Oxalate content of different taro cultivars grown in central Viet Nam and the effect of simple processing methods on the oxalate concentration of the processed forages

摘要

TaroleavesandpetiolesarewidelyusedasanimalfeedinVietNamastheyprovidevaluablenutrients.nbsp;Thepetiolesandleavesalsocontainoxalateswhichmayhaveanadverseeffectontheanimals#8217;metabolismbybindingtocalciumandmakingitunavailableforabsorption.Thisstudyinvestigatedthetotal,solubleandinsolubleoxalatecontentsoftheleavesofpetiolesandleavesofdifferentcultivarsoftarogrownintwodifferentenvironmentsinsandysoilandlowlandincentralVietNam,andsubjectedtodifferentmethodsofprocessing.Thetotaloxalateinpetiolesrangedfrom2404to4416mg/100gdrymatter(DM)whilethelevelsintheleavesrangedfrom2021to6342mg/100gDM.nbsp;Levelsofsolubleoxalateinthepetiolesrangedfrom142to2794mg/100gDMwhilethelevelsintheleavesrangedfrom83to1475mg/100gDM.Insolubleoxalatelevelswerehigherthanforsolubleoxalateandrangedfrom961to6259mg/100gDMintheleavesandinthepetiolesfrom811to3613mg/100gDM.Therewerenodifferencesinthetotal,solubleandinsolubleoxalateconcentrationintaroforagesgrowninlowlandandsandysoil.nbsp;Cookingwasthemosteffectivemethodtoreducethesolubleoxalatecontentinpetioles(by57%)whileensilingthecombinedleavesandpetiolesreducedoxalateby37%.Washingorwiltingtheleavesreducedthesolubleoxalatecontentby9.2and14.2%,respectively.Furtherstudiesareneededtoclarifywhatdegreetheoxalatecontent,andtheeffectofensiling,oftarofoliagehasontheavailabilityofcalciumtoanimalsconsuminghighlevelsofthisfeedresource.