仿刺参幼参对缬氨酸最适需求量的研究

Optimum dietary valine requirement of juvenile sea cucumber Apostichopus japonicus

摘要:

为探讨仿刺参幼参对缬氨酸的最适需求量，在基础饲料中添加0、0.80%、1.60%、2.40%、3.20%和4.00%的包膜缬氨酸，配制缬氨酸含量分别为0.61%（D1，对照组）、1.14%（D2）、1.46%（D3）、1.73%（D4）、2.17%（D5）和2.64%（D6）的实验饲料，饲喂体质量为（9.20±0.12）g的仿刺参幼参8周。结果显示，①添加缬氨酸对仿刺参幼参的成活率（SR）无显著影响；增重率（WGR）和特定生长率（SGR）均呈先上升后下降趋势，D4组显著高于其他各组；②添加缬氨酸对肠壁比和肠长比均无显著影响；③体壁粗蛋白和粗脂肪含量均呈先上升后下降趋势，D4组粗蛋白含量显著高于其他各组，添加缬氨酸显著提高了体壁组氨酸、缬氨酸、必需氨基酸和总氨基酸含量，降低了亮氨酸、异亮氨酸和酪氨酸含量；④肠道中总超氧化物歧化酶（T-SOD）和总抗氧化能力（T-AOC）随缬氨酸添加量的增加呈上升趋势，D1组显著低于其他各组；丙二醛（MDA）呈先下降后上升趋势，D4组显著低于对照组；⑤肠道蛋白酶和脂肪酶活力均呈先上升后下降趋势，D3组蛋白酶显著高于其他各组，淀粉酶活力不受缬氨酸含量的影响。综上，饲料中添加适宜的缬氨酸显著提高了仿刺参的生长性能和非特异性免疫力，改变了体壁的常规成分和氨基酸含量。以增重率为评价指标，经折线回归分析得出，体质量为9.20 g的仿刺参其配合饲料中缬氨酸最适含量为1.79%（9.18%饲料蛋白质）。

关键词:仿刺参;缬氨酸;生长性能;免疫

Abstract:

An 8-week feeding trial was conducted to determine the dietary valine requirement of juvenile sea cucumber Apostichopus japonicus with initial body weight (9.20±0.12) g. Six experimental diets were formulated with the graded valine levels (0, 0.80%, 1.60%, 2.40%, 3.20% and 4.00% dry diets, respectively). The six trial diets were determined to contain valine of [0.61% (D1), 1.14% (D2), 1.46% (D3), 1.73% (D4), 2.17% (D5) and 2.64% (D6) dry diet], respectively. The results showed that: ① No significant differences in the survival rate (SR) were found among dietary treatments ; the weight growth rate (WGR) and the specific growth rate (SGR) increased with increasing levels of valine up to 1.73% diet, and thereafter, declined. ② There were no significant effects on ratio of intestine weight to body wall weight (IBR) and ratio of intestine length to body length (IBL) of sea cucumber. ③ Crude protein and crude lipid of body wall increased initially, then decreased, and crude protein of diet D4 was significantly higher than that of any other groups. Dietary valine significantly increased His, Val, essential amino acids (EAA) and total amino acids (TAA) contents of body wall, but decreased Leu, Ile and Tyr contents. ④ Total superoxide dismutase (T-SOD) and total antioxidant capacity (T-AOC) increased with the increasing of dietary valine levels and those of D1 were significantly lower than other groups. Malondialdehyde (MDA) content decreased with increasing levels of valine up to 1.73% diet and then increased, and MDA of D4 was significantly lower than those of other groups. ⑤ Protease and lipase increased initially and then decreased, and protease of D3 was significantly higher than that of other groups, however, there was no significantly effect on amylase of dietary valine. In conclusion, appropriate dietary valine improved significantly growth performance and immune response and modified chemical composition and amino acid contents of sea cucumbers. With WGR as evaluation indicator, regression analysis of broken-line model showed that the optimum dietary valine of sea cucumber with body weight 9.20 g was 1.79% (9.18% diet protein).

Key words:Apostichopus japonicus;valine;growth performance;immune response