低魚粉飼料對赤鰭笛鯛成長的影響

Abstract

赤鰭笛鯛體色鮮紅，肉質細緻甜美及市場價值高。將可成為台灣海水箱網養殖的主要魚種。蛋白質為水產飼料中最貴的原料，然而魚粉為養殖魚的主要蛋白質來源。目前商業飼料已利用不同蛋白質來源來減低成本。本研究在於探討赤鰭笛鯛飼料配方上，分別利用烏賊粉和植物性原料取代部分魚粉之效果。本研究分為兩個實驗。 實驗一：對照組(FM60)以60 %魚粉為飼料蛋白質來源，實驗組則添加烏賊粉(S)和羽扇豆粉(L)、菜籽粕(R)及玉米蛋白(C)等植物性原料取代魚粉，分為SL、SR、SC、SLR、SLC、SRC及SLRC七組，測試其對於赤鰭笛鯛(初重約3.5克)之成長效果。經42天飼養，以SLRC組成長及飼料效率最差。然而SLC組的成長和飼料效率皆和對照組無顯著差異，因此魚粉含量可由60%降至30%對赤鰭笛鯛的成長無影響。 實驗二：降低飼料中魚粉含量，由於菜籽粕所含的植酸較高，會影響蛋白質的吸收，所以在飼料配方中，降低菜籽粕的含量從10%降至5%。此實驗共分為FM60、LC、SLC、FM25、SLRC、FM20等六組。飼養42天後，FM20組的增重率及飼料效率和全魚粉組(FM60)皆相近，因此在本研究能以三種植物性原料和烏賊粉取代魚粉40%。

Red striped snapper (Lutjanus erythropterus) , the skin of this fish is bright red and with tasty flesh, and its value in the market is usually high. It is most likely developing as the main kind of cultured fish using the seawater net cage culture in Taiwan. One of the most expensive ingredients in feed production is protein ; however, fish meal is the major protein source in feeds for intensive fish farming. Different protein sources are used for commercial feed production to reduce costs at present. A study was designed to evaluate the level of substitution of fish meal in diets for red striped snapper when a mixture of feedstuffs of plant protein and squid meal was used. This study was divided into two trails. In the first trail, the control diet (FM60) contained 60% fish meal and seven other experimental diets (SL, SR, SC, SLR, SLC, SRC, SLRC) in which protein from fish meal was substituted by protein from lupin (L), rapeseed (R), corn protein (C) and squid meal (S). Red striped snapper (initial weight about 3.5g) were fed these diets for 6 weeks and growth parameters were recorded. The final body weight, weight gain and feed efficiency ratio of the group SLRC was the lowest than other groups. Then between the group SLC and control diet, there were no marked differences in the growth performance. So the content of fish meal in diet could decrease from 60% to 30%. In the second trail, we attempted to reduce the contents of fish meal in diet. Owing to the rapeseed meal contained high level of phytic acid that could involve the bioavailability of protein, it was necessary to reduce its content in diet. The content of rapeseed meal was reduced from 10% to 5% at experiment diet. The trail was divided into six groups (FM60, LC, SLC, FM25, SLRC, FM20). After 6 weeks of feeding, the growth performance of the group FM20 had no significantly differences with the control diet. Therefore in our study, about 40% of fish meal could be replaced with plant ingredients and squid meal.