2. A total of 480, one-day-old male Lingnan yellow-feathered broilers were divided into four treatment groups with six replicates, each containing 20 broiler chickens. Broilers in the four groups were offered either a basal diet (without antibiotics) or test diets containing 5, 10 and 15% of PFF respectively. The experiment lasted for eight weeks. 3. Birds fed the 10% PFF diet exhibited increased (P<0.05) average daily gain (ADG) on d 28 and 56, body weight (BW) on d 56, total tract apparent digestibility (TTAD) of dry matter (DM), crude protein (CP) and gross energy (GE). Feeding diets supplemented with 10% PFF increased (P<0.05) digestive activity and gut development in duodenum and jejunum. Supplementation with 10% or 15% PFF significantly increased (P<0.05) the caecal populations of Lactobacilli and Bifidobacteria spp. and decreased (P<0.05) caecal E. coli and Salmonella spp. on d 28 and 56. 4. The ADG and BW on d 56, protease activity in duodenum on d 56 and jejunum on d 28 and 56, villus height and villi absorptive area in duodenum and jejunum and caecal Bifidobacteria spp. showed a quadratic (P<0.05) dose response as supplemental PFF level increased. The TTAD of DM and CP and caecal Lactobacilli spp. increased linearly with PFF level. The caecal populations of E. coli and Salmonella spp. decreased linearly with PFF level. 5. In conclusion, addition of PFF in broiler diets had the potential to improve production performance, nutrient utilisation, intestinal digestive function and caecal microflora in yellow broiler chickens raised at high altitude.

Brucellosis, caused by Brucella species, remains a significant zoonotic disease affecting both human and animal health worldwide. Among the outer membrane proteins (Omps) of Brucella, Omp16 has emerged as a key immunogenic target with potential applications in vaccine development and diagnostics. Omp16, a lipidated peptidoglycan-associated lipoprotein, stimulates a strong proinflammatory response and is essential for maintaining the bacterial outer membrane integrity and facilitating host cell invasion. This review examines the immunogenic properties of Omp16, its role in Brucella pathogenesis, and its potential as a candidate for vaccine development. We discuss how Omp16-based vaccines, including recombinant proteins, outer membrane vesicles, and viral vector vaccines, have shown promise in providing protection against Brucella infections in animal models. Additionally, Omp16’s utility in diagnostic applications, particularly in enzyme-linked immunosorbent assays (ELISA), offers a reliable method for detecting brucellosis in both humans and animals. Overall, Omp16 represents a crucial antigen with significant potential for advancing both the diagnosis and prevention of brucellosis, offering insights into the next generation of brucellosis vaccines and diagnostic tools.

Calf diarrhea is a prevalent and significant health issue in dairy farming, severely impacting feed intake, weight gain, and survival rates in young calves. This study aimed to investigate the microbial composition and antibiotic resistance profiles of diarrheic calves to provide insights into the epidemiology and management of the condition. The prevalence of diarrhea in 1685 calves was analyzed. Rectal fecal samples were collected from five healthy and five diarrheic Holstein calves on a large dairy farm in Shaanxi Province, China. High-throughput 16S-rRNA sequencing and PCR were utilized for microbial and resistance gene analysis. In 2023, the overall diarrhea rate among 1685 calves was 9.08%, with a significantly higher diarrhea rate during the suckling period (8.13%) compared to the post-weaning period (0.95%) (p < 0.001). No differences in species diversity and richness were detected among the different groups. However, LEfSe analysis identified six genera (Eubacterium, Eubacteriaceae, Prevotella, Comamonadaceae, Comamonas, and Firmicutes) significantly enriched in diarrheic calves compared to healthy ones (LDA scores > 2, p < 0.05). Additionally, antibiotic resistance genes for quinolones, β-lactams, chloramphenicol, tetracyclines, and aminoglycosides were detected, with significantly higher prevalence in diarrheic calves. These findings demonstrate distinct microbial and antibiotic resistance profiles between healthy and diarrheic calves, emphasizing the importance of microbial management in controlling calf diarrhea.