摘要：The genetic characteristics based on microsatellites in Brown cattle breed reared in Bulgaria is unknown. In the present study 11 microsatellite (STR) markers recommended by ISAG/FAO in cattle were used for the first time to genotype and evaluate the genetic diversity in 52 animals from the Brown cattle population in Bulgaria. All of the studied loci were informative and polymorphic. In total, 77 alleles were detected with a mean number of 7.00 at 11 microsatellite loci, from which 27 (36%) were with frequency lower than 5%. Allele frequencies ranged from 0.010 to 0.490. The highest number of alleles were found in TGLA227 and TGLA122 (11 alleles) while the lowest in BM1824 and TGLA126 loci (4 alleles). Microsatellite markers used in this study showed PIC values from 0.58 (TGLA126) to 0.86 (TGLA227) with an average of 0.70The results from this study showed an appearance of homo- and heterozygous variants and their different distribution over the 11 microsatellite loci. The highest number of heterozygotes was observed in locus TGLA227 (n=52) in which almost all individuals (48) were heterozygous. The lowest number of heterozygous individuals (18) was found in locus BM2113 (n=52). In our study the observed heterozygosity (Ho) and expected heterozygosity (He) varied from 0.643 (locus TGLA 122) to 0.942 (TGLA 227) and from 0.078 (locus BM2113) to 0.880 (locus TGLA227), respectively. This information is of importance for farmers to successfully design of breeding schemes to avoid inbreeding and to reduce the loss of some specific traits.
