Valorisation des pailles de cereales en alimentation des ovins dans le nord de la Tunisie: 1. Traitement aux alcalis (ammoniac/urée). 2. Complementation par des blocs melasse-uree

摘要

Thefeedingvalueofwheatstraw(WS)wasstudiedafteritstreatmentwith3.5kganhydrousammonia(ATS)orwith5kgurea(UTS)usingdifferentlevelsofwater:15(UTS15),30(UTS30)and45(UTS45)litressprayedon100kgofstraw,orwithsupplementationwithmultinutrientblocks(WSBLOCK).Fourgroupsof30adultewesAQueuefine@,allotedinto6groups(replicates)of5each,wereofferedWS(control),UTS45,ATSandWSBLOC.EwesgivenWS,UTS45andATSreceivedasupplementof100g/dbarley+minerals.Theeweswereusedtodeterminestrawandblocksintakeandtheliveweightchangeafterafeedingperiodof4months.Astudyofstrawdegradabilitywasalsoconductedon4malebarbarinrumen-fistulatedsheepfedUTS45andsupplementedwith100g/dbarley+minerals.Theresultsshowedanimprovementintotalnitrogencontent,morethanthedoubleoftheinitialvalue.Drymatterdisappearenceofstrawafternylonbagincubationfor72hwasraisedby10and12pointsrespectivelyforUTS45andATS.Theoptimaltreatmentefficiencymeasuredbytheresidualureaandstrawdegradabilitywasobtainedwithawaterlevelof45litresfor100kgofstraw.Theintakeofuntreatedstraw(WS)decreasedmarkedly(P0.05)andtherewaslossofliveweight(-2.8kg).AnimalsfedUTS45andATSshowedanincreaseof30%forstrawintakeandapositiveliveweightchangeof4and5.7kgrespectively.Multinutrientblockswereveryappetizing.Anaverageintakeof180g/d(DM)increasedstrawintakeby40%andtheliveweightgain(6.4kg)wasmarkedlyhigher(P0.05)thanobservedwithUTS45andATS.