Effects of phytogenic feed additives on the growth, blood biochemistry, and caecal microorganisms of White Roman geese

This study investigated the effects of Lycium chinense Miller stem (LCM) and Origanum vulgare Linn (oregano) essential oil on growth, blood biochemistry, and caecal microorganisms in White Roman goose. A total of 96-day-old White Roman geese were randomly allocated to a control group and three treatment groups. The G 0.05 diet was enriched with 0.05% LCM extract, the G 0.5 diet was enriched with 0.5% LCM extract, and the O 0.05 diet was enriched with 0.05% oregano essential oil. Each treatment was allotted to three pens, with four males and four females per pen. Geese were fed for 83 days. Geese in group O 0.05 had greater body weight gain than those in groups G 0.05 and G 0.5 in the first 28 days (P < 0.05), whereas the geese in group O 0.05 also showed greater body weight gain than those in control and G 0.05 groups in total 83 days (P < 0.05). No significant differences in serum creatinine, glutamic oxaloacetic transaminase, glutamic-pyruvic transaminase, cholesterol, low-density lipoprotein, or high-density lipoprotein were observed. Serum glutathione peroxidase concentrations were signifi-cantly higher for geese in group G 0.5 (P < 0.05) than for the control group at 83 days of age. At 87days of age, one male and one female per pen were slaughtered, and the caecum contents were collected for gene sequencing by 16S ribosomes. No significant differences in microbial alpha diversity were observed. In conclusion, supplementation with 0.05% oregano essential oil increased body weight gain for 83 days. In addition, supplementation with 0.5% LCM extract increased glutathione peroxidase activity at 83 days of age (P < 0.05). In summary, our study showed that phytogenic feed additives improve growth and have antioxidant and immune properties in geese.