Selection Of Micro-satellite Markers For Molecular Genealogical Confirmation And Their Association With Production Traits In Holstein Dairy Cows

Wrong and missing pedigrees were common occurred in dairy cow production,leading to inbreeding depression and reducing the genetic diversity.It can retard dairy’s genetic gain and produce a great impact on breeding selection and genetic improvement of dairy cows.The objective of this study was to optimize a set of micro-satellite Markers using for paternity testing and establish an effective method for both paternity testing and pedigree building.We have preliminary screened 18 micro-satellite from ISAG and collected blood,hair follicle or semen from 309 farm cows.We finally choosed 8 micro-satellite Markers(TGLA122 、TGLA227、BMC1207、INRA134、INRA037、BM103、MB026 and BP7)after agarose gel and polyacrylamide electrophoresis detection for paternity testing of Chinese Holstein cows.Cervus 3.0 was used for calculating the alleles,allele frequency,polymorphism information content(PIC),observed heterozygosity(Ho),expected heterozygosity(He),exclusion probability(PE),combined exclusion probability(CPE)and the Hardy-Weinberg equilibrium.The GLM procedure of SAS was used to analysis the correlation between eight micro-satellites and six production traits.The results are as follow:The eight micro-satellite loci showed different polymorphism.The number of alleles ranged from 7 to 19.The mean number of allele was 14.63.The Marker TGLA122,TGLA122 and INRA134 had 19 alleles for each with the highest polymorphism.The Marker BMC1207 had 18 alleles with higher polymorphism and the Marker BP7 had 7 alleles with lowest polymorphism.All Markers showed higher polymorphism information content and expected heterozygosity.The PIC ranged from 0.520 to 0.866 and the average was 0.747.The PIC of all Markers was greater than 0.5.The He ranged from 0.553 to 0.880 and the average was0.718.All these showed that eight micro-satellite were highly polymorphic loci.The exclusion probability one in 8 Markers ranged from 0.181 in MB026 to 0.601 inTGLA227.Three Markers’ s value were more than 0.5.The combined exclusion probability one reached 0.99.The combined exclusion probability two was greater than 0.99.So the eight micro-satellite can be used in paternity testing.With the results of GLM procedure,we got the following conclusions: Marker BP7 had a significant effect on protein yield(P<0.05),it also had a highly significant effect on fat yield(P<0.01).Marker INRA134 had a significant effect on protein yield and fat yield(P<0.05).Marker BM103 had a significant effect on fat percentage(P<0.05).