?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=Optimal+decisions+in+organic+steer+production+-+a+model+including+winter+feed+level%2C+grazing+strategy+and+slaughtering+policy&rft.creator=Nielsen%2C+Dr.+B.K.&rft.creator=Kristensen%2C+Dr.+A.R.&rft.creator=Thamsborg%2C+Professor+S.M.&rft.subject=+Production+systems&rft.description=Organic+steer+production+demand+several+decisions+concerning+grazing+strategy%2C+feeding+level+in+the+winter+and+factors+as+slaughter+weight+and+length+of+the+fattening+period.+The+production+system+can+be+difficult+to+optimise%2C+therefore+the+objective+of+this+study+was+to+develop+a+model+to+optimise+the+grazing+strategy%2C+feed+level+in+winter+and+time+of+fattening+and+slaughter+in+organic+steer+production+with+regard+to+economic+output+at+steer+level.+The+steer+model+is+a+4-level+hierarchical+Markov+process+with+decisions+defined+at+three+levels.+Decisions+taken+in+the+model+include+grazing+strategy+(permanent+or+ryegrass%2Fclover+pasture)%2C+feed+level+in+winter+(high+and+low)%2C+time+for+beginning+of+fattening+(age+19-27+months)+and+time+of+slaughter+(age+19-30+months).+Overall+optimal+strategies+at+child+level+1+with+regard+to+economic+output+per+produced+steer+were+low+feeding+level+in+the+winter+period%2C+grazing+on+permanent+pastures+in+the+first+grazing+season%2C+whereas+ryegrass%2Fclover+pastures+gives+the+optimal+net+return+per+steer+in+the+second+and+third+grazing+season.+The+optimal+strategies+from+the+model+suggested+that+the+effect+of+fattening+in+steer+production+might+be+overstated.+It+was+concluded+that+the+natural+well-defined+phases+in+organic+steer+production+are+well+suited+to+be+analysed+by+a+multi-level+hierarchic+Markov+processes.&rft.date=2003&rft.type=Journal+paper&rft.type=NonPeerReviewed&rft.format=source&rft.identifier=http%3A%2F%2Forgprints.org%2F1871%2F1%2Foptimal_decisions.doc&rft.identifier=Nielsen%2C+Dr.+B.K.%3B+Kristensen%2C+Dr.+A.R.+and+Thamsborg%2C+Professor+S.M.+(2003)+Optimal+decisions+in+organic+steer+production+-+a+model+including+winter+feed+level%2C+grazing+strategy+and+slaughtering+policy.+Livestock+Production+Science.+[+Unpublished%2C+]&rft.relation=http%3A%2F%2Forgprints.org%2F1871%2F