| This study was conducted to investigate the effects of dietary anchovy autolysis hydrolysate and tuna stickwater hydrolysate in high plant diets on growth performance,physiological health and protein metabolism in yellow catfish(Pelteobagrus fulvidraco).The results are summarized as follows:1 Nutritional changes associated with the process of anchovy autolyzingTo evaluate the feasibility of anchovy hydrolysate from autolysis process for feed,four anchovy autolysis hydrolysates,which were designed as control(C),antibiotic(A),exogenous papain(E),and antibiotic and papain(E + A),were prepared at 55 ?.The hydrolysates were analyzed with free amino acid,biogenic amine,MDA,etc.The results showed that optimum time for autolysis was not exceeding 9 h with ?-amino nitrogen and total bacterial count as the evaluation index.Free amino acid,volatile basic nitrogen and cadaverine increased significantly(P<0.05)after autolyzing 9 h,and the total free amino acid was approximate 15 g/100g(dry weight).The level of histamine,putrescine,spermine,and spermidine decreased.Unsaturated fatty acid partly changed into saturated fatty acids.Acid value,MDA,and peroxide value were not significantly different from raw fish.The results suggest that anchovy protein autolyzed quickly at 55 ?.In this process,high free amino acid and low fat oxidation products were obtained.The corruption of protein and oxidation of fat during autolyzing 9 h were mainly effect by endogenous tissue enzymes rather than exogenous papain and bacterium.2 Effect of anchovy autolysis hydrolysate on growth performance and physiological health of yellow catfishThis study is amined to investigate the effect of anchovy autolysis hydrolysate on growth performance and fish health of yellow catfish.In practical yellow catfish formulation mode,a control diet containing 30% commercial anchovy fish meal was prepared.(1)A experiment diet(MPH6)with 6% of anchovy hydrolysate replace fishmeal partially was prepared.(2)Three non-fish meal diets were prepared with inclusion levels of 3%,6%,12% hydrolysate(dry matter),named FPH3,FPH6 and FPH12,respectively.The five experimental diets were isonitrogenous,isolipidic and isoenergetic.The diets were fed triplicate groups of yellow catfish [initial body weight(30.08 ± 0.35)g] for 60 days in outdoor farming system.The results showed that the SGR and FCR of FPH12 were not significantly different from FM,but SGR of MPH6,FPH3 and FPH6 decreased 15.45% to 24.39%,and FCR increased 32.14% to 42.86%.The moisture,crude protein,crude fat,and ash of whole body had no significantly difference among all treatments.A variety of free amino acids in fillet of FPH3,FPH6,FPH12 were significantly higher than those of FM.The levels of free Met and Lys in fillet were significantly associated with the inclusion in diet by Pearson correlation test.There were no significant differences of AST,ALT,HDL,LDL,TP,CHOL,and TG among all treatments.Compared to FM,the ALB of fish was significant increased fed FPH3.High histamine diets(FM and MPH6)caused gastric mucosal cell damage in yellow catfish.The results suggest that there is a certain equivalence between 12% anchovy hydrolysate and 30% fish meal on yellow catfish growth performance,feed utilization and serum biochemical indices.The levels of free amino acids in fillet,particularly flavor amino acids,were promoted by anchovy hydrolysate.3 Effect of tuna stickwater hydrolysate on growth performance and physiological health of yellow catfishTen isonitrogenous,isolipidic and isoenergetic experimental diets were carried out to investigate the effects of stickwater(SW),stickwater hydrolysate(HSW)and stickwater hydrolysate meal(HSM)on the growth performance and physiological health of yellow catfish.The control diet containing 30% fish meal and other nine non-fish meal diets were formulated with SW,HSW or HSM,supplying approximate 25%,50%,75% of fish meal protein in the control diet and named as SW25,SW50,SW75,HSW25,HSW50,HSW75,HSM25,HSM50,and HSM75,respectively.The diets were fed triplicate groups of yellow catfish [initial body weight(15.67 + 0.11)] for 60 days in outdoor tanks.Compared to FM,there were no significant differences in SCR of fish fed with 8%~16% HSW and HSM diets(P>0.05).SGR of fish fed SW diets were the poorest and reduced 18.62% ~ 43.09%(P<0.05).Decreasing tendency of fish growth performance and feed utilization were obtained when we increase the content of SW,HSW and HSM in diets.Compared to FM,no significant differences were found in protein and ash