大菱鲆幼鱼对几种蛋白质源中营养物质的表观消化率及膨化处理对其产生的影响

本试验旨在研究大菱鲆(Scophthalmus maximus L.)对秘鲁红鱼粉、豆粕、葵花粕和玉米蛋白粉中干物质、粗蛋白质、氨基酸和总能的表观消化率,以及膨化处理对其产生的影响。试验饲料由70%基础饲料和30%待测蛋白质源组成,并添加0.1%的三氧化二钇(Y2O3)作为外源指示剂,将其分别制作成正常颗粒料和膨化颗粒料。将平均体重为(8.98±0.01)g的大菱鲆幼鱼随机分成10组,每组3个重复,每个重复40尾鱼,按照不同处理分别投喂相应饲料,喂养2周后采用后肠挤压法收集粪便样品至第6周。结果表明:大菱鲆幼鱼对4种蛋白质源中干物质、粗蛋白质、总氨基酸和总能的表观消化率分别为22.33%~65.50%、48.97%~85.28%、47.70%~84.14%和44.50%~81.16%。其中,秘鲁红鱼粉的各营养物质的表观消化率均显著高于3种植物蛋白质源(P0.05);3种植物蛋白质源中以豆粕中粗蛋白质的表观消化率最高,葵花粕次之,玉米蛋白粉最低;各待测蛋白质源中总氨基酸表观消化率的变化趋势与粗蛋白质表观消化率基本一致。经膨化处理后,大菱鲆对4种蛋白质源中营养物质的表观消化率均得到改善,尤其是3种植物蛋白质源,效果显著(P0.05),膨化处理后4种蛋白质源中干物质、粗蛋白质、总氨基酸和总能的表观消化率分别为24.26%~70.87%、57.20%~85.33%、68.27%~87.09%和49.23%~84.35%。由此得出,膨化处理能够提高大菱鲆幼鱼对秘鲁红鱼粉、豆粕、葵花粕和玉米蛋白粉中营养物质的表观消化率。

Nutrient Apparent Digestibility Coefficients of Several Protein Sources in Juvenile Turbot (Scophthalmus maximus L.) and Effects of Extrusion Treatment on Them

This experiment was conducted to determine the apparent digestibility coefficients ( ADC ) of dry matter (DM), crude protein (CP), amino acid (AA) and gross energy (GE) of Peruvian red fish meal, soybean meal, sunflower meal and corn gluten meal in juvenile turbot ( Scophthalmus maximus. L ) and the effects of extrusion treatment on them. Test diets contained 70% basal diet and 30% tested protein source, all diets contained 0.1% yttrium trioxide as an exogenous indicator and were made into normal pellet feed and ex?truded pellet feed, respectively. Juvenile turbot with the average body weight of (8.98±0.01) g were randomly divided into 10 groups with 3 replicates in each group and 40 fish in each replicate. The fish in different group were fed with the corresponding diet, and fecal samples were collected with the method of squeezing the hind?gut after 2 weeks and this work was not completed until the sixth week. The results showed that the ADC of DM, CP, total AA and GE of four protein sources were 22.33% to 65.50%, 48.97% to 85.28%, 47.70% to 84.14% and 44.50% to 81.16%, respectively. Fish meal showed the significantly higher ADC for all nutrients compared other three protein sources ( P<0.05) . Soybean meal had the highest ADC of CP among three plant proteins, the next was sunflower meal, and corn gluten meal presented the lowest value. ADC of total AA of each protein source presented the similar tendency with CP. Apparent digestibility of four protein sources espe?cially the plant protein sources significantly improved after expanding treatment (P<0.05), and the ADC of DM, CP, total AA and GE of four protein sources were 24.26% to 70.87%, 57.20% to 85.33%, 68.27% to 87.09% and 49.23% to 84.35%, respectively. The results indicate that extrusion treatment contributes to the improvement of ADC of Peruvian red fish meal, soybean meal, sunflower meal and corn gluten meal in juven?ile turbot.