Context Dietary supplementation of essential oils or in combination with a Bacillus probiotic was investigated as an antibiotic growth promoter for weaned pigs. Aims To evaluate the effect of essential oils (i.e. thymol and carvacrol mixture) or in combination with a probiotic strain (i.e. Bacillus subtilis PB6) on the growth performance, diarrhoea incidence, ammonia emission and serological profiles of weaned pigs. Methods A total of 96 crossbred ([Yorkshire × Landrace] × Duroc) weaned pigs were randomly allotted to one of six treatments based on sex and initial bodyweight. Each group was distributed into four replicates with four pigs each according to a randomised complete block design. The treatments were: (i) positive control, basal diet supplemented with colistin 150 g/tonne and amoxicillin 200 g/tonne; (ii) negative control, basal diet without supplementation; (iii) T3, basal diet supplemented with essential oils 300 g/tonne; (iv) T4, basal diet supplemented with essential oils 600 g/tonne; (v) T5, basal diet supplemented with essential oils 1000 g/tonne; and (vi) T6, basal diet supplemented with essential oils 300 g/tonne diet and Bacillus probiotics 1000 g/tonne. Key results The piglets fed with supplements had a significantly higher average daily gain and lower incidence of diarrhoea than the piglets in the negative control (P = 0.001). Feeding the essential oils alone or in combination with probiotics significantly reduced faecal ammonia emission (P = 0.027) and blood urea nitrogen (P = 0.039), while markedly increasing the serum immunoglobulin G concentration of weaned pigs compared with the negative control treatment (P = 0.014). The difference in time of blood collection had significant effects on blood urea nitrogen and immunoglobulins (P = 0.001). However, no significant differences emerged in average daily feed intake, gain : feed ratio, feed efficiency and antibody against swine fever among the treatments. Conclusions Diet supplementation with essential oils or in combination with probiotics improved growth performance and immunity, and lowered ammonia emissions and diarrhoea incidence of weaned pigs. Implications These findings provide a basis for the application of phytogenic compounds and probiotics as antibiotic growth promoter alternatives in post-weaning diets for pigs.

中文翻译：

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日粮中添加精油和芽孢杆菌益生菌对断奶仔猪生长性能、腹泻和血液代谢物的影响

背景 研究了在日粮中添加精油或与芽孢杆菌益生菌组合作为断奶猪的抗生素生长促进剂。目的 评估精油（即百里酚和香芹酚混合物）或与益生菌菌株（即枯草芽孢杆菌 PB6）组合对断奶猪的生长性能、腹泻发生率、氨排放和血清学特征的影响。方法 将总共 96 头杂交（[Yorkshire × Landrace] × Duroc）断奶猪根据性别和初始体重随机分配到六种处理中的一种。根据随机完整区组设计，每组被分配为四个重复，每组四头猪。处理为：(i)阳性对照，添加粘菌素150克/吨和阿莫西林200克/吨的基础饮食；(ii) 阴性对照，没有补充的基础饮食；(iii) T3，基础饮食补充精油 300 克/吨；(iv) T4，基础饮食补充精油 600 克/吨；(v) T5，基础日粮补充精油 1000 克/吨；(vi) T6，基础日粮，添加了 300 克/吨的精油和 1000 克/吨的芽孢杆菌益生菌。主要结果 与阴性对照仔猪相比，饲喂补充剂的仔猪平均日增重明显更高，腹泻发生率更低 (P = 0.001)。单独饲喂精油或与益生菌联合饲喂可显着降低粪便氨排放量（P = 0.027）和血尿素氮（P = 0.039），同时与阴性对照相比显着增加断奶猪的血清免疫球蛋白 G 浓度（P = 0.014）。采血时间的差异对血尿素氮和免疫球蛋白有显着影响（P=0.001）。然而，处理之间在平均日采食量、增重：饲料比、饲料效率和猪瘟抗体方面没有出现显着差异。结论 日粮中添加精油或与益生菌联合使用可提高断奶仔猪的生长性能和免疫力，降低氨排放和腹泻发生率。意义 这些发现为将植物源性化合物和益生菌作为抗生素生长促进剂替代品用于猪断奶后日粮提供了基础。处理中饲料效率和猪瘟抗体。结论 日粮中添加精油或与益生菌联合使用可提高断奶仔猪的生长性能和免疫力，降低氨排放和腹泻发生率。意义 这些发现为将植物源性化合物和益生菌作为抗生素生长促进剂替代品用于猪断奶后日粮提供了基础。处理中饲料效率和猪瘟抗体。结论 日粮中添加精油或与益生菌联合使用可提高断奶仔猪的生长性能和免疫力，降低氨排放和腹泻发生率。意义 这些发现为将植物源性化合物和益生菌作为抗生素生长促进剂替代品用于猪断奶后日粮提供了基础。