中文摘要：

利用放射免疫测定（RIA）检测了从初生到断奶后12个日龄点仔猪血液免疫球蛋白IgG和SIgA的水平及其变化动态,利用流式细胞术（FCM）检测了仔猪外周血T淋巴细胞亚群的变化动态。结果表明：（1）仔猪血液IgG在刚出生时（0d）含量为0,吸吮初乳后（0.5d）水平迅速上升,至1d时达到峰值,而在3d时IgG水平出现急剧下降,在7d时达到第2次高峰,但从10d显著下降随后基本保持稳定,至35d时血液IgG水平又出现大幅度升高,达到4.74mg/mL。（2）仔猪血清SIgA水平变化幅度相对较小,一出生即有较高水平,3d时达到峰值,从4d起开始缓慢下降,至28d断奶时降至最低,而35d时SIgA水平有所回升。（3）仔猪外周血T细胞（CD3＋）和CD4＋T细胞、CD8＋T细胞的百分数随着日龄增长而逐渐升高,但35d时CD3＋T细胞和CD4＋T细胞水平均有显著下降;CD4＋/CD8＋T细胞比值随日龄逐渐降低,至35d时降至最低。仔猪血清IgG水平的变化提示仔猪肠关闭的时间应在出生后48～72h之间,而血清SIgA含量达到峰值的时间（3d）与母猪初乳IgA峰值时间相一致,提示母乳IgA对于仔猪早期黏膜免疫极为重要。断奶应激可降低T细胞各亚群的水平,抑制细胞免疫能力,但对于体液免疫没有明显影响。

英文摘要：

Titration of serum IgG and SIgA levels in piglets,from newborn to postweaning,was taken by radioimmunoassay（RIA）,while peripheral T lymphocyte subsets were analysed by flowcytometry（FCM）.The RIA results showed that the piglets at birth presented no IgG in the body before suckling,whereas the IgG level promptly increased after having sucked the colostrum,reaching peak concentration at the first day,dropping sharply at the thied day,but recovering to the second day peak at the seventh day,then a distinct decrease occurred at the tenth day followed by a period of relative stable levels,and then the IgG titer reached maximum at the 35th day with a concentration of 4.74 mg/mL.The SIgA level was relatively high even at birth,reaching peak concentration at the third day and then slowly decreasing till approaching the lowest at the 28 th.The percentage of swine peripheral blood T lymphocyte（CD3 ＋）,CD4＋ T cell and CD8＋ T cell increased with the date of age,however a great decrease was observed at the 35 th in both CD3＋ and CD4＋ T cells.The ratio of CD4 ＋/CD8 ＋ T cell showed a reverse trend of change from the T subsets,which reached the minimum at the 35th.In conclusion,the serum IgG levels in piglets imply that the timing of ＂gut-closure＂ is at 48～72 h of age,whilst maternal IgA plays a crucial role in the mucosal immunity of the young.It also indicates that weaning stress inhibits cell-mediated immunity by down regulating,but shows no apparent influence on humoral immunity.