?url_ver=Z39.88-2004&rft_id=10.3168%2Fjds.2016-12189&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.relation=https%3A%2F%2Forgprints.org%2Fid%2Feprint%2F32819%2F&rft.title=The+use+of+mid-infrared+spectrometry+to+estimate+the+ration+composition+of+lactating+dairy+cows&rft.creator=Klaffenb%C3%B6ck%2C+M.&rft.creator=Steinwidder%2C+Andreas&rft.creator=Fasching%2C+C.&rft.creator=Terler%2C+G.&rft.creator=Gruber%2C+L.&rft.creator=M%C3%A9sz%C3%A1ros%2C+G.&rft.creator=S%C3%B6lkner%2C+J.&rft.subject=+Dairy+cattle&rft.description=The+composition+of+cow+milk+is+strongly+affected+by+the+feeding+regimen.+Because+milk+components+are+routinely+determined+using+mid-infrared+(MIR)+spectrometry%2C+MIR+spectra+could+also+be+used+to+estimate+an+animal%E2%80%99s+ration+composition.+The+objective+of+this+study+was+to+determine+whether+and+how+well+amounts+of+dry+matter+intake+and+the+proportions+of+concentrates%2C+hay%2C+grass+silage%2C+maize+silage%2C+and+pasture+in+the+total+ration+can+be+estimated+using+MIR+spectra+at+an+individual+animal+level.+A+total+of+10%2C200+milk+samples+and+sets+of+feed+intake+data+were+collected+from+90+dairy+cows+at+2+experimental+farms+of+the+Agricultural+Research+and+Education+Centre+in+Raumberg-Gumpenstein%2C+Austria.+For+each+run+of+analysis%2C+the+data+set+was+split+into+a+calibration+and+a+validation+data+set+in+a+40%3A60+ratio.+Estimated+ration+compositions+were+calculated+using+a+partial+least+squares+regression+and+then+compared+with+the+respective+observed+ration+compositions.+In+separate+analyses%2C+the+factors+milk+yield+and+concentrate+intake+were+included+as+additional+predictors.+To+evaluate+accuracy%2C+the+coefficient+of+determination+(R2)+and+ratio+to+performance+deviation+were+used.+The+highest+R2+values+(for+kg+of+dry+matter+intake%2F+for+%25+of+ration)+for+the+individual+feedstuffs+were+as+follows%3A+pasture%2C+0.63%2F0.66%3B+grass+silage%2C+0.32%2F0.43%3B+concentrate+intake%2C+0.39%2F0.34%3B+maize+silage%2C+0.32%2F0.33%3B+and+hay%2C+0.15%2F0.16.+Estimation+of+groups+of+feedstuffs+(forages%2C+energy-dense+feedstuffs)+mostly+resulted+in+R2+values+%3E0.50.+Including+the+parameters+milk+yield+or+concentrate+intake+improved+R2+values+by+up+to+0.21%2C+with+an+average+improvement+of+0.04.+The+results+of+this+study+indicate+that+not+all+ration+components+may+be+estimated+equally+accurately.+Even+if+some+estimates+are+good+on+average%2C+there+may+be+strong+deviations+between+estimated+and+observed+values+in+individual+data+sets%2C+and+therefore+individual+estimates+should+not+be+overemphasized.+Further+research+including+pooled+samples+(e.g.%2C+bulk+milk%2C+farm+samples)+or+variations+in+ration+composition+is+called+for.&rft.date=2017&rft.type=Journal+paper&rft.type=NonPeerReviewed&rft.format=application%2Fpdf&rft.language=en&rft.identifier=%2Fid%2Feprint%2F32819%2F7%2FKlaffenbock%2520et%2520al..pdf&rft.identifier=+++Klaffenb%C3%B6ck%2C+M.%3B+Steinwidder%2C+Andreas%3B+Fasching%2C+C.%3B+Terler%2C+G.%3B+Gruber%2C+L.%3B+M%C3%A9sz%C3%A1ros%2C+G.+and+S%C3%B6lkner%2C+J.+++(2017)+The+use+of+mid-infrared+spectrometry+to+estimate+the+ration+composition+of+lactating+dairy+cows.+++American+Dairy+Science+Association%2C+100+(7)%2C+pp.+5411-5421.++++++++&rft.relation=10.3168%2Fjds.2016-12189&rft.identifier=10.3168%2Fjds.2016-12189&rft.doi=10.3168%2Fjds.2016-12189