Anotace:
The aim of this study was to evaluate the amounts of time that selected crossbreeds of Holstein (H), Red-Holstein (R), and Czech Fleckvieh (C) cattle spent chewing, eating, being physically active using a Vitalimetr 5P neck responder during the period around oestrus in all seasons of the year. Oestrus and the days preceding it greatly affected the times of events of increased activity, eating, and rumination. Eating and chewing times were longest for H cows, at 51–74%, and shortest for C cows, at > 88%. The number of events of increased activity was highest (533.4 ± 8.94 events, P < 0.01) for cows R 51–74%. Oestrus in dairy cows was manifested by decreases in the times of chewing and eating and the frequency of events of increased activity. Feeding time decreased by 8.01 min from the second day before oestrus to the day of oestrus. Rumination time also decreased from the second day before oestrus to the day of oestrus. Rumination time on the day of oestrus decreased by an average of 61.80 min but increased the next day by 33.39 min. In contrast, events of increased activity were highest on the day of oestrus (623 ± 7.68 events). Our findings on differences between breeds, lactation order, and months may contribute to the improvement of algorithms for detecting oestrus, thereby improving the economic status of farms.