Effects Of Fish Meal Replacement By Three Protein Sources With Different Processing Methods On Physical Pellet Quality And Growth Performance Of Pacific White Shrimp(Litopenaeus Vannamei)

The insufficient supply and rising price of fish meal restrict the development of aquaculture industry,so it is inevitable to use other protein sources to replace fish meal.In the present study,cottonseed protein concentrate,defatted Tenebrio molitor and Clostridium autoethanogenum protein were used to replace dietary fish meal for pelleting and extruding to investigate the effects on feed physical quality and growth,feed utilization,intestine and hepatopancreas histology of Pacific white shrimp(Litopenaeus vannamei).The results will guide the application of new protein sources in shrimp feed industry.1 Effects of replacing fish meal with three protein sources on the physical quality of shrimp diet and the optimization of processing parametersThis study was conducted to investigate the effects of cottonseed protein concentrate(CPC),defatted Tenebrio molitor(TM)and Clostridium autoethanogenum protein(CAP)substituting fish meal on physical quality and to optimize corresponding technological parameters.A control diet with fish meal content of 200 g/kg was designed,then different grinding sizes(40,60,80 and 100 mesh)and post-cooking temperatures(85 ℃,90 ℃,95 ℃ and 100 ℃)were conducted to replace 100 g/kg and200 g/kg fish meal with CPC,TM and CAP,respectively,to investigate the effects on physical quality of extruded feed.In another experiment,the conditioning time was increased from 3 min to 5 min,and the post-cooking time was increased from 25 min to 50 min,respectively,to investigate the effects on the physical quality of pelleted feed.The results showed as follows :(1)The bulk density and durability index of extruded feed with 100 mesh were significantly higher than those with 40 and 60 mesh(P<0.05).The dissolution loss was the lowest when the particle size was 80 mesh(P<0.05).(2)When the post-cooking temperature was 100 ℃,the hardness and water resistance of extruded feed were significantly higher than that at the post-cookring temperature of85 ℃ and 90 ℃(P<0.05),and showed no significant difference with the feed at the post-cooking temperature of 95 ℃(P>0.05).(3)When 100 g/kg and 200 g/kg fish meal were replaced by the equal amount of CPC and TM,and the dissolution loss of extruded feeds were significantly increased(P<0.05).Dietary CPC improved the feed hardness(P<0.05),while dietary CAP decreased feed hardness(P<0.05)and showed no significant effect on feed dissolution loss(P>0.05).(4)In pelleted feed,the inclusion of CPC increased the hardness(P<0.05),but did not affect the dissolution loss(P>0.05),while dietary TM and CAP increased the dissolution loss(P<0.05).Prolonging the conditioning time and post-cooking time decreased the dissolution loss of pelleted feeds(P<0.05).In conclusion,the suitable processing parameters are fineness of 80 mesh and post-cooking temperature of 95-100 ℃.Prolonging the conditioning time and post cooking time can improve the physical quality of pelleted feed when dietary fishmeal was partially replaced by CPC,TM or CAP.2 Effects of replacing fish meal with three protein sources on physical quality of pelleted feed and extruded feedThis experiment was conducted to investigate the effects of cottonseed protein concentrate(CPC),defatted Tenebrio molitor(TM)and Clostridium autoethanogenum protein(CAP)substituting fish meal on the physical quality of pelleted feed and extruded feed.A control diet with fish meal content of 200 g/kg was designed,then,60g/kg fish meal was replaced by the same amount of CPC,TM and CAP,respectively to form eight diets,which were produced by pelleting(P)(P-FM,P-CPC,P-TM and PCAP)or by extruding(E)(E-FM,E-CPC,E-TM and E-CAP).In pelleted feeds,the hardness and bulk density were significantly increased(P<0.05),when fish meal was substituted by CPC,TM and CAP,but no significant differences in starch gelatinization degree and durability index were detected among the four diets(P>0.05).In addition,the dissolution loss and powder content in P-CPC and P-CAP groups were significantly decreased(P<0.05).In extruded feeds,the replacement of fish meal with 60 g/kg CPC,TM