本文旨在评价不同剂量的低聚木糖（XOS）同时替代抗生素与氧化锌对断奶仔猪生长性能、腹泻率和血浆生化参数的影响，并筛选出其最佳添加剂量。试验选取21日龄的"杜×长×大"断奶仔猪150头，随机分为5组，每组6重复，每重复5头猪。试验各组分别为空白对照组（不添加抗生素、氧化锌）、阳性对照组（添加抗生素、氧化锌）及100、250和500 g/t XOS添加组。记录每栏仔猪的日采食量和腹泻情况，于试验第1、7、21和56天，记录每栏仔猪的体重，计算平均日采食量（ADFI）、平均日增重（ADG）和料重比；前腔静脉采血，分离血浆，检测其生化参数。试验期56 d。结果表明：1）试验第8～21天和第1～56天时，100 g/t XOS组的ADG显著高于空白对照组（P<0.05）；试验第8～21天、第22～56天和第1～56天时，100 g/t XOS组的ADFI显著高于空白对照组（P<0.05）。2）试验第1～7天时100和250 g/t XOS组以及试验第8～21天时3个XOS添加组的腹泻率均显著低于空白对照组（P<0.05），且与阳性对照组无显著差异（P>0.05）。3）试验第7天时，500 g/t XOS组血浆天冬氨酸转氨酶（AST）和乳酸脱氢酶（LDH）活性显著高于阳性对照组（P<0.05）；试验第21天时，100和500 g/t XOS组血浆丙氨酸转氨酶（ALT）活性显著高于空白对照组（P<0.05）；试验第56天时，100 g/t XOS组血浆ALT活性、500 g/t XOS组血浆AST活性、250和500 g/t XOS组血浆碱性磷酸酶活性均显著高于空白对照组和阳性对照组（P<0.05），100 g/t XOS组血浆LDH活性显著高于空白对照组（P<0.05），500 g/t XOS组血浆α-淀粉酶活性显著高于阳性对照组（P<0.05）。上述结果表明，饲粮中添加100～250 g/t的XOS可通过调控断奶仔猪营养素代谢增强肠道健康、减少腹泻，从而促进生长；随着仔猪日龄的增加，可适当增加XOS的添加量。

This study was conducted to evaluate the effects of different doses of xylo-oligosaccharide (XOS) replacing both antibiotics and zinc oxide (ZnO) on the growth performance, diarrhea rate and plasma biochemical parameters of weaned piglets, and to selected its optimal dose of dietary supplementation. A total of 150 weaned Duroc×Large White×Landrace piglets at 21 days of age were randomly assigned to five groups with 6 replicates per group and 5 piglets per replicate, representing blank control group (without antibiotics and zinc oxide), positive control group (containing antibiotics and zinc oxide) and 100, 250 and 500 g/t XOS groups, respectively. Daily feed intake and diarrhea were recorded for each pen. On days 1, 7, 21 and 56 of the experiment, the body weight of piglets in each pen were recorded, and the average daily feed intake (ADFI), average daily gain (ADG) and ratio of feed to gain were calculated, as well as sampling the blood of precaval vein to collect plasma for analyzing the biochemical parameters. The results showed as follows:1) the ADG of 100 g/t XOS group on days 8 to 21 and 1 to 56 of the experiment was significantly higher than that of blank control group (P<0.05), as well as the ADFI of 100 g/t XOS group on days 8 to 21, 22 to 56 and 1 to 56 of the experiment (P<0.05). 2) The diarrhea rates of 100 and 250 g/t XOS groups on days 1 to 7 of the experiment were significantly lower than that of blank control group (P<0.05), as well as of three XOS supplemented groups on days 8 to 21 of the experiment (P<0.05), but there was no significant difference compared with the positive control group (P>0.05). 3) On day 7 of experiment, the activities of aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) in plasma of 500 g/t XOS group were significantly higher than those of positive control group (P<0.05); on day 21 of experiment, the activity of alanine aminotransferase (ALT) in plasma of 100 and 500 g/t XOS groups was significantly higher than that of blank control group (P<0.05); on day 56 of experiment, the activities of ALT in plasma of 100 g/t XOS group, AST in plasma of 500 g/t XOS group and alkaline phosphatase in plasma of 250 and 500 g/t XOS groups were significantly higher than those of blank control group and positive control group (P<0.05), the activity of LDH in plasma of 100 g/t XOS group was significantly higher than that of blank control group (P<0.05), and the activity of α-amylase in plasma of 500 g/t XOS group was significantly higher than that of positive control group (P<0.05). These findings suggest that dietary supplementation with 100 to 250 g/t XOS can enhance intestinal health by regulating nutrient metabolism, reduce the diarrhea, and promote the growth of weaned piglets; with increasing age of the piglets, it may be appropriate to increase the supplementation dose of XOS.