Assessment of breeding and milking performance of polish holstein-friesian black-and-white cows (ho) and crosses with the norwegian red breed (ho × nr)

The aim of this study was to compare breeding performance traits (in heifers) and milking performance (primiparous cows) of the Polish Holstein-Friesian Black-and-White breed (HO) with those of the Polish Holstein-Friesian Black-and-White × Norwegian Red (HO × NR) F1 crosses kept under uniform environmental conditions. More advantageous breeding parameters and higher daily milk yields as well as lower daily contents of fat, protein, casein and dry matter and lower somatic cell counts in milk were recorded for F1 crosses (HO × NR) compared to purebred HO cows. In view of milk yield per lactation, greater contents of milk, fat and protein as well as lower concentrations of fat and dry matter in milk during the first 100 days in milk were found for crossbred primiparous cows. In turn, in the standard 305-day lactation milk coming from HO cows contained higher levels of protein and dry matter. In order to confirm the results obtained in this study it is advisable to con- duct further investigations on a larger population of cows of both genotypes, including assessment of their functional and production traits over their productive lives.