本试验旨在研究低聚木糖（XOS）对生长肥育猪血浆生化参数和肌肉脂肪酸组成的影响。选取70日龄、平均体重约为30 kg的杜×长×大三元杂交猪110头，随机分为11组，每组10头（公母各占1/2），单栏饲养。试验设对照组（饲喂基础饲粮），抗生素组（饲喂在基础饲粮中添加0.04 kg/t速大肥、0.2 kg/t抗敌素的饲粮），30~65 kg阶段100、250和500 g/t XOS添加组（在30~65 kg阶段分别饲喂在基础饲粮中添加100、250和500 g/t XOS的饲粮，在66~100 kg阶段均饲喂基础饲粮），66~100 kg阶段100、250和500 g/t XOS添加组（在30~65 kg阶段均饲喂基础饲粮，在66~100 kg阶段分别饲喂在基础饲粮中添加100、250和500 g/t XOS的饲粮）以及30~100 kg阶段100、250和500 g/t XOS添加组（分别饲喂在基础饲粮中添加100、250和500 g/t XOS的饲粮）。于试猪平均体重达100 kg（约170日龄）时，前腔静脉采血，离心分离血浆，测定生化参数；屠宰后取背最长肌和股二头肌样品，测定其脂肪酸组成。结果表明：与对照组相比，30~65 kg阶段，饲粮添加100或500 g/t XOS可显著降低股二头肌中十七烷酸（C17：0）含量（P<0.05）；66~100 kg阶段，饲粮添加250 g/t XOS可显著增加股二头肌中饱和脂肪酸（SFA）+单不饱和脂肪酸（MUFA）含量（P<0.05），添加100或500 g/t XOS可显著增加股二头肌中花生烯酸（C20：1）含量（P<0.05）；30~100 kg阶段，饲粮添加100 g/t XOS可显著增加背最长肌中油酸/亚油酸以及股二头肌中C20：1、MUFA和SFA+MUFA含量（P<0.05），添加100或250 g/t XOS可显著降低血浆总胆固醇浓度（P<0.05），添加500 g/t XOS可显著增加血浆高密度脂蛋白-胆固醇浓度（P<0.05）。综上所述，饲粮添加一定剂量的XOS可通过调控与脂代谢相关的血浆生化参数、增加肌肉中MUFA和SFA+MUFA含量而改善猪肉的风味和营养价值，且以30~100 kg阶段添加100 g/t XOS为最佳。

The present study was conducted to investigate the effects of xylo-oligosaccharide (XOS) on plasma biochemical parameters and fatty acid composition of muscle in growing-finishing pigs. A total of 110 Duroc×Large White×Landrace pigs at 70 days of age with an initial body weight about 30 kg were randomly assigned to 11 groups with 10 pigs per group (male:female=1:1), and fed individually. The experimental groups consisted of control group (pigs were fed a basal diet), antibiotic group (pigs were fed the basal diet supplemented with 0.04 kg/t Stafac and 0.2 kg/t Acrasin), supplementation groups of 100, 250 or 500 g/t XOS during 30 to 65 kg stage (pigs were fed the basal diet supplemented with 100, 250 or 500 g/t XOS during 30 to 65 kg stage, and were fed the basal diet during 66 to 100 kg stage), supplementation groups of 100, 250 or 500 g/t XOS during 66 to 100 kg stage (pigs were fed the basal diet during 30 to 65 kg stage, and were fed the basal diet supplemented with 100, 250 or 500 g/t XOS during 66 to 100 kg stage), and supplementation groups of 100, 250 or 500 g/t XOS during 30 to 100 kg stage (pigs were fed the basal diet supplemented with 100, 250 or 500 g/t XOS). When the average body weight of pigs reached about 100 kg (about 170 days of age), blood samples were collected by precaval vein, and then plasma were obtained by centrifuge for analyzing biochemical parameters. The samples of longissimus dorsi (LD) muscle and biceps femoris (BF) muscle were collected and their fatty acid composition were measured. The results showed that, when compared with the control group, supplementation with 100 or 500 g/t XOS significantly decreased the daturic acid (C17:0) content of BF muscle during 30 to 65 kg stage (P<0.05); during 66 to 100 kg stage, supplementation with 250 g/t XOS significantly increased the content of saturated fatty acid (SFA)+monoun saturated fatty acid (MUFA) of BF muscle (P<0.05), and supplementation with 100 or 500 g/t XOS significantly increased the content of arachidomic acid (C20:1) of BF muscle (P<0.05); during 30 to 100 kg stage, supplementation with 100 g/t XOS significantly increased the ratio of oleic acid (C18:1n9) to linoleic acid (C18:2n6c) of LD muscle (P<0.05), as well as the contents of C20:1, MUFA and SFA+MUFA of BF muscle, supplementation with 100 or 250 g/t XOS significantly decreased the plasma total cholesterol concentration (P<0.05), and supplementation with 500 g/t XOS significantly increased the plasma high-density lipoprotein-cholesterol concentration (P<0.05). Collectively, these findings suggest that diet supplemented with several doses of XOS can increase the muscular contents of MUFA and SFA+MUFA by regulating plasma biochemical parameters related to fat metabolism, which improve the flavor and nutritive value of pork; dietary supplementation with 100 g/t XOS is optimal during 30 to 100 kg stage in growing-finishing pigs.