg CeO₂ treatment group exhibited the longest tibia length. Additionally, the slaughter rates of all treatment groups were significantly higher (P < 0.0001) than those of the control and antibiotic-positive groups. Immune function analysis revealed no significant differences (P > 0.05) in thymus and bursa indices; however, the thymus index was higher in groups with 0.8% Scutellaria baicalensis stem and leaves and CeO₂groups. Serum immunoglobulin analysis indicated that IgM and IgG levels did not significantly differ among groups, but CeO₂supplementation increased IgA levels, particularly in the 50 mg and 100 mg groups. These results illustrated that adding 0.8% fermented Scutellaria baicalensis stems and leaves to poultry feed effectively enhances improve the growth performance and carcass traits of yellow-feather broilers, and is a potential substitute for antibiotics in poultry production, compared to CeO₂ and Lincomycin hydrochloride.

Bacillus velezensis from the Muscovy Duck gut: A potential probiotic for controlling poultry pathogens

2025-11-19T08:37:22+07:00

Bacterial diseases and antimicrobial resistance threaten the poultry industry, necessitating antibiotic alternatives. Probiotics, especially Bacillus species, are a promising solution. This study explored the gut of the Muscovy duck (Cairina moschata (Linnaeus, 1758)) as an untapped source for novel probiotic candidates. The objectives were to isolate native Bacillus strains from Muscovy duck guts, identify the most promising candidate, and characterize its probiotic potential by assessing its resilience and antimicrobial activity against key poultry pathogens. A total of 40 bacterial strains were isolated from the gut contents of 50 Muscovy ducks using a heat-shock enrichment method. All isolates were screened in vitro for their tolerance to simulated gastrointestinal conditions (pH 2.0 and 0.3% bile salts). The antimicrobial activity of their cell-free supernatants was assessed against Escherichia coli, Salmonella enterica, and Staphylococcus aureus using the agar well diffusion method. The most potent isolate was definitively identified by 16S rRNA gene sequencing. Isolate BD31 demonstrated exceptional tolerance to both acidic and bile salt conditions. Furthermore, it exhibited potent, broad-spectrum antagonistic activity, producing significant inhibition zones against E. coli (12.5 mm), S. enterica (11.8 mm), and S. aureus (8.5 mm). Molecular analysis identified this superior isolate as Bacillus velezensis with 99.76% sequence identity to the type strain. The Muscovy duck gut is a valuable source for novel probiotics. Bacillus velezensis BD31 displays superior gastrointestinal tolerance and potent antimicrobial activity, positioning it as an excellent candidate for a direct-fed microbial to control poultry pathogens. In vivo validation is warranted.