| About 30 days of feeding trials were conducted in culture systems onexamine the effect of different binders or changing process conditions on physical properties of microdietss and on growth performance, survival,and vitality of digestive enzyme of laval Turbot( Scophthatmus maximus) and Günther(Cynoglossus semilaevis Gunther),which belong onflouder fish,an impotant farmed marine species in northern China.The main contents include:1. The effects of five different types of binders, sodium alginate (SA) ,xanthan (Xan), gelatin (Gel), carrageenan (Car), konjac gum (Kon), on growth status and activity of digestive enzyme of initial weight 48.47±10.9mg ,25 DAH laval turbot(Scophthalmus maximus) were studied with the adding the starch group (Cont) and living feed (LF) as controls. Feeding trals show that the body length of fish fed with Gel group (2.66±0.1cm) was significantly higher than Xan group (2.40±0.05cm) and LF group (2.30±0.03cm) (P<0.05). The final weight of fish fed with Gel group (525.63±36.3mg) was significantly higher than Xan (379.80±25.4mg) , Car (401.80±35.7mg), Kon (432.58±32.1mg), Sta (417.26±28.6mg) and LF groups (306.19±9.4mg) (P<0.05), but has no significant difference compared with SA group (448±15.6mg) (P>0.05). On the specific growth rate, the Gel group (6.7±0.2%day-1) was significantly higher than Xan (5.9±0.2%day-1), Car (6.0±0.2%day-1), Sta (6.2±0.2%day-1) and LF groups (5.3±0.1%day-1) (P<0.05), but has no significant difference compared with SA (6.4±0.1%day-1) and Kon groups (6.3±0.3%day-1) (P>0.05). Digestive enzymes activity testing indicated that the 60-day age lavae fed with Gel group and the SA group were significantly higher than the other groups in Leucine aminopeptidase (ANP) and alkaline phosphatase (AP) Specific activity of Intestine and brush border(P<0.05). 60-day age lavae fed with LF group and Xan group were significant lower than the other groups in brush border membrane AP enzyme specific activity. Based on the experimental results(P<0.05), two types of binders, Gel and SA were suitable as the binders of microdietss for laval turbot.2. The effects of five different coating materials, zein(Zein), ethyl cellulose (EC), gelatin (Gel), stearic acid (Ste), palmitic acid (Pal) on growth status and activity of digestive enzyme of initial weight 31.35±5.28mg,28 DAH laval Günther(Cynoglossus semilaevis Gunther) were studied with commercial feeds (RQ) and living feed (LF) as controls. Feeding trals show that LF group gets best growth results. On the final weights of fish EC group (192.40±20.55mg) was no significantly difference with LF group (226.83±5.97mg) (P>0.05), but it was significantly higher than Zein group (161.31±5.42mg) and Gel group (163.66±4.57mg) (P<0.05). Ste group (166.54±8.79mg), Pal group (156.58±15.61mg) and RQ group (182.18±17.0mg) were no significantly difference with EC group (P>0.05), but they were significantly lower than LF group (P<0.05).On the fullness of laval Günther, EC group (5.22±0.56) was no significantly difference with LF group (6.21±0.23) (P>0.05), but it was significantly higher than Zein group (4.38±0.15) and Gel group (4.17±0.12) (P<0.05). Ste group (4.52±0.24), Pal group (4.25±0.42) and RQ group (4.85±0.75) were no significantly difference with EC group (P>0.05), but they were significantly lower than LF group (P<0.05). On the dry matters retentiong of microdiets, Zein group and Gel group were significantly lower than other groups(P<0.05). Digestive enzymes activity testing indicated that the58-day age lavae fed with EC group was no significantly difference with RQ group(P>0.05), significantly lower than LF Groups(P<0.05),but it was significantly higher than the other groups in Leucine aminopeptidase (ANP) of Intestine and brush border, and alkaline phosphatase (AP) specific activity of brush border(P<0.05). 60-day age lavae fed with LF group and Xan group were significant lower than the other groups in brush border membrane AP enzyme specific activity(P<0.05).Based on the experimental resluts, ethyl cellulose(EC) was suitable as the coating materials of microdiet for laval Günther.3. Two micro-bound diets were made by two different granulation processes, extrusion granulation (EG) and rotating granulation (RG), and another two microcoated diets(EGc,RGc) were made by coating stearic acid on EG and RG. The effects of the four diets on growth status and activity of digestive enzyme of laval Günther(Cynoglossus semilaevis Gunther) were studied with commercial feeds (RQ) and living feed (LF) as controls. The results show that laval Günther fed with LF group grew best. On the final weight, survival rate, fullness, and the specific growth rate(SGR), LF group was significantly higher than other groups. On the dry matters retentiong of microdiets, RG group and RQ group were no significantly differences, but they were significantly lower than EGc group and RGc group (P<0.05). On the settled speed of microdiets,RG group and RQ group were no significantly differences, but they were significantly lower other diet groups. On the Leucine aminopeptidase (ANP) of Intestine and brush border, and alkaline phosphatase (AP) specific activity of brush border, EG group, RG group and RQ group were no significantly differences, but they were significantly higher than EGc group and RGc group,and they were significantly lower than LF group. Based on the results, rotating granulation (RG) can improve the water stability and Suspension of microdiets and Coating process can improve the water stability of feed,but In 28 days of Günther , the substitution of living food with microdiets made poor survival and growth. |
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