Study on the use of algae as a substitute for oil cake for growing calves

[摘要] Thepossibilityofusingunicellularalgae(ChlorellaandScenedesmus)asfeedforcattlehasbeenstudied.Mixedalgalculturewasgrowninashallowpolythene-linedpondandgavearecordeddailyyieldof95tonnesofalgalsuspension(packedcellvolume5-10ml/litre)or247kgdrysubstancesperhectare.Thecostwasabout$1.25(Tk.50)pertonneofalgalsuspensionproduction.Driedalgalcellscontained613gcrudeprotein(Nx6.25)and155gfibreperkgDM.Ina120dfeedingtrial8growingcattle(7femalesand1male),ofindigenousbreedwithmeaninitialliveweightkg146quot;9kg,werefedadlibitumurea-molasses-strawand2kg/dwheatbranasbasaldiet.Thetreatmentswere0.5kg/dTil(sesame)oilcakeperheadingroupIandadlibitumalgalsuspensioningroupII.Thesuspensionwasdrunkat10%ofanimalliveweight.Theseanimalsreceivednootherliquid(water).Inclusionofalgalsuspensiondidnotimprovetotalmetabolizableenergy(ME)orcrudeprotein(Nx6.25)intakebutincreaseddailygain,althoughinsignificantly(Pgt;0.05)from399gfortheoilcaketreatmentto458ginthealgaegroup.Thefeedconversionefficiencieswere6.2and7.4gliveweightgainperMJMEintakefortheoilcakeandalgaegroups,respectively.Crudefibredigestibilitywassignificantly(Plt;0.01)higherinthealgae(81.1%)thantheoilcakegroup(76.2%).Forthe120dfeedingtrial,theestimatedneteconomiclosswas$5.0(Tk.200)/animalonoilcakewhiletherewasa$14.4(Tk.576)profit/animalonalgae.Beingasimpleproductiontechniqueoflowcostandenvironmentallyfriendly,thepresentresultsjustifymoreworkonthesubject.

[学科分类] 农业科学（综合）