Seasonal and parity effects on some performance and reproductive characteristics of crossbred dairy cows raised under tropical conditions of the Sudan

摘要

TheobjectiveofthepresentstudywastoestimatesomeperformanceandreproductivetraitsofcrossbreddairycowsraisedundertropicalconditionsoftheSudan.DatausedinthestudywerecollectedfromKenanadairyfarminthewhiteNilestate,subjectedtostatisticalanalysisusinggenerallinearstatisticalmodelaidedbythestatisticalpackageofStatstica.Thetraitsmeasuredweretotalmilkyield,dailymilkyield,lactationlength,dryperiod,calvingintervalageatfirstcalvingandnumberofservicesperconception.Paritynumberhadasignificanteffectonlyontotalmilkyieldanddailymilk;whereasseasonofcalvingsignificantlyaffectedonlytotalmilkyield,andlactationlength.nbsp;