目的 为抗菌肽在兽医临床上的使用剂量和使用方法提供理论参考。 方法 采用随机数字表法将80头6月龄的西门塔尔牛分为4组，每组20头，分别为对照组、抗菌肽低剂量组、中剂量组、高剂量组。在试验第60天采集西门塔尔牛的静脉血，并应用酶标仪检测西门塔尔牛血清中IL-6、IL-10、TNF-α、IgG、IgA和IgM含量。 结果 在试验第60天，与对照组相比，抗菌肽低剂量组、中剂量组和高剂量组西门塔尔牛血清中IL-10含量分别显著提高30.33%、51.36%、60.85%，IgA含量分别显著提高15.94%、36.23%、43.48%；抗菌肽中剂量组、高剂量组西门塔尔牛血清中IgG含量分别显著提高45.03%、51.27%；各组血清中IgM含量无显著差异。 结论 抗菌肽能够一定程度提升肉牛机体的体液免疫和细胞免疫功能。

Objectives To provide theoretical reference for the dosage and usage of antimicrobial peptides in veterinary clinic. Methods 80 Simmental cattle aged six months were divided into 4 groups using a random number table method, with 20 cattle in each group, namely the control group, group with low-dose of antimicrobial peptide, group with medium dose of antimicrobial peptide, and group with high-dose of antimicrobial peptide. The venous blood from Simmental cattle was collected on the 60th day of the experiment, and the enzyme-linked immunosorbent assay (ELISA) was used to detect the content of IL-6, IL-10, and TNF-α, IL-10, IgG、IgA and IgM in serum from Simmental cattle. Results The content of IL-10 in serum collected from Simmental cattle on the 60th day of the experiment was significantly increased by 30.33%, 51.36%, and 60.85% in the low-dose, medium dose, and high-dose groups of antimicrobial peptides, respectively, compared to the control group. The content of IgA was significantly increased by 15.94%, 36.23%, and 43.48%, respectively. The content of IgG in Simmental bovine serum of medium dose group and high dose group was significantly increased by 45.03% and 51.27%, respectively. There was no significant difference in content of IgM in the serum of all groups. Conclusions Antibacterial peptides can enhance the humoral and cellular immunity of beef cattle to a certain extent.