Parentage Testing With Microsatellite And SNP Markers In Simmental

Pedigree information plays an important role in cattle breeding. It can be used in QTL mapping,genome-wide election and genetic evaluation based on BLUP model. The experimental population ofthis study was Simmental come from Mongolia ulgai. Since grazing, natural mating and artificialinsemination breeding methods and extensive management, pedigree record deletions and errors weremore serious. Pedigree errors would reduce the accuracy of genetic evaluation and reduce geneticprogress. So it was very necessary to carry out paternity testing in Simmental.The objective of this study was to optimize Simmental’s paternity testing based on STR andestablish Simmental’s paternity testing system based on SNP. Then paternity analyses were carried outwith this two sets, to correct the potential errors of pedigree, establish a complete and accurate pedigreesystem, improve the accuracy of the estimated breeding values and finally accelerate genetic progress ofSimmental.The results were as follows.1. A set of8STR was selected as Simmental’s paternity testing system, containing BM2113,TGLA122, ETH225, INRA023, TGLA53, CSSM66, HAUT27, INRA037.BM1824and INRA032wereselected as candidate loci.The average of alleles number,expected heterozygosity and polymorphismcontent information were11.4,0.828and0.8038, respectively, indicating that the set had highpolymorphism in Simmental. Their cumulative exclusion probability reached0.99,0.9995,0.999998onthree different occasions, suggesting that this set having high power to assign parternity in Simmental.2. A set of50SNP was selected as Simmental’s paternity testing system. The average of minimumallele frequency, expected heterozygosity and polymorphism content information were0.4818,0.4998and0.3748, respectively. The cumulative exclusion probability was0.9989without known mothers；thecumulative exclusion probability would be higher if the mother was known。3. Paternity analysis was carried out with STR set in107calves. Totally78calves found his fatherwith80%confidence. Among78calves,32calves found his father with95%confidence and46calvesfound his father with80%~95%confidence.4. Paternity analysis was carried out with SNP set in938calves. Totally385calves found his fatherwith80%confidence. Among78calves,268calves found his father with95%confidence and117calves found his father with80%~95%confidence.