Individual and maternal heterozygosis in multibreed bovine populations of different productive systems for beef cattle in Colombian low tropics

摘要

Inordertoquantifytheheterosis-environmentinteraction(HEI)andracialproportion-environmentinteraction(RPEI)inmultibreedbovinepopulationoftheColombianNorthwest,registriesfrom16herdslocatedinthreeagroecologiczones(AZ1,AZ2,AZ3)fromlowtropicsystems(humidsubtropicforest,humidtropicforestanddrytropicforest,respectively),betweenyears1995to2007.Weightat12-mo(W12),weightat18-mo(W18),andweightat24-mo(W24),theywereevaluatedwith2022,1660and1352observationsrespectively;withpredominanceanimalsofthebreedsandcrossbredbetweenAngus(A),BlancoOrejinegro(B),Zebu(Z),andRomosinuano(R)wereused.Mixedmodels,therandomeffectsofthezone,andtheinteractionbetweentherespectiveheterocigosisorracialproportionbyzonewereincluded.Asfixedeffectsstudiedthepercentageofheterocigosisbycrossover,whichcanbeindividual(HITotal)orcebuíno-bullfighting(HICT)orbullfighting-bullfighting(HITT)ormaternal(HMTotal)orcebuíno-bullfightingmaternal(HMCT);aswellastheracialproportionofA,BandR,thecontemporarygroup(year-time-sex)andthecovariableage,appearingsignificanteffect(p0,001)ofbothlastonthethreeevaluatedvariables;alsosignificanteffect(p0.05)nbsp;forthemaineffectsofHItt,HMTotalandHMctwasdetermined,onP24,withnegativeestimativasof-0.4815;-0.1547and-0,1546respectively.nbsp;TheresultsindicatedthattoagreaterproportionofheterocigosistheperformanceoftheanimalsforW24ispoorer,diminishing482geach1%ofincreaseinIHBBand155geach1%ofincreaseinMHTotalorMHZB.Betweenthedifferentzones,weresomesignificantdifferences(p0.05)forheterosisandproportionofraces,particularlyintheIHTotalbyzoneinteractionsinW12andW18,whereAZ2surpassedtheeffectofAZ1forW12;whereasforW18,AZ1andAZ2weresuperiortoAZ3.InthecaseofIHZBbyzoneinW18,AZ1andAZ2weresuperiortoAZ3,whereasforW24,AZ1andAZ3surpassedtoAZ2.InAZ3forW12atgreaterAngusorRlevelthereisbetterperformance,inW18isdesirableagreaterproportionofAngusandforW24,animalswithgreaterproportionofR;theBbreed,ontheotherhand,doesnothaveagoodperformanceinAZ3.nbsp;