Determination of influence of polymorphism of gene of erythropoetin receptor (EPOR) on productive qualities of sows and reproductive characters of boars of Belarusian meaty breed was realized in the conditions of the Republic of Belarus. Research results proved the possibility of EPOR gene application as a genetic marker which determined productive abilities of swine of Belarusian selection breed. Frequency of undesirable allel EPOR**c of EPOR gene in the analyzed swine stock balanced within the frames of wide range: from 44% for Belarusian meaty breed sows up to 78% for Belarusian Kripnaya Belaya breed sows. Analysis of influence of genotype with EPOR gene on multiple fetation of sows of Belarusian meaty breed showed that sows with the preferred genotype (EPOR**tt) statistically reliable (P less than 0,01) exceeded sows with undesirable genotype (EPOR**cc) in accordance with number of alive birth piglets on 1,7 heads. Among sows of Belarusian Kripnaya Belaya breed with genotype EPOR**ct there were stated multiple fetation indexes exceeding the sows with genotype EPOR**tt on 0,5 heads. Desirable EPOR**tt genotype irrespective of sow age rendered the positive influence on their multiple fetation. It was recommended to realize genetic testing on determination og polymorphism of gene of erythropoetin receptor among the animals of Belarusian meaty and Belarusian Kripnaya Belaya breeds. Selection of parental pairs of the selection nucleus was recommended to realize taking into consideration genotypes, giving preference to animals with EPOR**t allel

Determination of adaptation and compensation abilities of larval forms of cestodes (cysticercus and echinococci) was realized by means of evaluation of biochemical composition of their internal environment. There was realized the following estimation of biochemical composition of internal environment: Cysticercus tenuycollis from sheep - 34, Cysticercus tenuycollis from swine - 17, Echinococcus granulosus L. from swine - 23. Estimation of biochemical composition of custodies larvaceous forms was realized on the basis of the standard veterinary methods. Research results revealed that osmotic volumetric concentration of internal environment of custodies larval forms was lower than of osmolarity of blood serum. The average value of osmolarity of blood serum for both sheep and swine was 296,63 mmol/l. Research results showed presence of large quantity of specific lipo- and glycoproteins in custodies larva forms. Cysticercotic liquid administrated into suspended matter of microorganism Micrococcus lysadeicticus and leads to lyzing up to 5% of microbal bodies. It was possible to testify the presence of lyzing activity in liquid of larval forms of cestodes. The research results showed that the analyzed larval forms of cestodes had a lot of different and strong defense mechanisms. Adaptation and compensation abilities of larval forms of cestodes had nonspecific character and contained the following: physical mechanisms; humoral immunocompetent factors; and biochemical adaptation