CAJ | 학술논문

选用初始体质量(3.02±0.16) g的吉富罗非鱼幼鱼(Oreochromis niloticus)450尾,随机分为5组,每组3个重复,每重复30尾实验鱼,分别饲喂添加壳寡糖质量分数为0.00%(对照组)、0.10%、0.30%、0.50%和0.70%的饲料8周,考查壳寡糖对吉富罗非鱼幼鱼生长性能、前肠组织结构及肠道主要菌群的影响.结果表明,在生长性能方面,添加0.30%、0.50%和0.70%壳寡糖组增重率分别较对照组显著提高12.53%、16.17%和9.47%(P<0.05);添加壳寡糖各组较对照组饲料系数显著降低,饲料干物质和蛋白质的表观消化率均显著升高(P<0.05).在肠道组织结构方面,与对照组相比,添加0.30%和0.50%壳寡糖组的幼鱼前肠绒毛长度显著增加了18.02%和23.21%,宽度显著增加了45.21%和54.06%,密度显著增加了15.18%和19.37%(P<0.05);添加0.30%、0.50%和0.70%壳寡糖组的幼鱼肠壁厚度较对照组分别减少了16.41%、19.96%和15.00%(P<0.05).在肠道主要菌群方面,各壳寡糖添加组大肠杆菌数量均显著降低,乳酸杆菌数量显著增加(P<0.05).上述结果表明,吉富罗非鱼幼鱼饲料中添加壳寡糖可提高其生长性能,并改善肠道内环境,推荐适宜添加量为0.30%~0.50%.
선용초시체질량(3.02±0.16) g적길부라비어유어(Oreochromis niloticus)450미,수궤분위5조,매조3개중복,매중복30미실험어,분별사위첨가각과당질량분수위0.00%(대조조)、0.10%、0.30%、0.50%화0.70%적사료8주,고사각과당대길부라비어유어생장성능、전장조직결구급장도주요균군적영향.결과표명,재생장성능방면,첨가0.30%、0.50%화0.70%각과당조증중솔분별교대조조현저제고12.53%、16.17%화9.47%(P<0.05);첨가각과당각조교대조조사료계수현저강저,사료간물질화단백질적표관소화솔균현저승고(P<0.05).재장도조직결구방면,여대조조상비,첨가0.30%화0.50%각과당조적유어전장융모장도현저증가료18.02%화23.21%,관도현저증가료45.21%화54.06%,밀도현저증가료15.18%화19.37%(P<0.05);첨가0.30%、0.50%화0.70%각과당조적유어장벽후도교대조조분별감소료16.41%、19.96%화15.00%(P<0.05).재장도주요균군방면,각각과당첨가조대장간균수량균현저강저,유산간균수량현저증가(P<0.05).상술결과표명,길부라비어유어사료중첨가각과당가제고기생장성능,병개선장도내배경,추천괄의첨가량위0.30%~0.50%.
Chitooligosaccharide (COS), which is one type of the oligosaccharides, is produced from chitin or chi-tosan by chemical or enzymatic decomposition methods. Some studies in fish regard that adding COS in dietary could produce beneficial effects on growth performance, nonspecific immune, or blood profiles. However, little information is available on its basal mechanism about which was effected by COS on promoting growth perform-ance and feed conversion, especially on intestinal microorganisms and gut mocosal structure. Therefore, we ran-domly assigned fish (N=450, average initial body weight=3.02±0.16 g) into 5 groups consisting of triplicate (n=30 fish/replicate). Each group was hand-fed a diet containing either 0 (control group), 0.10%, 0.30%, 0.50%or 0.70%COS to satiation three times daily for 8 weeks, and fish were reared in 400 L aquaria with the temperature of (27±2)℃. We measured growth, intestinal microorganisms, nutrient digestibilities, and gut mocosal structure at the end of the trial. The results were as follows: compared with the control group, weight growth rate (WGR)of fish with 0.30%, 0.50% and 0.70% COS diets increased by 12.53%, 16.17% and 9.47%(P<0.05), respectively. All groups with COS significant increases in specific growth rate (SGR) and the digestibilities of dry matter and pro-tein (P<0.05), whereas feed conversion rate(FCR)decreased significantly (P<0.05). Compared with control group, intestinal villus length was increased by 18.02% and 23.21% (P<0.05), and intestinal villus width increased by 45.21%and 54.06%(P<0.05), and intestinal villus density increased by 15.18%and 19.37%(P<0.05) by the ad-dition of COS 0.30%and 0.50%in diet. Each gradient of added COS reduce the amount of Escherichia coli, and increase the amount of Lacto bacillus of juvenile tilapia (P<0.05). Results above showed that additional COS im-proved the intestinal environment and the growth performance, therefore the appropriate addition is 0.30%~0.50%diet of juvenile GIFT tilapia.