罗非鱼对6种碳水化合物饲料原料中营养物质的表观消化率

摘要

This study was conducted to investigated the apparent digestibility of nutrients in six types of carbo-hydrate ingredients for tilapia ( Oreochromis niloticus ) . The six types of carbohydrate ingredients included southern brown rice, wheat middling, corn starch, potato starch, sweet potato starch and cassava starch. The experimental diets were all consisted of 70% basal diet and 30% test feed ingredients, and added 0.04% yttri-um oxide (Y2O3) as an exogenous indicator. A total of 420 genetic improvement of farmed tilapia with an ini-tial average body weight of (35.05±0.62) g were randomly divided into seven groups with three replicates per group and 20 fish per replicate. The fish in control group were fed the basal diet, and the fish in other six groups were randomly fed one of six test diets. After one week feeding with trial diets, the fecal samples were collected by siphon method, and then the apparent digestibility of gross energy, dry mater, ash matter, crude protein, crude lipid, and starch and total saccharides was determined. The results showed that the apparent di-gestibility of gross energy, dry mater, ash matter, crude protein, crude lipid, and starch and total saccharides in the six types of carbohydrate ingredients were 33.89% to 90.85%, 31.50% to 88.01%, 7.73% to 64.37%, 95.74% to 114.38%, 97.63% to 111.51% and 21.49% to 79.73%, respectively. In the six types of carbohy-drate ingredients, the apparent digestibility of gross energy, dry matter, crude protein, and starch and total sac-charides in corn starch was higher than that in other ingredients, and the following was southern brown rice, however, the lowest was found in potato starch. The apparent digestibility of dry matter, and starch and total saccharides existed no significant difference between corn starch and southern brown rice ( P>0.05) . And the apparent digestibility of gross energy, dry mater, crude protein, and total starch and saccharides in the six types of carbohydrate ingredients had the same tendency with that of the six test diets, the higher was found in corn starch and southern brown rice, and the lower was found in potato starch and sweet potato starch. In con-clusion, different sources of carbohydrate led to different apparent digestibility of nutrients for tilapia. The corn starch and southern brown rice are high quality carbohydrate sources for tilapia, and they can be better used in actual feed production to reduce costs. However, potato starch and sweet potato starch should be used less in ti-lapia actual feed production for its lower apparent digestibility, especially the lower available total starch and saccharide.%本试验旨在研究罗非鱼对南方糙米、次粉、玉米淀粉、马铃薯淀粉、甘薯淀粉和木薯淀粉6种碳水化合物原料中总能、干物质、粗灰分、粗蛋白质、粗脂肪、淀粉及总糖的表观消化率.选取初始体均重为(35.05±0.62) g的健康吉富罗非鱼420尾,随机分为7组,每组3个重复,每个重复20尾鱼. 配制由70%的基础饲料和30%的待测原料组成的试验饲料,采用三氧化二钇(Y2O3)为指示剂. 对照组鱼饲喂基础饲料,试验组鱼随机饲喂1 种试验饲料. 各组投喂相应饲料1周后,采用虹吸法收集粪便待测总能、干物质、粗灰分、粗蛋白质、粗脂肪、淀粉及总糖的表观消化率. 结果表明:6种碳水化合物原料中总能、干物质、粗灰分、粗蛋白质、粗脂肪、淀粉及总糖的表观消化率分别为 33. 89%~90. 85%、31. 50%~88. 01%、7. 73%~64. 37%、95. 74%~114.38%、97.63%~111.51%和21.49%~79.73%. 6种碳水化合物原料中,玉米淀粉中总能、干物质、粗蛋白质、淀粉及总糖的表观消化率最高,其次是南方糙米,而马铃薯淀粉最低. 玉米淀粉与南方糙米之间的干物质、淀粉及总糖的表观消化率无显著差异( P>0.05). 6种试验饲料与6种碳水化合物原料中总能、干物质、粗蛋白质、淀粉及总糖的表观消化率的变化趋势一致,均以玉米淀粉和南方糙米较高,以甘薯淀粉和马铃薯淀粉较低. 由此可见,罗非鱼对不同来源的碳水化合物中营养物质的表观消化率不同. 本试验条件下,罗非鱼对玉米淀粉和南方糙米的利用效果较好,可作为罗非鱼优质的碳水化合物源适量添加以降低饲料成本. 而马铃薯淀粉和甘薯淀粉由于其可利用性淀粉及总糖较少,导致表观消化率低,不适宜在罗非鱼饲料配制中大量添加.