THE GENETIC STRUCTURE OF LACTO-PROTEINS AT KARAKUL SHEEP

Silvia Evtodienco, O. Mashner, Valentina Petcu, Ana Chiţanu

Abstract
    Sheep farmers in Moldova pay particular attention to milk production. This is economically motivated. Regardless of race and destination, all the sheep are milked, and the obtained milk is processed by artisanal methods. The study of the genetic structure of lacto-proteins allows homozygous (BB) animals to be identified in the kappa-casein locus, which, according to the bibliographic data, have an increased yield in the manufacture of cheeses. Research on the "Botnari V.Gh." farm showed that from 75 of milking sheep 3 sheep or 4.0% are holders of homozygous alleles BB, 10 or 13.3% heterozygous alleles of AB and 62 or 82.7% of AA alleles.
   According to the chemical analysis of the milk, it was found that the sheep with the genotype BB exceeded those with the genotype AA by the amount of: fat with 21.9%, proteins with 19.04%, including casein 22.7%, lactose with 5.9 % (P<0.001) and serum proteins with 7.6% (P <0.01). Sheep with heterozygous genotype AB also genuinely exceed those with AA genotype by the amount of fat with 12.3%, protein with 10.6%, casein with 12.3% (P <0.001) serum protein with 5.4% (P <0.01).
   In order to increase in flock the number of sheep with the homozygous alleles BB and heterozigote AB were selected from the sheep- mothers the possessors of these alleles, 4 gray lambs for breeding and reproduction, which will allow to increase the weight of sheep with the required genotype.

Key words: Sheep karakul, k-casein, genotype, milk, chemical composition