本试验比较研究了不同蛋白源(鱼粉,FM;大豆分离蛋白,SPI)基础饲料中添加大豆低聚糖(SBOS)对牙鲆(Paralichthys olivaceus)消化道(胃、幽门盲囊、前肠、中肠和后肠)和肝脏消化酶活性、饲料表观消化率和消化道(胃、小肠)组织结构的影响.分别以FM、SPI作为主要蛋白源,配制了4种等氮等能饲料.其中,饲料FM、SPI分别以FM、SPI作为主要蛋白源;饲料FMO、SPIO分别在饲料FM、SPI基础上添加10%SBOS(水苏糖:2.61%;棉籽糖:0.61%).试验表明:①饲料中添加SBOS普遍降低了牙鲆消化道和肝脏蛋白酶活性,但差异均不显著(p>0.05).FM基础饲料中添加SBOS显著降低了肝脏脂肪酶活性(p<0.05),而对消化道脂肪酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了前肠脂肪酶活性,降低了胃和中肠脂肪酶的活性,而对幽门盲囊、后肠和肝脏脂肪酶活性均无显著影响.FM基础饲料中添加SBOS显著降低了中肠淀粉酶活性,提高了胃淀粉酶活性(p<0.05),而对幽门盲囊、前肠、后肠和肝脏淀粉酶活性无显著影响;SPI基础饲料中添加SBOS显著提高了胃和前肠淀粉酶活性,降低了中肠脂肪酶活性(p<0.05),而对幽门盲囊、后肠和肝脏淀粉酶活性无显著影响;②FM基础饲料中添加SBOS显著降低了饲料干物质表观消化率(p<0.05),而对粗蛋白、粗脂肪和能量表观消化率均无显著影响(p>0.05).SPI基础饲料中添加SBOS对干物质、粗蛋白、粗脂肪和能量表观消化率均无显著影响;③饲料中添加SBOS对牙鲆胃和小肠组织结构均无明显负面影响.试验结果表明,饲料中添加SBOS对牙鲆消化道和肝脏消化酶活性、饲料表观消化率和消化道组织结构均没有表现出明显的负面效应;大豆蛋白源中含有的SBOS不是影响牙鲆对其利用率差的主要因素.%A feeding trim was conducted to investigate the effects of soybean oligosaccharides (SBOS) on the digestive en-zymes activity, feed digestibility and intestinal morphology in juvenile Japanese flounder (Paralichthys olivaceus). Four isonitrogenous and isocaloric practical diets (crude protein 49% , gross energy 19 kJ/g) including only fish meal (FM) or soy protein isolate (SPI) as a sole protein source with (Diets FMO and SPIO) or without (Diets FM and SPI) supplemen-ted SBOS (stachyose, 2.61% ; raffinose, 0.61%) were formulated. Each diet was randomly assigned to triplicate aquaria stocked with 30 fish (initial body weight 1.93±0.02 g) each. Fish were maintained in flow-through aquaria at water temperature ranging from 22.0℃ to 25.0℃ and fed twice (08:00 and 16:00 ) daily to apparent satiation for 8 weeks. Pepsin/protease activities in alimentary tract and liver were generally decreased by supplemental SBOS, but the difference was not significant (p<0.05). Dietary SBOS supplementation significantly decreased the lipase activity in liver (p<0.05), but not the alimentary tract in fish fed FM-based diets. Supplemental SBOS significantly increased the lipase activity in foregnt, decreased in stomach and midgut (p<0.05), but did not affect in pylorus, hindgnt and liver in fish fed SPI-based diets (p>0.05). Supplementation with SBOS significantly decreased the amylase activity in midgut, in-creased in stomach (p<0.05), but did not affect in pylorus, foregnt, hindgnt and liver in fish fed FM-based diets (p>0.05). Supplemental SBOS significantly increased the amylase activity in stomach and foregut, decreased in midgut (p<0.05), but did not affect in pylorus, hindgut and liver in fish fed SPI-based diets (p>0.05). At the same time, dietary SBOS supplementation significantly decreased the apparent digestibility coefficients (ADC) of dry matter, increased the crude lipid and energy (p<0.05), but did not affect the crude protein of Diet FM (p>0.05). ADCs of dry matter, crude protein, crude lipid and energy of Diet SPI were not significantly affected by dietary supplemental SBOS (p>0.05). Intestinal morphology was not obviously influenced by dietary supplemental SBOS in fish fed FM or SPI-based diets. These results indicated that dietary supplemental SBOS did not negatively affect the digestion of Japanese flounder and SBOS was not the main factor which affected the utilization of soy protein sources.
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