低聚壳聚糖季铵盐对青脚麻鸡生产性能、免疫和抗氧化功能的影响

Effect of quaternized chitooligosaccharide on growth performance, immune and antioxidant function of partridge shank chickens

[目的]本试验旨在研究低聚壳聚糖季铵盐(quaternized chitooligosaccharide,QCOS)对青脚麻鸡生产性能、免疫和抗氧化功能的影响。[方法]将192只1日龄健康青脚麻鸡随机分成4组,每组6个重复,每个重复8只鸡,分别饲喂在基础日粮中添加0(对照组)、2.5、5.0和10.0 mg·kg^(-1) QCOS的试验日粮50 d。养殖过程中记录青脚麻鸡体质量和饲料消耗量用于生产性能的计算,养殖结束后采集胸腺、脾脏、法氏囊、盲肠食糜、血清以及十二脂肠、空肠和回肠黏膜测定免疫器官指数、盲肠菌群数、抗氧化指标和免疫指标。[结果]与对照组相比,日粮中添加QCOS对青脚麻鸡生产性能无显著影响,但添加5.0 mg·kg^(-1) QCOS使青脚麻鸡后期和全期的平均日增重分别提高4.65%、3.38%(P>0.05);QCOS的添加显著提高50 d法氏囊指数(P<0.05),且有降低25 d盲肠内容物中大肠杆菌(P=0.063)和沙门氏菌(P=0.057)数量的趋势;添加2.5、10.0 mg·kg^(-1) QCOS显著提高25 d空肠黏膜的总抗氧化能力(P<0.05),添加10.0 mg·kg^(-1) QCOS显著提高25 d回肠黏膜的总抗氧化能力及总超氧化物歧化酶活性(P<0.05);QCOS的添加显著提高50 d血清和25 d空肠黏膜免疫球蛋白M含量(IgM)(P<0.05),添加5.0 mg·kg^(-1) QCOS显著提高50 d十二指肠黏膜IgG含量(P<0.05),添加10.0 mg·kg^(-1) QCOS显著提高50 d回肠黏膜分泌型IgA的含量(P<0.05),添加2.5、10.0 mg·kg^(-1) QCOS显著提高50 d回肠黏膜IgM和IgG的含量(P<0.05)。[结论]日粮中添加QCOS可改善青脚麻鸡的免疫和抗氧化功能,并在一定程度上抑制肠道有害菌生长。

[Objectives]The aim of this experiment was to study the effect of quaternized chitooligosaccharide(QCOS)on the growth performance,immune and antioxidant function of partridge shank chickens.[Methods]A total of 192 one-day-old healthy chicks were randomly allocated into 4 groups,and one group with 6 replicates of 8 chicks each,and were fed basal diet supplemented with 0(control group),2.5,5.0 and 10.0 mg·kg^-1 QCOS for 50 d,respectively.The partridge shank chickens body mass and feed consumption were recorded during the breeding process for the calculation of production performance,and after the feeding trial,the samples such as thymus,spleen,bursa,chyme in cecum,serum and duodenal,jejunal and ileal mucosa were collected to determine the immune organ index,cecum flora,antioxidant and immune index.[Results]The results showed as follows:compared with the control group,QCOS supplementation did not significantly affect the growth performance of the partridge shank chickens,whereas its supplementation at a dosage at 5.0 mg·kg^-1 numerically increased average daily gain during the finisher and whole experimental periods by 4.65%and 3.38%,respectively(P>0.05).QCOS supplementation,irrespective of dosage,increased the bursa of Fabricius index at 50 d(P<0.05),and tended to decrease the population of Escherichia coli(P=0.063)and Salmonella(P=0.057)in the cecal content at 25 d.Both 2.5 and 10.0 mg·kg^-1 QCOS addition significantly enhanced total antioxidant capacity in the jejunal mucosa at 25 d(P<0.05).10.0 mg·kg^-1 QCOS inclusion significantly increased total antioxidant capacity and total superoxide dismutase activity in the ileal mucosa at 25 d(P<0.05).QCOS addition significantly increased IgM content in the serum at 50 d and jejunal mucosa at 25 d(P<0.05),5 mg·kg^-1 QCOS supplementation elevated IgG concentration in the duodenal mucosa at 50 d(P<0.05),and QCOS supplementation at the dosage of 10.0 mg·kg^-1 significantly increased SIgA content in the ileal mucosa at 50 d(P<0.05).Both 2.5 and 10.0 mg·kg^-1 QCOS inclusion significantly enhanced IgM and IgG contents in the ileal mucosa at 50 d(P<0.05).[Conclusions]The results indicated that QCOS supplementation could improve immune and antioxidant function of partridge shank chickens,and tend to inhibit growth of harmful intestinal bacteria.