Effects of replacing soybean with broad bean on “in vitro” gas production using rumen fluid from sheep

摘要

Effectsoftheproteinsourceontotalgasproductionintherumenwerestudiedon4Sicilo#8211;Sarderams.Ramswere4.75years(standarddeviation(STD)=0.5year)ofageandhada53.2kgaverage(STD=6.6kg)livebodyweight.Theyhadpermanentcanulasintherumenthroughoutatwomonthexperimentalperiodandwerelodgedinindividualboxes.Animalsreceivedarationdistributedintwomealsthatincluded1.5kgdrymatterofoathay(Crudeprotein(CP):6.8%,energy:0.72UF(ForageUnit))and500g/ram/dayofoneoftwoconcentratescomparableforenergeticandnitrogencontents.ThefirstconcentratebasedonSoybean(CS)(CP:14.5%,UF:0.96)wasdistributedduringthefirstmonth.ThesecondconcentratebasedonViciaFabaL.beans(CF)(CP:14.7%,UF:0.96)wasdistributedduringasecondonemonthperiodfollowingatwoweekadaptationperiod.Totalgas(CO2andCH4)wasdeterminedonrumencontentcollectedbeforethemorningmealthatwasfilteredthroughfoursurgicalgaslayers.Ramsweredeprivedfromdrinkingwaterduringthenightbeforesamplesweretaken.Oathaywascrushedto1mmparticlesofwhich0.5gsampleswereputinto100mlplasticsyringesinadditionto10mlofrumenjuiceand40mlofartificialsaliva.EachsyringecontentwasthensplashwithCO2toletslipoxygenandclosedwithalubricatedpiston.Syringeswerethenincubatedat39°C.Gasproductionwasthenrecordeduntilaplateauswasreached.nbsp;TotalgasproductionwascomparablefortheCFandCSconcentrates(mean=53.5ml,STD=6.31mlandmean=51.8ml,STD=11.5ml,respectively),whereaspotentialgasproductionwassignificantlyhigher(p0.05)fortheCF(65.4)comparedtothatfortheCSconcentrate(26.8).EquationsmodellingthekineticofgasproductionwereYt=65.4(1-exp(-0.002t))andYt=26.8(1-exp(-0.006t))forCFandCSconcentrates,respectively.ReplacingSoybeanswithViciaFabaL.beansinSicilo-SardedietsmayincreasegasproductionintherumenprobablybecauseofViciaFabaL.beansnutritionalcharacteristicsandtheirhighstarchcontent.