| In order to reduce the cost of feed, and reduce fish oil consumption in feed industry, Thepresent study was performed to investigate the feasibility of dietary substitution of fish oil bypalm oil with different proportions in Cynoglossus semilaevis. Gowth, physiology andbiochemistry, histology and muscle nutritional quality were measured. The lipid content inthe bait was fixed at10%, and then designed palm oil (P) and fish oil ratio of10:0(10P),8:2(8P2F),6:4(6P4F),4:6(4P6F),2:8(2P8F),0:10(10F). Made six kinds of test bait andcontinuously feed C. semilaevis (initial weight19.45±1.29g)56d, and then sampled,measured growth, blood, immunizy, nutritional components of fish body, muscle aminoacids(AA), fatty acids and histopathological were determined.The result can be summarized as follows:1. There was no difference between indexes such as feed efficiency, protein utilization, HIS,relative fatness (P>0.05), The daily rate of weight gain and weight gain rate of4F6P groupwas significantly higher than10P,10F group (P <0.05), compared group4F6P with2F8P,6F4P and8F2P, there was no significant difference between them(P>0.05). Using the growthrate as an evaluation index,60percent palm oil replace fish oil get the maximal value. Therewas no significant difference between the groups of RBC, WBC, and PCV in C. semilaevisblood. The nutritional indicators of C. semilaevis body had no significantly between thegroups (P>0.05). There was no significant difference between the groups of SOD activity inserum and liver (P＞0.05). The GSH-Px activity of serum and liver in10P group wassignificantly lower than that in the10Fgroup(P＜0.05). The quadratic regression analysisresult shows that GSH-Px activity can get the maximum when use32%palm oil substitutionof fish oil. The GSH-Px activity group10F higher than group10P,6F4P,4F6P in liver, theother groups was no significant except group10F. The CAT activity have a rising tend afterfirst decreased in serum. The CAT activity get the maximum when use40%palm oil replacefish oil,, significantly higher than the other groups(P＜0.05). There was no significantdifferences between the groups in liver (P＞0.05). There was no significant between thegroups of the content MDA in serum. The content of MDA of group10P was significantlyhigher than the other groups in liver (P＜0.05). The LDL-C, CHO, GLU content of serumand the activity of surface mucus antibacterial was not significant (P>0.05) in every group.The LZM activity of surface mucus, in group10P was significantly lower than that in4P6F and10F group (P<0.05), compared with8P2F group,6P4F group and2P8F group, the group10P had no significant difference with them (P>0.05). The LZM activity had no significantdifferences between other groups (P>0.05) expect group10P. The serum AKP activity ofgroup10P was significantly higher than10F (P<0.05). The liver AKP activity of10F wassignificantly higher than the other groups (P<0.05). The serum ALT and AST activity of liverhad no significant differences between groups (P>0.05). The content of TP in liver had nosignificant differences between the groups (P>0.05).3. The result of the organizational structure of C. semilaevis, showed that the structure of liverare relatively complete in each group,which indicate that fish oil can substituted palm oil, in10P group liver sinusoid bleeding, the result indicate complete with palm oil substitute fishoil will cause fish liver and pancreas tissue lesions. Moreover, the liver, pancreas andintestinal muscle biopsy of C. semilaevis had no significant difference between groups except10P.4. There was no significant difference among six groups(P＞0.05). Seventeen amino acidswere detected except tryptophan in muscle (tryptophan was not detected). The percentage ofthe amino acids accounts for total dry matter were37.53%(10P),45.89%(8P2F),43.79%(6P4F),44.47%(4P6F),44.29(2P8F),45.25%(10F), respectively. The10P group wassignificantly lower than the other groups(P＜0.05). The percentage of nine kinds essentialamino acids (EAA) were42.15-45.22%. With the added amount of palm oil, the amount ofEAA showed a downward trend after the first rise,6P4F group was the highest. Thepercentage of four kinds delicious amino acids in muscle were36.54-41.59%,10P group isthe lowest. We detected22kinds of fatty acids in muscle. Saturated fatty acid(SFA) wereeight kinds, and no significant differences between the groups(P＞0.05),6P4F group washighest(39.62%); Monounsaturated fatty acid(MUFA) were six kinds,10P (36.34%)groupwas significantly higher than the others(P＜0.05); Polyunsaturated fatty acids（PUFA）wereeight kinds,10P group was significantly lower than the others(P＜0.05). With the addedamount of palm oil, the content of SFA and MUFA showed downward after the upward trend,the amount of PUFA showed decreased gradually, the amount of DHA4P6F group wassignificantly higher than the others(P＜0.05). The results showed that palm completelyreplace fish oil significantly reduces the nutritional quality of C. semilaevis. The fish muscleessential acids acids index(EAAI) get maxium when use44percent palm oil replace fish oil. The fish muscle PUFA and n-3PUFA get maxium when use35percent and33percent palmoil to replace fish oil.In summary, the quality of the fish muscle can be significantly improvedwhen use33-44percent palm oil to replace fish oil.Conclusion: Considering of growth, physiology and muscle nutritional quality of the fish.The lipid content in the bait was fixed at10pertent, the appropriate palm oil level was32-60pertent to replace fish oil. If the conclusion be applied in artificial bait, it can be saved intoabout178-334RMB per ton. |
PDF Full Text Request