Estudio del comportamiento de vacas y búfalas gestantes en la extracción de jugo de ca?a

摘要

SixF1cattle(HolsteinxZebu)andsixbuffaloes(Murrahbreed)werecomparedassourcesofanimaltractionfortheextractionofjuicefromsugarcaneusingavertical3-rollcrusher.Eachanimalworkedfor1.5hoursdailyduringalternateweeks(oneweekworking;oneweekresting)overa6-weekperiod.Measurementsweremadeofrateofcrushingofthecane(kg/hour),juiceextractionrate(kgjuicefrom100kgcanestalk),heartandrespirationrate,rectaltemperature,bodyweightchangeandfeedintake,energyexpended,workcapacityanddistancewalked.Forreasonsbeyondthecontroloftheresearchers,thevarietyofsugarcaneavailableforcrushingwasdifferentinthetwoworkperiods.WhenthecowsworkedthecanevarietywasPuertoRico61632andforthebuffaloesitwasPOJ2878.Thelatterhasaharderrindandismoredifficulttocrush.Thusthefasterrateofcrushing(162kg/hr)observedwiththecowscomparedwiththebuffaloes(131)mayhavebeenduepartlytodifferencesbetweenthecanevarieties.However,thecowswalkedfaster(0.71vs.0.60m/second)andexerted52%morepower(0.36vs.0.24KW)thanthebuffaloes.Thepulserateofthecowshadincreasedby50%bytheendoftheworkperiodof1.5hrcomparedwith30%forthebuffaloeswhilerespirationratehaddoubledforthecowscomparedwitha44%increaseforthebuffaloes.Thebuffaloesmaintainedtheirbodyweightduringworkwhilethecowslostweight.Overallgaininbodyweightwasgreaterforthebuffaloesthanforthecows.Boththecowsandbuffaloes(thefourofeachgroupthatwerepregnantduringthecourseoftheexperiment)calvednormallyaftercompletionoftheexperiment.Despitethedeficienciesindesign(confoundingofsugarcanevarietywithanimalspecie),theresultsshowedthatintheworkofgrindingsugarcane,thebuffaloessufferedlessphysiologicalstressthanthecowsandareprobablythemoreappropriatespecieformultipurposeactivitiesinvolvingwork.