Influence of multinutrient blocks on liveweight gain of young bulls grazing sorghum stubble during the dry season

[摘要] Anexperimentwascarriedouttoevaluatetheinfluenceofmultinutrientblocks(MB)onliveweight(LW)gainofyoungbullsof235kginitialLWgrazingsorghumstubbleduringthedryseason.Thirtytwoanimalsweredividedintwogroupsofsimilarweightandcontinuouslygrazedtwopaddocksof14hafor21weeks.OnegroupwasofferedMBinfourplacesandtheotherreceivedamineralmixture(MM).Bothgroupswererotatedbetweenpaddockseverytwoweekstominimizetheeffectofplot.TheMBhad32.3%crudeprotein,andthemainingredientswere40%chickenmanure,32.5%molasses,10%lime,5%salt,5%minerals,5%ureaand2.5%groundhay.LWgainsofanimalsofferedMMandMBwere1.18and1.33kg/dayduringthefirsteightweeks(Plt;0.05)and0.30and0.31kg/dayduringtheremaining13weeks(Pgt;0.05).ThehigherresponsetoMBatthebeginningofthetrialwasassociatedwithahighavailabilityofstubbleoflownitrogencontent.ThereductionofstubbleavailabilitytowardstheendofthetriallimitedtheLWgainresponsetoMB.

[学科分类] 农业科学（综合）