Визначено чинники від яких залеж ить чутливість мікроорганізмів до полігексаметиленгуанідину (ПГМГ). Випробувано солі ПГМГ хлорид, валерат, малеат, сукцинат. О б 'єктами К л ю ч о в і с л о в а: бактерії, грибки, віруси, чутливість, полігексаметиленгуанідин, дезінфектант, фосфоліпіди.

candidate of agricultural sciences O. Honchar, candidate of agricultural sciences Yu. Sotnichenko, candidate of agricultural sciences V. Machulnyi Cherkasy experimental station of bioresources of the national academy of sciences The purpose. To justify application of analyzing crossing in populations of domestic dairy breeds. Methods. Analysis of scientific probes of foreign authors concerning application of analyzing crossing, assessment of attributes of breeding capacity of cows at crossing. Results. Necessity of use of analyzing crossing is justified. It is determined that at use of sperm production of breed Montbéliarde the amount of sperm doses for fruitful fertilization decreases, the amount of cows fertilized after the first fertilization increases, the share of heavy calving reduces for 8,2%. Frequency of postnatal complications at cows depended on history of calving. Conclusions. Positive results of analyzing crossing can be gained only at successful, weight selection of breeds, application of up to date procedures of assessment of basic attributes of selection. Crossing should be considered as short-term method followed by pure breeding.