Prediction of apparent digestibility of hays from natural pastures of the Northeast region of Portugal

摘要

IntheNortheastregionofPortugalhaysfromnaturalpasturesaretraditionallyusedasthemainfeedduringtheperiodofdroughtandtheevaluationofitsnutritivevalueisessential.Theaimofthisstudywastopredicttheapparentorganicmatterdigestibility(OMD)of21haysfromnaturalpasturesbasedonchemicalcomposition,pepsin-cellulasesolubilityoforganicmatter(OMS)andinvitroorganicmatterdigestibility.nbsp;Chemicalcompositionofhaysshowedawiderangeofvaluesandaciddetergentlignin(ADL)wasthecomponentthatpresentedthehighestvariation(CV=18.4%).TheOMDvariedbetween516and658g/kgOM.ThebestsingleOMDpredictorwasOMS(RSD=2.8%,R2=0.52,P0.001).UsingmultipleregressiontopredictOMD,thevariablesincludedinthemodelwereOMSandADL(OMD=21.51+0.94OMS#8211;0.83ADL;RSD=2.75%;R2=0.54;P0.0001).nbsp;Accordingtoprincipalcomponentanalysis(PCA)haysweredividedin3groupsandthemultipleregressionestablishedforthelargergroupofhays(n=10)was:OMD=4.13+0.85OMS#8211;1.03ADL;RSD=2.13%,R2nbsp;=0.77,P0.0001.nbsp;TheOMSmethodwassuperiortochemicalcompositionandtotheinvitrorumenfluidmethodinpredictingOMDofhaysfromnaturalpastures.ResultsfromPCAsuggestedthatitmaybeusefultogroupthesehaysaccordingtoitschemicalcompositiontoaccuratelypredictOMD.