[Development of feeding activities in dairy cows at the start of lactation and relation to the quantities of feed...

Feeding behaviour was measured in 12 multiparous dairy cows all day long during the first 5 weeks of lactation. These cows received corn silage ad libitum and concentrates representing 21 to 27% of total dry matter intake, depending on the week. During the first week of lactation, total eating and ruminating times were 364 and 426 min; eating and ruminating rates were 39.0 and 32.5 g DM/min. The feed intake increase during the first 5 weeks of lactation was accompanied by an increase in ruminating time (+ 22%) and eating rate (+ 26%). These two parameters were very sensitive to short-time decreases in DM intake. Animal variations of eating and ruminating rates, but not variations of total eating and ruminating times, were related to those of dry matter intake. Thus, animals which had the highest dry matter intake were those which had the highest eating and ruminating rates.