枸杞多糖对尼罗罗非鱼生长发育、消化酶活性及肠道组织形态的影响

Effects of Lycium barbarum polysaccharides on growth, digestive enzyme activity and intestinal tissue morphology of Nile tilapia(Oreochromis niloticus)

  • 摘要: 【目的】明确枸杞多糖对罗非鱼机体生长发育及消化功能的影响,为罗非鱼健康养殖提供理论参考,同时为促进罗非鱼养殖产业的可持续健康发展提供新思路。【方法】在尼罗罗非鱼基础饲料中添加5个不同剂量(0~2000 mg/kg)的枸杞多糖,进行40 d的养殖试验后测量尼罗罗非鱼的体重及全长,计算相对增重率(WG)、相对增长率(LG)、特定生长率(SGR)和饲料系数(FCR),采用ELISA试剂盒分别检测淀粉酶(Amylase)、蛋白酶(Protease)及脂肪酶(Lipase)活性,并采集前肠、中肠和后肠组织制作切片,通过光学显微镜观察肠道组织形态的变化特征。【结果】于基础饲料中添加不同剂量枸杞多糖对尼罗罗非鱼的生长发育均起促进作用,其中以添加1500 mg/kg处理组的促进效果最佳,至养殖试验结束时尼罗罗非鱼的终末全长、终末体重、WG、LG和SGR均达最高值,分别为13.45 cm、48.74 g、6.96%、0.94%和5.19%/d;而FCR最小,仅为1.88。尼罗罗非鱼中肠组织的蛋白酶和淀粉酶活性在1500 mg/kg处理组中显著升高(P<0.05,下同),胃组织的蛋白酶和淀粉酶活性、肝脏组织的脂肪酶活性也是以1500 mg/kg处理组最高,但与对照组(0 mg/kg)相比无显著差异(P>0.05)。肠绒毛长度在尼罗罗非鱼前肠组织中以1500 mg/kg处理组的最短(0.351 mm)、在后肠组织中则以1500 mg/kg处理组的最长(0.320 mm),与对照组(0 mg/kg)相比差异显著;肌层厚度在前肠和中肠组织中均以500 mg/kg处理组的最厚,分别为0.089和0.087 mm,在后肠组织中则以1000 mg/kg处理组的最薄(0.065 mm)、2000 mg/kg处理组的最厚(0.099 mm)。【结论】枸杞多糖可提高罗非鱼的消化酶活性,改善其肠道组织形态,从而影响罗非鱼的生长发育,且以添加剂量为1500 mg/kg的效果最佳。

     

    Abstract: 【Objective】This study clarified the effects of Lycium barbarum polysaccharide(LBP) on the growth,development and digestive function of tilapia. The research results provided theoretical reference for healthy tilapia aquaculture and new ideas for promoting the sustainable and healthy development of tilapia aquaculture industry.【Method】Five different doses(0-2000 mg/kg) of LBP were added to the basic feed of Nile tilapia for a 40-day breeding experiment. After the experiment,the body weight and full length of Nile tilapia were measured to calculated the relative weight gain rate(WG),relative growth rate(LG),specific growth rate(SGR) and feed coefficient(FCR). ELISA kits were used to detect the activities of amylase,protease and lipase. The foregut,midgut and hindgut tissue sections of the experimental fish were prepared to observe the changes of intestinal tissue morphology.【Result】Adding different doses of LBP to the food could promote the growth and development of Nile tilapia. The group supplemented with 1500 mg/kg had the best promo-ting effect,and the final full length,final body weight,WG,LG and SGR reached the highest,which were 13.45 cm,48.74 g,6.96%,0.94% and 5.19%/d,respectively. FCR was the smallest,only 1.88. The activities of protease and amylase in midgut tissue significantly increased in 1500 mg/kg treatment group(P<0.05,the same below). The activities of protease and amylase in stomach tissue activities of lipase in liver tissue were also the highest in 1500 mg/kg treatment group. The However, there was no significant difference compared with the control group(0 mg/kg) (P>0.05). The villus length of the foregut tissue was the shortest(0.351 mm) and the villus length of the hindgut tissue was the longest(0.320 mm) in the 1500 mg/kg treatment group,representing significante difference compared with the control group(0 mg/kg). The muscle layer thickness in the foregut and midgut tissues were the thickest in the 500 mg/kg treatment group,at 0.089 and 0.087 mm,respectively. The muscle layer thickness of hindgut tissue was the thinnest(0.065 mm) in the 1000 mg/kg treatment group,and was the thickest(0.099 mm) in the 2000 mg/kg treatment group.【Conclusion】LBP can promote the growth and development of Nile tilapia by increasing the activity of digestive enzymes and improving the morphology of intestinal tissue. Adding 1500 mg/kg LBP to the feed has the best effect.

     

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