饲料添加β-1,3-葡聚糖对凡纳滨对虾生长性能、血清代谢、免疫相关基因表达和抗亚硝酸氮应激能力的影响

实验旨在研究β-1,3-葡聚糖的不同投喂方式对凡纳滨对虾(Litopenaeus vannamei)生长、血清代谢和抗亚硝酸氮应激能力的影响。选用480尾初体重(0.43±0.01) g的凡纳滨对虾, 随机分为4组, 即G0(全程投喂基础饲料)、G1组(全程投喂0.1%β-1,3-葡聚糖饲料)、G2组(0.1% β-1,3-葡聚糖饲料7d+基础饲料7d循环)和G3组(0.1% β-1,3-葡聚糖饲料14d+基础饲料14d循环)。在养殖84d后, 应用亚硝酸钠进行120h亚硝酸氮应激实验。结果显示, 各实验组凡纳滨对虾生长性能和全虾营养成分没有显著性差异。在养殖84d后, G2和G3组凡纳滨对虾肝胰腺脂肪酶活性显著高于G0和G1组(P<0.05), G1、G2和G3组凡纳滨对虾血清胆固醇和甘油三酯含量显著高于G0组(P<0.05), G3组凡纳滨对虾肌肉脂多糖/?-1,3-葡聚糖结合蛋白(LGBP)、酚氧化物酶原(proPO)和超氧化物歧化酶(SOD)mRNA表达显著高于G0和G1组(P<0.05)。亚硝酸氮应激120h, G1、G2和G3组凡纳滨对虾累计死亡率显著低于G0组(P<0.05), G3组凡纳滨对虾累计死亡率显著低于G0、G1和G2组(P<0.05)。在亚硝酸氮应激120h后, 与G0组相比, G1、G2和G3组凡纳滨对虾血清总蛋白含量显著升高(P<0.05), 葡萄糖含量、谷丙转氨酶和谷草转氨酶活性显著降低(P<0.05); G3组凡纳滨对虾肌肉LGBP、proPO和SOD mRNA表达显著高于G0 (P<0.05), G1组凡纳滨对虾肌肉丝氨酸蛋白酶(SP)mRNA表达显著高于G0、G2和G3组(P<0.05)。结果表明, 14d间隔投喂0.1% β-1,3-葡聚糖可能通过促进能量代谢和LGBP、proPO和SOD mRNA表达提高凡纳滨对虾抗亚硝酸氮应激能力。

EFFECTS OF DIETARY β-1,3-GLUCAN ON GROWTH PERFORMANCE,SERUM METABOLITE,IMMUNE-RELATED GENE EXPRESSION AND RESISTANCE TO NITRITE STRESS IN LITOPENAEUS VANNAMEI

To investigate the effects of dietary β-1,3-glucan on growth performance, serum metabolite, immune-related gene and resistance to nitrite stress in Litopenaeus vannamei, 0.1% β-1,3-Glucan was supplemented to a basal diet (control, G0) with different feeding schedules: permanently β-1,3-glucan diet (G1), 7 days β-1,3 glucan diet-7 days of control diet (G2) and 14 days β-1,3 glucan diet-14 days of control diet (G3). After the feeding trial, these shrimps were exposed to nitrite-N (20 mg/L) for 120h. The results showed that dietary β-1,3-glucan had no significant effect on growth performance and whole-body composition after 84d feeding trial (P>0.05). The activity of lipase in hepatopancreas in G2 and G3 groups was significantly higher than that in G0 and G1 groups (P<0.05). The shrimp in G1, G2 and G3 groups had significantly higher hemolymph triacylglycerols and cholesterol levels than G0 group (P<0.05). Higher expression levels of LPS/b-glucan binding protein (LGBP), Prophenoloxidase (proPO) and superoxide dismutase (SOD) were observed in G3 group compared to G0 and G1 groups (P<0.05). After 120h nitrite-N stress, the mortality in G3 group was significantly lower than that of G0, G1 and G2 groups (P<0.05). Nitrite stress significantly reduced the levels of GLU, GOT and GPT and significantly enhanced hemolymph level. G3 group had significantly higher expression levels of LGBP, proPO and SOD compared to G0 group (P<0.05). The expression level of serine proteinase in G1 group was significantly higher than that in G0, G2 and G3 groups (P<0.05). L. vannamei fed diet G3 can improve nitrite resistance probably by accelerating energy metabolism and increasing expression levels of LGBP, proPO and SOD.