Studies on the reproductive performance of crossbred dairy cows raised on smallholder farms in eastern Usambara mountains, Tanzania

摘要

Aretrospectivequestionnairebasedcross-sectionalstudywasconductedtoassesreproductiveperformanceandfactorsinfluencingreproductiveefficiencyofcrossbredcowsinsmallholderfarmsinAmani,Tanzania.ThestudywascarriedoutduringtheperiodofOctobertoNovember2003.Thestudyalsoestimatedthefrequencyanddeterminantsoflongcalvinginterval(LCI),retentionoffoetalmembrane(RFM),dystocia(D),andabortion(A)insmallholdercrossbredcattleandexploredbirthtrends.Sixty-threedairyfarms(averagebreedablecows=2,range1to9)werevisitedanddataonreproductive,breedingandmanagementhistorieswerecollectedandstatisticallyanalyzed.Overall,179breedablecowswereobservedtobealiveatsomestagein2002.Thesecowscontributedatotalriskperiodof62,780cowdays,equivalentto2,093cowmonthsor171.9cowyears.Themean(#177;SE)calvingintervalandtheintervalbetweencalvingandtheinitiationofovarianactivitywere476#177;14and108#177;6.7days,respectively.Birthratewas52per100cowsyears,withbirthbeenreportedtooccurinallmonthsoftheyear.Ofthe123cowsthatwerereportedtohavecalvedmorethanonceintheirlifetime4(3.3%),3(2.4%)wereassociatedwithabortionanddystocia,respectively.Fifteen(12.2%)oftheanimalssufferedRFM.SignificantfactorsthatwereassociatedwithLCIandRFMaswasrevealedfrommultiplelogisticregressionmodelswereageofthecows,distancerangebetweenbullsourceandcows,farmerattendingbasicanimalhusbandrytrainingandtheownerofthecows.Cowthatwaslocatedover2kmawayfromthebreedingbullsourcewasassociatedwithLCI(Oddratio[OR]2.7,P=0.020)andoldercowwithloweroddsforRFM(OR=0.97,P=0.001).AnimalsbelongingtomaleandafarmerwhohasattendedabasictraininghadloweroddsforLCIandRFM(OR=0.31,P=0.001formalecowownerandOR=0.37,P=0.033forattendingtraining,respectively).Thoughnotstatisticallydifferent(P0.05),poorreproductionperformancewasalsolinkedwithfarmmanagerialfactors.Undernutrition,poorheatdetectiondespiteoffarmerbeingawareofthecardinalsignsofheat,poormonitoringofheatsignsduetotheinadequateusageofbreedingsupportingtoolswerealsofoundtonegativelyinfluencereproductionefficiency.Weconcludethat,thepresentestimateofLCI,birthrate,prevalenceofperipartumdisordersofteninterlinkedbyfarmmanagementalattributes,indicateandsuggestpoorreproductiveperformancesofcowsinAmanismallholderdairyfarms.Identificationandquantificationofthespecificreproductivedisordersandassociatedinteractingfactors(feeding/managemental)contributingtosuchpoorreproductiveperformancecallfordetailedinvestigation.