Analiza zmian wydajności mleka i tłuszczu w kolejnych laktacjach krów rasy nczb oraz mieszańców z różnym udziałem genów bydła HF

Changes of milk and fat yields in the first three lactations of Lowland Red-White /LRW/ and LRW x HF hybrid cows with various contribution of HF genes were investigated. The cows were kept in two big herds with average milk yield 5000 kg per cow per year. The research showed that the hybrid cows had more even first lactation curves when compared to LKW cows. The most even were first lactations of hybrid cows with 25 % share of HF genes. Subsequent lactations of LRW cows were more even when compared to hybrid cows.