and CAP significantly decreased feed hardness and bulk density(P<0.05),and increased starch gelatinization degree(P<0.05),among which E-CPC group had the highest starch gelatinization degree(93.36%).There were no significant differences in durability index and powder content among all the four groups(P>0.05),and the dissolution loss in E-CAP group was significantly decreased(P<0.05).Compared to pelleted feeds,extruded feeds showed lower hardness,powder content and higher durability index,starch gelatinization degree(P<0.05),but there was no significant difference in dissolution loss between the two diets(P>0.05).In conclusion,in a diet containing 200 g/kg fish meal,the replacement of 60 g/kg fish meal with CPC,TM and CAP can improve the physical quality of pelleted feed,increase the starch gelatinization degree of extruded feed,but decreased the hardness and bulk density of extruded feed.Compared with pelleted feed,extruded feed showed lower hardness,powder content,and higher durability index(P<0.05).3 Effects of fish meal replacement by three protein sources with different processing methods on growth and nutrient utilization of Pacific white shrimp(Litopenaeus vannamei)This experiment was conducted to investigate the effects of replacing fish meal with cottonseed protein concentrate(CPC),defatted Tenebrio molitor(TM)and Clostridium autoethanogenum protein(CAP)in pelleted feed and extruded feed on growth,feed utilization,activities of digestive enzymes and protein metabolism-related enzymes,hepatopancreas and intestinal histology of Pacific white shrimp(Litopenaeus vannamei).A control diet with fish meal(FM)content of 200 g/kg was designed,then,60 g/kg CPC,TM and CAP were used to replace the same amount of fish meal to form another three formulas,respectively.Then,two processing methods,pelleting(P)and extruding(E),as well as the above four formulas,were used to produce eight diets as P-FM,P-CPC,P-TM,P-CAP and E-FM,E-CPC,E-TM,E-CAP,respectively.The eight diets were fed to shrimp with initial body weight of(7.7±0.1g)for 6 weeks.In pelleted groups,compared to P-FM group,P-TM group presented significantly higher feed conversion ratio(FCR)and lower protein retention(P<0.05),but the other two groups showed no significant differences in growth performance(P>0.05).Hepatopancreas amylase activity in P-CPC and P-CAP groups was significantly higher than that in PFM group(P<0.05),no significant differences in the activities of hepatopancreas protease and pyruvate kinase,aspartate aminotransferase and alanine aminotransferase were found among the four groups(P>0.05).The hepatopancreas and intestinal histology were normal in all groups without obvious injury.In extruded groups,compared to E-FM group,FCR in E-CPC group was significantly decreased(P<0.05),protein retention and the hepatopancreas amylase activities was significantly increased(P<0.05).but no significant differences in hepatopancreas protease activities and protein metabolism-related enzyme activities were found.The hepatopancreas protease and amylase activities in E-CAP group were significantly increased(P<0.05),the growth performance,feed utilization,body composition and protein metabolism-related enzyme activities showed no significant differences(P>0.05),the hepatopancreas and intestinal histology were normal in E-CPC and E-CAP groups without obvious injury.In E-TM group,the growth performance,feed utilization,body lipid content and pyruvate kinase activity were significantly lower than those in E-FM group(P<0.05),and this group was also observed some damage in hepatopancreas histology.When comparing pelleted groups and extruded groups,no significant differences were found in growth,nutrients utilization,digestive enzyme activity,protein metabolism and glucosemetabolism related enzyme activities(P>0.05).In conclusion,in pelleted feed or extruded feed containing 200 g/kg fish meal,the replacement of 60 g/kg fish meal with CPC and CAP had no negative effects on growth performance and nutrient utilization,but the replacement of 60 g/kg fish meal with TM decreased the growth performance and nutrient utilization of Pacific white shrimp.The shrimp fed with pelleted feeds or extruded feeds showed the similar growth performance and nutrient utilization.