[The testing of bulls for the polledness gene].

Main regularities have been stated concerning the poll gene inheritance by the progeny of breeding bulls mated with cows of various (homozygous and heterozygous) genotypes by the "poll" or "hornedness" genes.

[The genetic selection aspects of the "Holsteinization" of dairy cattle breeding in Ukraine].

Results of the use of Holstein-Friesian bulls in milk-production cattle breeding in Ukraine have been stated. Genetic consequences of crossbreeding have been noted. An analysis of pedigrees of Holstein bull has shown the availability of predecessors carriers of genes BLAD, mule-foot, dumps with frequency of their recessive forms 34, 19.

[The criterion of lactation stability in cows].

The stability of the lactation curves of high-productive cows (4000-9000 kg of milk per lactation period) was investigated. A new criterion of assessment of the lactation stability was proposed. Basic genetic criteria of the index of lactation stability (coefficients inheritance and reiteration) were responded.

[A statistical genetic analysis of the calving traits of cows of a Ukrainian beef breed].

The results of investigation of calving features in 371 cows of Ukrainian beef cattle were summarized. Variance and correlation analyses of factors affecting calving in cows were used. Breeds, pedigrees of parents and progeny, assessment of complicated and lethal calvings, duration of pregnancies and mass of newborns were registered.

[Interbreed differences in cattle by "phenes"].

Significant interbreed differences (between Simmentals and Black-and-White cattle) for 16 phenotypes of molar surface structure were detected in milk-cows. In Black-and-White cattle, 15 phenotypic variants of the head colour marks correlating with the body colour were found.

[Hematologic chimerism in cattle twins].

A cytogenetic examination of a cow and its offsprings, obtained by pair transplantations of the embryos was carried out. The fragile X and the heteromorphism of the chromosomes XX of this cow and some of its offsprings were revealed. The variability of the hematological chimerism of the pair transplanted embryos was observed.

[Use of genetic markers in breeding of a commercial cattle herd].

Combination of type estimation and use of immunogenetic markers to analyze genotypes of breed animals permits intensifying breeding and promotes more rapid obtaining of the desired inherited material. It is suggested to carry out breeding in commercial cattle herds under constant immunogenetic control.

[Genetic interrelationship between lactation maturity, fertility and life productivity in Simmental cows].

In Ukrainian simmental heritabilities of maturity rate defined as ratio of the highest to first lactation yields were 0.17. Single lactation production and longevity are negatively correlated (-0.

[Use of genetic markers to estimate and obtain animals of the desirable type].

Alleles of B blood groups in dairy cows of different genotypes have been analyzed allowing for the genetic distance, coefficient and degree of homozygosis. Application of the above information to select cows for bulls increases efficiency of breeding in dairy farming.

[A method for calculating a coefficient of inbreeding and specific weight of an ancestor in an animal pedigree].

A new method is suggested to calculate an inbreeding coefficient and specific weight of ancestor in animal pedigree. It promotes a 10-fold decrease in expenditures of labour as against the S. Wright-D.