Methods of adding exogenous fibrolytic enzymes to rice (Oryza sativa L.) straw and in vitro ruminal fermentation parameters

摘要

Toevaluatetheeffectofacommercialexogenousfibrolyticenzymes(EFE)onsomeinvitroruminalfermentationparametersofricestraw(OryzasativaL.),gasproduction(3,6,9,12,16,24,36,48,60,72and96h)andapparentdigestibility(24and48h)weremeasuredontreatmentsthatincludedEFEat0.04and0.08%ondrybasis,with(Inc)orwithout(NoInc)incubationwithEFEatroomtemperaturefor24hbeforetheinvitroevaluationstarted.AcontroltreatmentwithoutEFEorincubationwasalsoincluded.IndependentlyofEFElevel,NoIncincreasedthegasproductioncomparedtocontrolat12(52.4%)and48(18.1%)h.After24hoffermentation,thegasproductionwashigherinEFE0.08%thanEFE0.04%inarangeof5.0to8.9%.InctreatmentreducedthegasproductioncomparedtoNoIncat24(33.5%)and96(12.7%)h,whilethelagtimewasreducedinEFE0.08%.InrelationtotheControl,themethodsofaddingthefibrolyticenzymesdidnotaffecttheapparentdrymatterdigestibility,whichincreasedonly0.2MJEM/kgDMinNoInc.Inconclusion,theEFEaddingincreasedthegasproductionwithoutaffectingtheapparentdrymatterdigestibilityduringthefirst48hoffermentation,whiletheincubationbeforetheinvitrofermentationreducedbothparameters,independentlyofexogenousfibrolyticenzymesaddition.