Productive longevity and reproductive ability of the bulls’ daughters at different lineages

The article presents data on the assessment of two lines Red-and-white and Holstein bulls in terms of productive longevity and the reproductive ability of their daughters. It is established that the best indicators of productive longevity, lifelong milk yield and reproductive ability are in the daughters of Double 1479 (Vis Back Ideal line). The results of a two-factor variance analysis confirmed the influence of the factors «line» and «servicing bull» on the duration of economic use and age of daughters’ first calving.