海带废渣水平对罗非鱼饲料蛋白质和氨基酸消化率的影响

Effects of dietary Laminaria residue levels on crude protein and amino acids digestibility of the tilapia

饲料中海带废渣使用量分别为０％、５％、１０％、２０％和３０％等５个水平，鱼粉使用量均为５％，实测粗蛋白含量平均为２３．３％．结果表明，添加海带废渣饲料组的尼罗罗非鱼（Ｏｒｅｏｃｈｒｏｍｉｓｎｉｌｏｔｉｃｕｓ）的总氨基酸表观消化率高于对照组，平均为７９．３％，其中，１０％、２０％、３０％海带废渣组的饲料氨基酸表观消化率显著高于对照组（Ｐ＜０．０５）；其总表观消化率和粗蛋白表观消化率则略低于对照组．不同氨基酸的表观消化率以胱氨酸的为最高．饲料中的氨基酸含量与其消化率为曲线正相关．

Five sorts of diets were composed to contain 0%, 5%,10%, 20% and 30% Laminaria residues and 5% fish meal was used in each sort of diet and the dietary crude protein level was around 23.3% . The results showed that total apparent digestibilities of amino acids of  Laminaria residue groups were higher than that of contrast group of tilapia, Oreochromis niloticus, in which, the average digestibility was 79.3% and the digestibilities of 10%, 20% and 30% Laminaria  residue groups were significantly higher than contrast group respectively (P<0.05), but their total dietary digestibility and crude protein digestibility were lower slightly than those of contrast group. The apparent digestibility of cystine(Cys) was hightest in dietary amino acids. There was positive correlation between contents of amimo acids and their digestibilities.