Effects of treatment of rice straw with lime and/or urea on responses of growing cattle

摘要

Two3-monthfeedingtrialswereundertakentoevaluateeffectsoftreatmentsusingquicklimeand/orureaonthefeedingvalueofricestraw.InTrial1,20youngbullswereallocatedinto4groupstobefedondietsbasedonuntreatedstraw(U0L0),3%lime-treatedstraw(U0L3),4%urea-treatedstraw(U4),or3%limeplus4%urea(U4L3).Thestrawsweregivenadlibitumtogetherwithminimumsupplementationofmaize,fishmeal,mineralsandvitamins.InTrial2,15crossbreddairyheifersweredividedinto3groupstobefedadlibitumonuntreatedstraw(U0L0),3%lime-plus-2%ureastraw(U2L3)or4%ureastraw(U4),togetherwith0.5kgofacompoundconcentrateand0.4kgdrymatter(DM)ofgreengrassperheadperday.Inbothtrials,inthemiddleofeachmonthofthemainexperimentperiod,feedintakeandtotalfaecesexcretionweremeasuredandsampledfor7daystodetermineapparentdigestibility.ItwasfoundinTrial1thatstrawstreatedwith3%lime,4%ureaor3%limeplus4%ureaallbroughtaboutincreasedstraworganicmatterintake(OMI),organicmatterdigestibility(OMD)anddigestibleorganicmatterintake(DOMI).Theaveragedailygain(ADG)was74,211,280,and303ghead/dayforgrowingcattlefedonU0L0,U0L3,U4L0andU4L3,respectively.Thethreetreatmentsdramaticallyimprovedfeedconversionratio.Intrial2,U2L3wasmoreeffectivethanU4intermsofOMD,DOMI,ADG,andFCR.TheADGwas284,458,and502ghead/dayforthecrossbreddairyheifersfedonU0L0,U4L0andU2L3,respectively.nbsp;Itissuggestedthatacombinationof3%quicklimeand2%ureacanbeusedasanalternativeto4%ureafortreatmentofricestraw.