试验研究了不同剂量水平绿茶粉对老年犬免疫功能的影响。选取10岁初始体重34.5~37.5 kg的拉布拉多72头,随机分为4组,分别饲喂添加0、1 000、2 000、4 000 mg/kg绿茶粉饲料,每组3个重复,每个重复6头犬,试验进行9周。结果显示,添加量为2 000 mg/kg时,T淋巴细胞转化率达到最高,与对照组相比,提高了47.83%（P<0.05）。低添加量绿茶粉（1 000 mg/kg）降低了老年犬血清中溶菌酶的含量,差异不显著（P>0.05）,但2 000 mg/kg和4 000 mg/kg绿茶粉处理组溶菌酶含量分别提高了32.76%（P<0.01）和19.39%（P<0.01）。同时提高了血清中总蛋白含量（P>0.05）,随着绿茶粉添加量的增加,球蛋白含量有所增加,4 000 mg/kg组球蛋白含量高于对照组,但差异不显著（P>0.05）。

The aim of experiment was to investigate the effects of different levels of green tea powder on immunological function in aged canines. Seventy two ten year-old aged canines with an average body weight of 34.5~37.5 kg were randomly allocated into 4 groups with 3 replicates of 6 canines, four diets containing green tea powder (0, 1 000, 2 000, 4 000 mg/kg) were given to feed the canine for 9 weeks. The results indicated that containing green tea powder (2 000 mg/kg) group T Lymphocyte Transformation Rate(LTT) reached the highest, increased significantly (P<0.05) up to 47.83%. Although lower adding green tea powder (1 000 mg/kg) reduced serum lysozyme activity in the aged canine, but not significantly (P<0.05), and 2 000 mg/kg and 4 000 mg/kg groups serum lysozyme activity in aged canine were increased obviously (P<0.01). Compared with control the contents of lysozyme in the 2 and 3 treatments increased 32.76% and 19.39% respectively. At the same time, that addition of green tea powder, the total protein(TP) in blood were slightly higher than those in control (P>0.05). When the levels of green tea power increased, the contents of globulin increased. Treatment 3(4 000 mg/kg) were higher than those in the control group(P>0.05).