The effect of sire's origin on milking performance traits of cows kept in stanchion barns

he aim of this study, conducted under identical environmental conditions and the stanchion barn housing system, was to compare milking performance traits and somatic cell count in milk of daughters sired by Holstein-Friesian Black-and-White bulls from various origin groups. Cows were divided into three groups depending on the region of sire's origin, i.e. Polish bulls, bulls from other European countries (the Czech Republic, France and Germany) and bulls from the USA. Analyses were conducted applying the following experimental conditions: the age group of cows (primiparous vs. multiparous), stage of lactation (≤ 40 days, from 41 to 100 days, from 101 to 200 days and > 200 days) and season of the year (spring, summer, autumn and winter). Results of this study indicate that at the stanchion barn housing system of dairy cows in order to increase milk yields the use of semen from bulls of imported Holstein-Friesian Black-and-White bulls seems to be beneficial. However, daughters of US bulls may be prone to elevated somatic cell counts in milk. In turn, cows sired by Polish bulls can be characterised by favourable milk solids contents.