Prediction of Total Milk Yield in early lactation of dairy cows using Milk Composition Measures

摘要

Thisstudywasconductedtodeterminethepotentialofestimatingtotalmilkyield(TMY)ofdairycowsinearlylactationusingmilkcompositionmeasures.Thirteenprimiparousandfourtysevenmultiparous(F1)FriesianxBunajicowswereusedforthestudy.Cowsweremilkedtwicedaily(morningandevening)andmilkyieldwasrecordedondailybasis.Themilksampledforthedeterminationofmilkfat,proteinandlactosecontentswastakenonceperweekataweeklyintervalfrom4to100dayspost-partum.ThemilkcompositionanalysiswascarriedoutattheFoodScienceandTechnologyLaboratoryofInstituteofAgriculturalResearch,AhmaduBelloUniversity,Zaria-Nigeria.Ordinaryleastsquare(OLS)regressionprocedurewasusedtodeterminetherelationshipofmilkcompositionvariableswithTMY.TheresultsshowedthatthesinglemostinformativemilkcompositionvariablethatcouldbeusedforestimationofTMYinearlylactationwasmilkfatcontent(MFC).Itexplainedabout46.27%ofthevariationinTMYwithverylowpredictionerror,andhasanegativeassociationwithTMY.However,whenmilkproteincontent(MPC)wasincludedinthemodel,thepredictionabilityofthemodelimproved(Rsup2;=53.00%),andthecombinationofthethreemilkcompositionvariables(MFC,MPC,MLC)explainedabout58.99%ofthevariationinTMYofthecows.Baseontheforegoingitispossibletoestimatethetotalmilkyieldofdairycowsinearlylactationusingmilkcompositionmeasures.