Effect of brewers’ grains and rice distillers’ byproduct on methane production in an in vitro rumen fermentation using ensiled or fermented cassava root (Manihot esculenta, Cranz) as energy substrate

摘要

Aninvitrorumenincubationwascarriedouttostudyeffectsonmethaneproductionwhen:(i)cassavarootwasfermentedwithyeast,ureaanddi-ammoniumphosphate(DAP)comparedwithfirstensilingtherootandthenaddingthesupplements;and(ii)brewers#8217;grainsorrice-winedistillers'byproductwereaddedtothesubstrateatlowlevels(4%ofthesubstrateDM).Thetreatmentswerearrangedina2*3factorialwith4replications.Alltreatmentscontainedcassavaleafmeal(30%ofsubstrateDM)andsulphur-richminerals(1%).Gasproductionandproportionofmethaneinthegaswererecordedatintervalsoverthe48hincubation.Fermentingcassavarootwithyeast,ureaandDAPincreasedthetrueproteincontentfrom1.8to7.6%inDM.Gasproductionwaslowerforfermentedthanensiledcassavarootbutwasincreasedbysupplementationwithbrewers#8217;grainsandricedistillers#8217;byproduct.Theconcentrationofmethaneinthegasincreasedwiththedurationoftheincubationandwaslowerforthefermentedratherthantheensiledcassavaroot.TheDMmineralizedduringtheincubationwaslessforthefermentedthantheensiledcassavarootbutwasnotaffectedbysupplementationwithbrewers#8217;grainsorricedistillers#8217;byproduct.MethaneproductionperunitsubstrateDMfermentedwaslessforthefermentedcomparedwiththeensiledrootandwasreducedbysupplementationwithbrewers#8217;grainsandricedistillers#8217;byproduct.