[2 genetic systems of serum amylase in the Kholmogor breed of cattle].

All the genetic types of amylase I (AmI) and amylase II (AmII) known for the species Bos taurus are encountered in the Kholmogorskaya breed of cattle. Besides the two alleles, AmIB and AmIC found in all the other European breeds of cattle the locus in the Kholmogorskaya breed also includes a rare allele AmI-A hitherto considered to be characteristic only of zebu-like cattle. The frequencies of the alleles AmI-A, AmI-B and AmI-C in the Kholmogorskaya breed proved to be 0.014, 0.392 and 0.594 respectively (n = 1098). Of the two co-dominant alleles, AmII-A and AmII-B controlling the synthesis of the isozymes of the second amylase system the first is rare, occurring with the frequency of 0.131 (n = 245). The earlier assumption of Mazumder and Spooner, that there is no linkage between the genes of the loci AmI and AmII is corroborated. The breeds assigned to the Bos taurus brachyceros type have a lower frequencies of the AmI-C allele as compared to other breeds the origin of which is associated with the subspecies B. t. primigenius.