[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.