Genotype by environment interaction in “Siboney de Cuba” cattle

摘要

Thenewgenotype#8220;SiboneydeCuba#8221;(5/8Holstein,3/8Zebu)hasbeendevelopedsincethe70#8217;s.Themainobjectivewastoobtainanimalswithgoodresultsconcerningproductiveandreproductiveperformanceandtheiradaptationtothetropicalconditions.Iftheresultsofcomparisonsvarydependingtheenvironmentsinwhichthegenotypesareconducted,thereisgenotypebyenvironmentinteraction(IGE).Thevariationinresultsmayinvolveachangeinranking.From1980uptotheyear2000,atotalof2983#8220;SiboneydeCuba#8221;cowsfromfielddatafromtheHabana#8217;sGeneticEnterprisewereanalizedinordertoknowtheexistenceornotofIGEinmilkproduction(PL244)andcalvinginterval(IPP).Thelevelsproductionwereconsidered#8220;normal#8221;(1980-1990)and#8220;low#8221;(1991-2000).Thefixedeffectswereanalizedbyalinearmodel:herd,calvingmonth,calvingyearandparityweresourcesofvariation.Theheritability(h2)andbreedingvalues(VG)wereestimatedbyBLUPmethodologywithMTDFREMLsoftware.Withthebreedingvaluesofthesiresrepresentedinbothlevelsthecorrelationwereestimated.fnbsp;Allsourcesofvariationweresignificantforthetraitsandlevels.Theh2were0,12and0,04forPL244and0,14and0,12forIPPinlevels#8220;normal#8221;and#8220;low#8221;,respectively.Thecorrelationsbetweenbreedingvaluesinthetwolevelswere:0,47and0,08forPL244andIPP,respectively.TheseresultssuggestthatIGEexistsundertheconditionsofthisstudyandthattheutilisationofthesiresshouldbeaccordingtotheenvironmentalconditions.