Effects Of Replacement Of Dietary Fish Meal By Poultry By Product Meal And Corn Gluten Meal On Growth Performance,Biological Parameters And Intestinal Health In Turbot (Scophthalmus Maximus)

In this study,we choose turbot(Scophthalmus maximus),an important mariculture fish in China,as an experimental subject.Experiments were carried out in an indoor aquaculture tank circulation system to explore effects of replacement of dietary fish meal by the animal protein source-poultry by product meal and the plant protein source-corn gluten meal on growth performance,biological parameters and intestinal health in turbot.the contents and the results of the study are as follows:1.Effects of replacement of fish meal with poultry by product meal on growth,logical parameters and intestinal enzyme activity of turbotIn this experiment,the average weight(11.4±0.2g)of juvenile turbot was taken as the experimental subject,and the proportion of poultry by product meal was 0%,25%,37%and 50%instead of fish meal to prepare four feed treatment groups of equal nitrogen(crude protein 48%)and equal fat.The main results are as follows:Effects of replacing fish meal with poultry by product meal on the growth performance,biological parameters of turbot:With the proportion of replacing fish meal with poultry by product meal increasing,there was no significant difference in the condition factor(CF),viserosomatic index(VI),and hepatosomatic index(HSI)of turbot(P>0.05).There was no significant difference(P>0.05)between weight gain rate(WG)and specific growth rate(SGR)when the replacement ratio was 25%.However,with the increase of substitution ratio,the weight gain rate and specific growth rate of turbot decreased significantly(P<0.05),The results showed that the poultry by product meal could replace the fish meal to a certain extent.Effects of replacement of fish meal with poultry by product meal on intestinal enzyme activity of turbot:With the increase of replacement ratio of poultry by product meal,there was no significant difference(P>0.05)in the activity of Alkaline phosphatase activity(AKP),Maltase activity(MAL)and Leucine aminopeptidase(LAP)of turbot.There was no significant difference between Lysozyme(LZM)and Acid phosphatase activity ACP(P>0.005).Antioxidant enzymes activity of Superoxide dismutase activity(SOD),Calalase activity(CAT),Glutathione peroxidase activity(GPX),Inducible nitric oxide synthase activity(INOS)and Glutathione reductase activity(GR)there was no significant difference(P>0.005),and when the replacement amount was 25%in poultry by product meal,there was no significant difference in Glutathione level(GSH)content and Malondialdehyde level(MDA)(P>0.005),with the replacement ratio increases,the GSH content is a significant reduction in the energy,level of Malondialdehyde level(MDA)oxidizing index increased significantly.Results showed that the substitution of poultry by product meal for fish meal over a certain proportion had a negative effect on the enzyme activity of turbot.Effects of replacing fish meal with poultry by product meal on the intestinal structure of turbot:With the increase of poultry by product meal,Musocal folds height decreased,The Mucosal folds fusion degree was improved,with the increase of poultry by product meal,the number of intestinal epithelial cells decreased.The Submucosa width and the Submucosa cellular infiltration increased but did not produce significant effects(P>0.005).The experimental results show that the poultry by product meal can be under a certain replacement ratio(25%)to replace fish meal for turbot growth,biological parameters and intestinal health does not produce significant effect,but more than that,will be part of growing biological parameters for turbot and intestinal health and negatively impact the poultry by product meal on the turbot fish meal replacement replacement ratio can reach 25%.2.Effects of replacement of fish meal with corn gluten meal on growth,logical parameters and intestinal enzyme activity of turbotIn this experiment,the average weight(11.4±0.2g)of juvenile turbot was taken as the experimental sub.ject,and the proportion of corn gluten meal was 0%,20%,30%and 40%instead of fish meal to prepare four feed treatment groups of equal nitrogen(crude protein 48%)and equal fat.The main results are as follows:there was no significant difference(P>0.005)in the specific growth rate when the replacement ratio was 20%,With the increase of corn gluten meal substitution,the specific growth rate(SGR),feed efficiency ratio(FER),The apparent digestibility coefficients for dry matters(ADCd)and The apparent digestibility coefficients for protein(ADCp)of turbot decreased significantly(P<0.005).The results showed that the growth performance of turbot was damaged when corn gluten meal was substituted for fish meal.Effects of replacing fish meal by corn gluten meal on intestinal enzyme activity of turbot:There was no significant difference in the activity of alkaline phosphatase(AKP)between CGM20 and CGM0(P>0.005),but with the increase of zein replacement ratio,the CGM30 CGM40 group showed a significant decrease(P<0.05);There was no significant difference(P>0.005)in lysozyme(LZM),there was no significant difference(P>0.005)in Acid phosphatase activity(ACP),Complement 3(C3),Complement 4(C4)and IgM level(IGM)when the replacement ratio was 20%.Malondialdehyde level(MDA)of oxidizing index with the rising of CGM level increased significantly(P<0.005),while Superoxide dismutase activity(SOD),Catalase activity(CAT),Glutathione peroxidase activity(GPX)activity of oxidation resistance index increased with the increase of the proportion of corn gluten meal to replace fish meal show the change of significantly lower(P<0.005),Glutathione reductase activity(GR)activity there was no significant difference(P>0.005).The above results showed that the replacement of corn gluten meal for fish meal in a certain proportion did not have a significant effect on the intestinal enzyme activity of turbot,but with the increase of replacement ratio,the intestinal enzyme activity of some parts decreased significantly.Effects of replacing fish meal with corn gluten meal on the intestinal structure of turbot:there was a significant difference(P<0.05)in mucosal folds height,mucosal folds fusion,lamina propria cellular infiltration,submucosa width and Submucosa cellular infiltration in the CGM20 compared with the CGM0,There was no significant difference(P>0.05)between the CGM20 and the CGM0 in Lamina propria width.However,with the increase of replacement ratio,there was a significant difference(P<0.05)in the CGM30 and CGM40.Above experiment results show that the corn gluten meal to replace fish meal with the increase of the replacement ratio,the proportion of corn gluten meal was 20%,some biological parameters such as specific growth rate,intestinal enzyme activity such as alkaline phosphatase.There was no significant change,but the whole,corn gluten meal to replace fish meal for turbot growth,biological parameters and intestinal health and have significant negative effects.