本试验旨在确定猪圆环病毒2型（PCV2）攻击下，玉米豆粕型日粮中生物素的适宜添加水平及其对仔猪部分免疫指标及生产性能的影响。将28日龄断奶、PCV2抗体检测阴性的（杜×长×大）三元杂交仔猪54头，平均分成6个处理，每个处理9个重复，每个重复1头猪。试验第1天试验猪全部口鼻接种PCV2，分别饲喂添加了0、0.10、0.20、0.30、0.40和0.50 mg/kg生物素的日粮，试验期35 d。结果显示：（1）添加0.50 mg/kg生物素时，仔猪35 d的日增重、料重比显著高于0 mg/kg生物素添加组 （P<0.05）;(2)日粮中添加0.30～0.50 mg/kg生物素，试验第21 天和第35天，仔猪血清IgG水平显著高于0~0.20 mg/kg添加组 （P<0.05）；(3)添加0.30 mg/kg生物素，可以提高试验后期仔猪血清IFN-γ水平；(4)35 d日增重、料重比，以及接种后21和35 d仔猪血清IgG水平与生物素添加量分别呈2次及3次曲线回归。由结果得出，PCV2攻击下，日粮中添加0.30～0.50 mg/kg的生物素，对提高仔猪生产性能，提高IgG及后期IFN-γ水平有良好效果。

The purpose of the study was to determine the optimized biotin levels in corn-soybean meal diet for the growth performance and some immune indices in weaned piglets challenged with porcine circovirus type 2 (PCV2). Fifty four 28 -day-old weaned pigs (Duroc × Landrace ×Yorkshire) with negative PCV2 antibody and initial body weight of (6.93±0.721) kg were allocated into 6 treatments with 9 replicates per treatment and 1 pig per replicate. On day 1 of the experiment, all pigs were inoculated with PCV2, and the basal diet was corn-soybean meal diet, and biotin was added to the basal diet at rates of 0, 0.10, 0.20, 0.30, 0.40 and 0.50 mg/kg diet, respectively. The experiment lasted for 35 days. The results showed that average daily gain (ADG) and  F/G of 35 days were significantly improved with 050 mg/kg biotin addition compared with those with 0 mg/kg (P<0.05); adding 0.30～0.50 mg/kg biotin significantly increased the serum IgG concentration (P<0.05) compared with that of 0~0.20 mg/kg; serum IFN-γ level in 0.30 mg/kg biotin group was higher in the later period of experiment than that of other groups; with biotin additive levels increasing, the ADG and F/G of 35  days and IgG concentration on day 21 and day 35 after inoculation showed quadratic or cubic curve regression. In conclusion, supplementation of 0.30～0.50 mg/kg biotin could significantly improve the serum IgG,IFN-γ concentration and the growth performance in the piglets challenged with PCV2.