生物絮团对罗氏沼虾体组成和消化酶活性的影响

通过向养殖水体中泼洒糖蜜构建生物絮团养殖模式,分析生物絮团营养组成,并探讨生物絮团对罗氏沼虾体组成和消化酶活性的影响。试验分对照组和试验组(生物絮团组),其中试验组在养殖过程中泼洒糖蜜。试验在室内水泥池内(2 m×2 m×0.6 m)进行,每个处理有3个重复,每个重复225尾虾(0.26 g±0.02 g),试验周期为90 d。养殖过程中不换水,糖蜜的泼洒量根据饲料投喂量进行计算(C/N为20)。结果显示:添加糖蜜能够显著促进生物絮团的形成,到第90天时,试验组的絮团体积达21.22 mL/L;而对照组为6.03 mL/L;试验组絮团粗蛋白含量为29.47%,粗脂肪含量为4.32%,二者均显著高于对照组,而粗灰分含量为11.36%,显著低于对照组;泼洒糖蜜对罗氏沼虾体组成的影响不显著,对照组和试验组肌肉粗蛋白含量分别为21.09%和21.20%,粗脂肪含量分别为2.91%和3.06%;另外,向水体中泼洒糖蜜对罗氏沼虾消化酶活性影响显著。试验组罗氏沼虾肠脂肪酶活性、胃脂肪酶活性和胰脂肪酶活性均显著高于对照组;试验组罗氏沼虾糜蛋白酶活性、胰蛋白酶活性也均显著高于对照组。但泼洒糖蜜对肠淀粉酶、胃蛋白酶、胃淀粉酶、胰淀粉酶和纤维素酶活性没有显著影响。试验表明,生物絮团营养组成丰富,能够有效提高消化酶活性。

Effects of biofloc technology on the growth and body composition of giant freshwater prawn,Macrobrachium rosenbergii

Biofloc technology is considered as a method that degrades organic waste by microorganisms and produces microbial flocs.A 90-day experiment was performed with 2 groups differentiated by bioflocs treatment and relative control in 6 indoor cement ponds, with 225 shrimps in each pond (2 m×2 m×0.6 m), to investigate the effects of bioflocs on muscle composition and digestive enzymes activity of Macrobrachium rosenbergii in zero-exchanged water system.Molasses was added to the water of experimental group ponds with the C/N ratio of 20 based on the amount of daily feed.At the end of the experiment, results indicated that molasses addition could significantly improve the formation of the floc.At the 90th day, the floc volume in the experimental group increased gradually to 21.22 ml/L, but the value in the relative control group was 6.03 ml/L.The crude protein and crude lipid of the biofloc was 29.47% and 4.32%, respectively, which was significantly higher than that in the control group.However, the ash content of the biofloc in the experimental group was 11.36%, which was significantly lower than that in the control group.Biofloc technology did not affect the muscle composition of shrimp.The content of crude protein and crude lipid of shrimp was 21.09% and 21.20%, 2.91%and 3.06%, respectively.Compared with the control group, significantly higher intestine lipase, gastric lipase, pancreatic lipase, chymotrypsin and trypsase of shrimp were found in the experimental group.However, molasses addition had no significant effect on the activities of intestinal amylase, gastric pepsin, gastric amylase, pancreatic amylase and cellulose.In conclusion, the results of the current study confirm the positive effects of biofloc on the digestive enzyme activity of M.rosenbergii.