不同淀粉源对膨化饲料颗粒质量及吉富罗非鱼表观消化率的影响

摘要

This experiment was conducted to study the effects of three starch sources( corn,wheat flour and cassava starch)on pellet quality of extruded feed and apparent digestibility of dry matter ,crude protein and gross energy of genetic improvement of farmed tilapia. Five diets were prepared by using 40% corn( group D1),40% wheat flour( group D2),40% cassava starch( group D3),35% wheat flour+5% cassava starch ( group D4)and 35% corn+5% cassava starch( group D5)as starch sources,respectively. Each diet was fed 4 replicates of 30 fish of an initial body weight of 95 g for 70 days. The results showed as follows:1)the ex-pansion(99.3%)and starch gelatinization(99.2%)in group D3 were significantly higher than those in other groups( P<0. 05 ),and the bulk density and hardness were the lowest,correspondingly;the expansion (56.3%)and starch gelatinization(92.9%)in group D1 were significantly lower than those in other groups ( P<0.05),and the bulk density and hardness were the highest,correspondingly. 2)The amylopectin content and expansion showed a positive correlation(y=-1.895x2+105.4x-1 341.4,R2=0.905),the expansion and bulk density showed a negative correlation(y=-0.62x+489.1,R21=0.737),the starch gelatinization and ex-pansion showed a positive correlation(y=6.263x-525.9,R22=0.682),the expansion and hardness showed a negative correlation( y=-7.896x+5 238,R23=0.644). 3)The apparent digestibility of crude protein and gross energy in groups D2 and D4 was significantly higher than that in groups D1 and D2( P<0.05),there were no difference in dry matter apparent digestibility among all groups( P>0.05). In the present study,35% wheat flour+5% cassava starch as starch source has the best effect.%本试验旨在研究3种不同淀粉源（玉米、面粉、木薯淀粉）对膨化饲料颗粒质量及吉富罗非鱼干物质、粗蛋白质和总能表观消化率的影响。共配制淀粉源分别为40％玉米（ D1组）、40％面粉（ D2组）、40％木薯淀粉（ D3组）、35％面粉＋5％木薯淀粉（ D4组）和35％玉米＋5％木薯淀粉（ D5组）的5组饲料，分别饲喂初始体重为95 g的吉富罗非鱼70 d，每组4个重复，每个重复30尾鱼。结果表明：1）D3组饲料的膨胀度（99．3％）和淀粉糊化度（99．2％）显著高于其他组（P＜0．05），相应其容重和硬度最低；D1组饲料的膨胀度（56．3％）和淀粉糊化度（92．9％）显著低于其他组（ P＜0．05），相应其容重和硬度最高。2）饲料中支链淀粉含量与膨胀度呈正相关（ y＝-1．895x2＋105．4x-1341．4，R2＝0．905），膨胀度与容重间存在负相关（ y＝-0．62x＋489．1，R21＝0．737），淀粉糊化度和膨胀度呈正相关（ y＝6．263x-525．9，R22＝0．682），膨胀度和硬度呈负相关（ y＝-7．896x＋5238，R23＝0．644）。3）D2、D4组粗蛋白质和总能表观消化率显著高于D1、D3组（ P＜0．05），各组干物质表观消化率差异不显著（ P＞0．05）。综合本研究结果，以35％面粉＋5％木薯淀粉为淀粉源时效果最佳。