Effects of replacing roasted soya beans by broken rice and duckweed on performance of growing Tau Vang chickens confined on-station and scavenging on-farm

摘要

Twotrialswerecarriedouttodeterminetheeffectofreplacingroastedsoyabeanswithbrokenriceandduckweed(DW)indietsforgrowing(TauVang)chickens.ThefirsttrialwasdoneinconfinementattheexperimentalfarmofCanthoUniversity;thesecondwasonfarmsinLongHoavillageinascavengingsystem.Theon-stationtrialwasacompletelyrandomizeddesignwith5dietarytreatmentsand3replicates.Thecontroldietwasmixedbrokenriceandroastedsoyabeansonlynbsp;(SB100);theotherfourdietshadduckweedavailableadlibitum,withsoyabeansatlevelsofnbsp;0,25,50and75oftheSB100diet(SB0DW,SB25DW,SB50DW,SB75DW,respectively),fedtogrowingchickensfrom5to15weeksofage.Theproportionofdietaryproteincontributedbyduckweedincreasedlinearly(R2=0.96)asthecontentofsoyabeansintheconcentratewasreduced.TotalDMintakeandliveweightgainshowedapositivecurvilinearrelationshipwiththeproportionofdietaryproteinderivedfromduckweed.nbsp;DMfeedconversionwasequallyrelatedwithnbsp;theproportionofdietaryproteinderivedfromduckweed.nbsp;Optimumvalueswereobtainedwith75%replacementofnbsp;roastedsoyabeansnbsp;proteinbyduckweed.nbsp;Themeatfromchickensfedduckweedhadamoreintenseyellowcolorthanthatfrombirdsonthesoyabeanmealcontroldiet.Feedingfreshduckweedtolocalgrowingchickensresultedindecreasedfeedcostscomparedtothedietwith100%soyabeans,especiallywhen100%and75%ofthesoyabeanswasreplacedbybrokenriceandfreshduckweed.Theon-farmtrialwasacompletelyrandomizeddesignwith3treatmentsand4replications(farms).TheSB25dietnbsp;fromtheon-stationtrialwasselectedasthebasaldietandgiventoallexperimentalgroups.Therewereintotal60chickensfrom5weeksofageoneachfarmdividedinto3groupsof20.Twogroupswereallowedtoscavengeinthegardens,withorwithoutaduckweedsupplement(SCDWandSC),andonegroupwasconfined(CFDW)andgivenduckweedad-libitum.Therewerenodifferencesingrowthperformanceamongthetreatments.ThehighesteconomicbenefitswereontheSCDWdiet.