Özet:

The aim of the study was to analyse milk performance traits of Montbéliarde cows imported from France as pregnant heifers and born in Poland, taking into account season of birth and age at first calving. Daily yield (in kg and converted to kg FPCM), content of fat, protein and lactose, the fat-to-protein ratio, and somatic cell count in the milk were analysed. Born in Poland cows have higher daily milk yield and a better fat-to-protein ratio than cows imported from France. The imported cows produced milk with a more favourable chemical composition. In terms of daily yield, calving ages at 855–915 days were most beneficial in the case of both imported and born in Poland cows. Age at first calving had a greater influence on the yield of born in Poland cows than on that of imported ones. In each range of age at first calving, higher fat and protein contents in the milk of imported cows as compared to cows born in Poland were noted. The somatic cell count in the milk may indicate somewhat better udder health in the born in Poland cows. In the case of both imported and home-bred cows, the spring/summer season of birth was associated with higher somatic cell count. In conclusion, the acclimatization process may have had a negative effect on the performance of cows imported as pregnant heifers from France.

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