content of whole body and liver.However,fat in whole and liver of fish fed SW75 were significantly lower than those of FM and HSW25.Compared to FM,no significant differences were found in serum AST,ALT,TP,ALB,GLU,HDL,LDL,and TG.The total bilirubin in serum of fish fed SW,HSW and HSM diets were lower than FM,and increasing tendency of were obtained following the increase content of SW,HSW and HSM in diets.These results suggest that HSW is an ideal fish meal replacement,and the appropriate level in diet is approximately 8%,in which the fish had an excellent biological value and physiological health as with 30% fish meal.The lower growth performance and feed utilization were obtained by increasing the SW,HSW and HSM in diets from 8% to 23%.It may be because that high level of free amino acid in diet was negatively correlated with the growth performance of catfish.4 Effect of tuna stickwater hydrolysate peptide profile on growth performance and physiological health of yellow catfishThis study was conducted to determine how peptide profile and free amino acid content of HSW influence growth performance and physiological health.Ten isonitrogenous,isolipidic and isoenergetic experimental diets were prepared with low degree of hydrolyzed stickwater hydrolysate(L-HSW),middle degree of hydrolyzed stickwater hydrolysate(M-HSW)and high degree of hydrolyzed stickwater hydrolysate(H-HSW).The control diet containing 28% fish meal and other nine diets were formulated with L-HSW,M-HSW or H-HSW,supplying approximate 15%,30%,45% of fish meal protein in the control diet and named as L-HSW15,L-HSW30,L-HSW45,M-HSW15,M-HSW30,M-HSW45,H-HSW15,H-HSW30,and H-HSW45,respectively.The diets were fed triplicate groups of yellow catfish [initial body weight(18.67 + 0.11)] for 60 days in outdoor tanks.Compared to FM,SGR of fish fed 8% L-HSW and M-HSW showed no significant difference.Decreasing tendency of SGR were obtained when we increase the content of H-HSW in diets and H-HSW45 decreased 23.08%(P<0.05).There were no significant differences were found in protein and ash content of whole body and liver among all treatments.However,fat in whole and liver of fish fed M-HSW15 were significantly lower than those of FM.Compared to FM,no significant differences were found in AST,ALT,GLU,total bilirubin,and TG,but TP and ALB in fish fed L-HSW15 and H-HSW15 and HDL in fish fed L-HSW30 significantly reduced.The CHOL in serum of fish fed HSW diets were significantly lower than FM.These results suggest that M-HSW is an ideal fish meal replacement,and the appropriate level in diet is approximately 8%,in which the fish had an excellent biological value and physiological health as with 28% fish meal.The lower growth performance and feed utilization were obtained by increasing the H-HSW in diets from 4% to 13%.It may be because that high level of free amino acid in diet was negatively correlated with the growth performance of catfish.5 The effect of Pep T1 in yellow catfish intestinal on protein absorption.The objective of the study was to investgate the effect of stickwater hydrolysates on the expression of Pep T1 m RNA and protein absorption.Firstly,partial sequence of Pep T1 was cloned in present experiment.Then,the real-time PCR assay was used to measure the m RNA level of Pep T1 in tissues based on the result of tissue-differential expression in yellow catfish.The Pep T1 m RNA was distributed in all intestinal tissues,but the expression level in yellow catfish was mainly in the foregut and significatly higher than midgut and hindgut(P<0.05).Compared to FM,the Pep T1 m RNA expression level in fish fed with 8% SW,HSW,and HSM up-regulated significatly(P<0.05)and 12%~ 24% down-regulated significatly(P<0.05).The serum total free amino acid of fish fed SW diets were significat higher than that of FM,and an increasing tendency of serum total free amino acid were observed when we increase the content of L-HSW,M-HSW and H-HSW in diets.The results suggest that SW and HSW could affact protein absorption by regulating the expression of Pep T1 m RNA.High growth performance could be obtained in fish fed appropriate level HSW because of improving protein absorption by up-regulating Pep T1 m RNA expression.High level of SW and HSW may lead to high serum free amino acid that exceed the requirement of yellow catfish and eventually result in the low growth performance and absorption of di/tri-peptides and free amino acid by down-regulaed Pep T1 m RNA expression level. |
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