异育银鲫对糖利用性的研究──饲料糖含量对生长、消化吸收率及体成分的影响

用糊精含量分别为５％、２５％、５０％的三种饲料饲养异育银鲫，研究异育银鲫对糖利用性特点，每个循环过滤水族箱中放养４０尾鱼，每种饲料喂两箱之鱼，饲养六周．摄食不同饲料的异育银鲫增重率有显著差异（ｐ＜０．１），２５％糊精组生长最快，５％糊精组生长最慢．异育银鲫对三种饲料中糖的消化吸收率随着饲料糖含量的增加而极显著提高（ｐ＜ ０．０１），粗蛋白的消化吸收率虽然各组间差异不显著，但也有相同的趋势．摄自不同糖含量饲料的鱼其肌肉含水量随饲料糖含量增加明显下降（ｐ＜０．０５），粗蛋白和脂肪的含量随饲料糖含量的增加而增加，但差异不显著．在禁食２４小时时，肝糖元含量随饲料糖含量增加而显著提高，但能降解肝糖元的肝脏淀粉酶活性差异不显著（ｐ＜０．０５）．

UTILIZATION OF CARBOHYDRATE IN ALLOGYNOGENETIO CRUCIAN CARP-EFFECT OF CARBOHYDRATE CONTENT ON THE GROWTH, DIGESTIBILITY AND BODY COMPOSITION

Diets containing 5%, 25%, 50% dextrin were fed respectively to allogynogenetio crucian carp to investigate its traits of utilizing carbohydrate. Each diet was fed to two aquaria with 40 fish/aquarium in a recirculating filtered rearing system for six week. Results indicated that dietary dex trin level affected the weight gain significantly (p < 0. 1 ). 25% dextrin group results in best weigh gain while 5% dextrin group is the worst. There were sighificant differences among digesibilities of carbohydrate in three diets by crucian carp, increased levels of dietary carbohydrate, elevated digestibity (p < 0 .01 ). Protein digesibility has the same trend as carbohydrate though there was no significant difference. With the increasing of dietary carbohydrate content, crude protein and crude lipid of dorsal muscle increased but insignificant, while moisture decreased markedly (p < 0 .05). After 24hs fast, liver glycogen level elevated with the increasing of dietary carbohydrate , but the amlyase activity, which can breakdown the liver glycogen, showed no significant difference (p < 0 .05).