Feeding behavior of lactating dairy cows as measured by time-lapse photography.

Evaluation of feeding behavior of ad libitum-fed lactating dairy cows by time-lapse photography revealed 68% of the total feeding activity occurred between the daylight hours of 0600 and 1800. Cows consumed an average of 12.1 meals/day, each 20.9 min in duration. Only 58% of the total defined meal time actually was spent eating, or 253.6 min/cow per day. Estimated meal size and rate of eating, as well as total daily time spent eating, were greater for cows as compared to animals with lower energy demand. Certain feeding characteristics, such as meal frequency and duration, were variable among animals, suggesting that these behaviors may be characteristics of individual cows. Results by time-lapse photography compared well with direct measurement by weigh-cell apparatus.