Heterosis and reciprocal effects of growth performances in F1 crosses generations of Local X Hubbard chicken in the Western Highlands of Cameroon

摘要

Thisstudyhadasobjectivetocontributetothegeneticimprovementofthelocalchickenbydirectandreciprocalcrossingswithanexoticstandardstrain.TheexperimentalbirdswheretheparentalgenotypesHH(pureHubbardstrain;88),LL(purelocalchicken;58)andtheirreciprocalcrossbredsHL(crossbredsHubbardroosterxlocalhen;36)andLH(crossbredslocalroosterxHubbardhen;39).nbsp;Itcameoutfromthestudythattheeffectofgenotypewassignificantonalltheparametersunderstudy.Theproductsofthecrossings(F1)presentedintermediateperformancestothoseoftheirpureparentsHHandLL.nbsp;Theeffectoftheheterosiswasingeneralweakandpositiveonlyinsomecases.Asrelatedtofoodconsumptionandfeedefficiency,negativeheterosisrevealedalowerconsumptionofthecrossbredsandabetterfoodconversionfortheLHattheseventhweek(-15.6%and-19.7%).Themeanparentsingeneralhadsomeperformanceshighertothoseoftheirdescendants,notablyforgrowthandconformationtraits,probablyduetobreedsused.TheresultsobtainedforLHinrelationtoHLareconfirmedbythereciprocaleffectanalysis.Itrevealedthatforallparameters,ingeneral,notablytheliveweight(311.6g),theDWG(19.3g),theconsumptionindex(-2.5)andthecarcassyield(577.8g),thelocalroosterxexotichencrossingwassuperiortotheexoticroosterxlocalhencrossing.Thiscrossingcould,consequently,allowhighergeneticgainsinshortertimeandthereforereachtheobjectivesofthecrossingsmorequickly.CrossingswithHubbardbreedupgradedthelocalchickenby6.8%and80.6%ofliveweightrespectivelyinHLandLHgenotypes,andcarcasspercentagesby17.5%and143.6%inthesamegenotypesascomparedtothepurelocalparentalgenotype.Thecoefficientofvariationforliveweightat7thweekofagewas13.8%inHLand16.1%inLH,whilethecarcassyieldvariedby17.3%and7.4%respectivelyinHLandLH.nbsp;Thelocalfowlcouldthenbefavourablyusedassirebreedincrossbreedingprograms,butseveralcrossinggenerationsandselectionwillbeneededforhomogenizationandstabilizationofaLHgenotype