Inbreeding in nucleous herds of Nellore cattle in Brazil

摘要

Theaimofthisworkwastoanalyzetheeffectofinbreedingin7258animalsbelongingtotwoherdsofNellorebreedbornamong1964and1999.Thecharacteristicsanalyzedwereweightsadjustedto120,240,365,450and550daysofage,respectively.Theinbreedingcoefficientswerecalculatedbyinversionofthediagonaloftheinversefromrelationshipmatrix.nbsp;Thenumberofendogamicanimals,aswellas,theinbreedingcoefficientsofallanimalsincreasedovertheyears.However,thelevelofaverageinbreedingobservedinthepopulationwaslow(2.84%).Inanefforttoevaluatetheeffectsofinbreedingonanimalperformance,dataweightswereanalyzedbyregressionmethodsthroughthegeneralizedlinearmodelprocedure.Foranalysis,valuesofweightsthatwereintherangeof0to7%ofinbreedingwereconsidered.Theweightsforallagegroupsstudiedshowedacubicbehaviorrelatedtothestudiedvaluesofinbreeding,butitwasnotanimportantsourceofvariationregardingtothetotalvariationobservedintheweights.