Influence of microbial fermentated straw on intake and growth rate in young beef cattle

摘要

Inarecentexperimentwithyoungbeefcattle,threetypesofstrawwereused:a5%ureatreatedwheatstraw(AS),anuntreatedwheatstraw(US),andamicrobialfermentedwheatstraw(MS).ThirtySimmental-ChineseYellowcrossbeefcattle,approximately12monthsoldandweighing200kg,wererandomlyallocatedto3treatmentsandreceivedoneofthethreestrawsasbasaldiet.Adailysupplementof2.5kgconcentrate,consistingof40%cottonseedcake,40%maizeand20%wheatbranwasgiventoallanimals.Thefeedingtriallasted60daystoassessintake,live-weightgainsandfeedconversion.Faeceswerecollectedduringthelast7daystodetermineinvivoapparentdigestibility.Insaccorumendegradabilityofthestrawswasdeterminedwithrumen-fistulatedanimals.Themeanvaluesfordailyliveweightgain(calculatedfromtheregressionofliveweightontimeonexperiment)were:672,1201and1164g/dfortheuntreated,5%ureaandmicrobialtreatment,respectively.Meanvaluesforapparentdigestibilityofdietdrymatter(30%concentrate;70%straw)were:0.48,0.54and0.55,forthethreetreatmentsItappearedthatthemicrobialtreatedstrawhaspotentiallythesamefeedingvalueasstrawtreatedwithurea.Furtherstudiesareneededtoexaminethechangesinchemicalcompositioncausedbymicrobialfermentation,itseffectontherumenenvironmentandtheinteractionwitheffectsofsupplementation.