Prediction of relative feed value of alfalfa hays harvested at different maturity stages using in vitro gas production

摘要

Inthisstudytheeffectofmaturitystageonchemicalcomposition,relativefeedvalue(RFV),drymatterdigestibility(DMD),drymatterintake(DMI)andinvitrogasproduction,ofalfalfahays(Medicagosativa)wasinvestigated.Thepotentialofgasproductiontechniquetopredictrelativefeedvalue(RFV)ofalfalfahayswasalsoevaluated.Gasproductionwasmeasuredat3,6,12,24,48,72and96hourincubationtimes.Thematurityhadasignificanteffectonchemicalcomposition,relativefeedvalueandinvitrogasproduction,ofalfalfahays.WithincreasingmaturityNDF,ADFandADLincreasedandCPcontent,RFV,DMDandDMIdecreased.ThevariationofRFVexplainedbythegasproductionrangedfrom87.6to93.0.Thegasproductionat12and24hincubationtimesexplained93.0and92.2%ofvariationofRFVrespectively.Thegasproductionconstantsquot;aquot;andquot;bquot;,aloneorincombination,explainedfrpm88to99.7%ofthevariationofRFV.Thegasproductionrateconstantquot;cquot;explainedonly16.5%ofthevariationofRFV.