棉子糖对刺参幼参生长、生理指标及糖代谢的影响

为研究饲料中添加棉子糖对刺参生长、消化与糖代谢的影响，实验以初始体质量为(11.46±0.06) g的刺参幼参为对象，在基础饲料中添加包膜棉子糖，配制成棉子糖含量分别为0.00%(D1)、0.02%(D2)、0.03%(D3)、0.06%(D4)、0.08%(D5)和0.11%(D6)的6组实验饲料，进行为期67 d的生长实验。结果显示：(1)随着棉子糖含量的增加，刺参的增重率及特定生长率均先升后降，D2～D5组显著高于D1组，D4组达最大值，体壁基本营养成分不受棉子糖含量的影响。(2)肠道蛋白酶、脂肪酶、淀粉酶和超氧化物歧化酶活性均先升后降，D3、D4组显著高于D1组；丙二醛含量先降后升，D4组达最低值；D3～D5组肠道皱襞高度显著高于D1组，D5、D6组出现炎症细胞浸润。(3)葡萄糖激酶、果糖磷酸激酶和丙酮酸激酶活性先升后降，葡萄糖激酶和果糖磷酸激酶活性在D4组达最大值，丙酮酸激酶活性在D3组达最大值；磷酸烯醇式丙酮酸羧激酶活性先上升后平稳，D4～D6组显著高于其他组。(4)葡萄糖激酶、果糖磷酸激酶和丙酮酸激酶基因表达量均先升后降，D2～D6组均显著高于D1组，葡萄糖激酶和果糖磷酸...

Effects of dietary raffinose on growth performance, physiological indices and glycometabolism of juvenile sea cucumber (Apostichopus japonicus)

Raffinose is a functional oligosaccharide, which is utilized by bifidobacterium and lactobacillus in the intestines, and plays an important role in the digestive physiology and antioxidant properties of the body. Juvenile sea cucumbersApostichopus japonicus has high nutritional value. This study investigated the effects of dietary raffinose on physiological indices and genes related to glycolmetabolism of juvenile sea cucumber A.japonicus. Six experimental diets were formulated to contain with the graded levels of raffinose [0 (D1, control group), 0.02% (D2), 0.03% (D3), 0.06% (D4), 0.08% (D5) and 0.11% (D6) dry diets]. Each diet was randomly assigned to triplicate tanks of sea cucumber juveniles with initial body weight (11.46±0.06) g for 67 days. The results showed that there were no differences on survival rate (SR) andratio of intestine weight to body wallweight(IBR) among all groups. Both weight growth rate (WGR) and the specific growth rate (SGR)increased with increasing raffinose content until reaching peak levels at 0.06% dietary raffinose, but decreased thereafter. The WGR and SGR of D2, D3, D4and D5 groups were significantly higher than D1 group. The WGR reached maximum value of 84.41% in the D4 group.There were no significant effects onmoisture, crude protein, crude fat and ash of body wall of Apostichopus japonicus. The activities of intestinal protease, lipase,amylase and superoxide dismutase were increased when dietary raffinose content increased from 0 to 0.06% and then decreased. The proteaseand the lipase of D4 groups were significantly higher than other groups, meanwhile, and the amylase of D5 group was significantly higher than other groups. The superoxide dismutase activity of D3, D4 and D5 groups were significantly higher than the control group. The content of malondialdehyde was firstly decreased and then increased, and reached the lowest value in D4 group. There was no significant difference among the activities of alkaline phosphatase and acid phosphatase. The height of intestinal folds in D3, D4 andD5 groups was significantly longer than that in the control group, and inflammatory cell infiltration appeared in D5 andD6 group. There were no significant difference in the ratio of intestine weight to body wall weight and the thickness of muscularis among all groups. With the increase of raffinose content, the activities of glucokinase, fructosophosphate phosphokinase and pyruvate kinase increased first and then decreased.while the activities of phosphoenolpyruvate carboxykinase increased firstand then tend to be stable, The glucokinase activitie of D3 and D4 groups were significantly higher than the control group. The fructosophosphate phosphokinase activitie of D2, D3 and D4 groups were significantly higher than the other groups, and reached maximum value in the D4 group.. The pyruvate kinase activitie of D2, D3, D4 and D5 groups were significantly higher than the other groups. The phosphoenolpyruvate carboxykinase activitie of D4, D5 and D6 groups were significantly higher than the other group.The expression levels of GCK, PFK and PK genes increased firstly and then decreased, and were significantly higher in each experimental group than in the control group. The expression levels of GCK and PK genes reached the maximum in D4 group, and PFK gene expression levels in D4 and D5 groups were significantly higher than those in other groups.The results showed that dietary raffinose increased the glucose metabolism efficiency, improved the digestive physiology and antioxidant capacity of the body, and promoted the growth of the sea cucumber juvenile. With the weight gain rate as an evaluation indicator, quadratic regression analysis showed that the optimum dietary raffinose of sea cucumber juvenile was 0.063% diet.As a functional oligosaccharide, raffinose plays an important role in the digestion, metabolism and antioxidant of A.japonicus, and has deep research significance in the application of compound feed of A.japonicus.