Development of Non-fish meal diet for fish

本研究旨在为黄尾鱼无鱼粉干饲料的研制提供一些基础资料。为了提高非鱼粉膳食的膳食价值，必需氨基酸（EAA）的补充是必要的，考虑到它们在血浆中的吸收必须与来自膳食蛋白质的那些同步，以使它们有效利用。因此，通过饲喂三种不同类型的饲料，研究了黄尾鱼餐后血浆和饲料中FAA的变化。（软干颗粒（SDP）、挤压颗粒（EP）和单湿颗粒（SMP）），所有这些颗粒具有几乎相同的配方，具有或不具有补充的EAA。发现补充的EAA被黄尾鱼有效地吸收，改善了饮食之间不同的饲料性能，对于SDP最高，对于SMP组最低。然而，鱼的生长性能与EAA的非鱼粉饲料喂养的鱼是劣于对照鱼粉饲料的鱼，尽管事实上，前者与EAA强化，以模拟对照饲料的水平。虽然补充EAA被有效地吸收，血浆蛋氨酸水平显着高于那些喂对照饮食的鱼。这可能导致氨基酸不平衡，可能降低饲料性能。为了有效利用，补充结晶EAA进入血浆的吸收必须与来自膳食蛋白质的吸收同步，并且发现这与膳食从胃中排出的时间密切相关。因此，利用效率不同类型的饮食之间的基础上，他们的物理特性，如硬度。

This research was conducted to gather some basic information necessary for the development of non-fish meal dry diets for yellowtail. For the improvement of dietary value of non-fish meal diets supplementation of essential amino acids (EAA) is necessary, taking into consideration that their absorption into plasma must be synchronized with those derived from dietary protein for their effective utilization. Therefore, postprandial changes of FAA in plasma and feed digesta were examined in yellowtail by feeding them three types of diets {(soft-dry pellet (SDP), extruded pellet (EP), and single moist pellet (SMP)}, all having almost the same formulation with or without supplemental EAA.The supplemental EAA were found to be efficiently absorbed by yellowtail improving feed performances differing between diets, being highest for the SDP and lowest for the SMP group. However, the growth performance of fish fed the non-fish meal diets with EAA were inferior to those of fish on the control fish meal diet, in spite of the fact that the former were fortified with EAA to simulate the levels of the control diet. Although supplemental EAA were efficiently absorbed, the plasma methionine levels were markedly higher than those of fish fed the control diet. This may have caused an amino acid imbalance may have lowering the feed performances. For effective utilization, absorption of supplemental crystalline EAA into plasma must be synchronized with those derived from dietary protein, and this was found to be closely related to evacuation timing of the diet from the stomach. Thus the utilization efficiency differed between types of diets based on their physical properties such as hardness.