The aim of the investigation was to find out the degree of improving breed (Angler and Holstein of red-and-white colour) inheritance influence onto the dura-tion and efficiency of lifetime use of red dairy cattle. The investigation is carried out with retrospective analysis at 489 Ukrainian Red dairy cows, which till the beginning of inves-tigation had the theoretical possibility to lactate not less, than eight lactations. One stated the essential (up to P < 0,001) level of intergroup differentiation (10,4–29,8%) on the ma-jority of lifetime use and duration indices of Fattymilk intrabreed type cows of different inheritant share on improving Angler breed. The dynamics of intrabreed differentiation turned out to be curvelinear and multidirectional without steady tendency, but with signifi-cant high- and low share crosses’ advantage. The longest and the most effective was lifetime use of Holstinized intrabreed type cows. The inheritance share on improving breeds causes 7–18% of general phenotypic variability of studied traits.