简介：Thisstudywasconductedtoevaluatetheeffectsofplant/animal(P/A)proteinratios(viz.1∶4,1∶3,1∶2,1∶1,2∶1,3∶1,4∶1)ongrowthperformance,bodycomposition,apparentdigestibilityofdiets,andnonspecificimmunityofjuvenileseacucumber(Apostichopusjaponicus).Seacucumbersweredividedinto21plastictanks,andeachtankwasstockedwith15individuals(initialweight:about23.73g).Eachfeedwasallocatedtothreereplicatesofseacucumbers.Thefeedingexperimentlastedfor50days.Resultsindicatedthatweightgainrate(WGR)andbodywallweight(BWW)significantlyincreasedasdietaryratioofP/Aincreasedfrom1∶4to3∶1,andthendecreasedsignificantlywithfurtherincreaseofthisratio(P<0.05).Thebodywallcoefficient(BWC)showedasimilartendencytoWGRandBWW,butnosignificancewasdetectedamongdietarytreatments(P>0.05).Theapparentdigestibilityofdrymatter,proteinandlipidincreasedwithratioofP/Aincreasingfrom1∶14to2∶1(P<0.05),andthendecreasedwithfurtherincreaseofthisratio.Correspondingly,activitiesoftrypsinandamylaseweresignificantlyincreasedasP/Aincreasedfrom1∶4to2∶1(P<0.05).TheactivitiesofSODandCATshowedasimilartrendwithWGR,withthehighestvalueobservedintheratioof1∶2and1∶1,respectively.ResultsaboveshowedthatmoderateorrelativelyhigherratioofP/Aprotein(1∶1-3∶1)significantlyincreasedthegrowthperformance,apparentdigestibility,andnonspecificimmunityofseacucumber.Thiswillcontributetoimprovingthefeedformulationforjuvenilecucumbers.