Variations in feeding behaviour of high-yielding dairy cows in relation to parity during early to peak lactation
Abstract. The objective of this study was to compare the feeding behaviour of high-yielding dairy cows in relation to parity during early to peak lactation and to determine whether or not there was any relationship between variables describing their feeding behaviour and total feed intake. Information concerning feed intake of each individual dairy cow is especially valuable for the herd management, particularly in early lactation. However, technical requirements for implementation are rarely given. Therefore, relationships between feed intake and time-related feeding behaviour parameters are of special interest. Time-related parameters could be recorded on farm conditions adapted sensor technology. Seventy high-yielding lactating dairy cows in different parities (23 in the 1st lactation, 17 in the 2nd lactation, and 30 in the 3rd-and-more-lactation) with an average of 11 000 kg milk yield per year were fed using automatic feeders from the 2nd to the 15th week of lactation. 222 231 recorded visits were analysed in three equal periods (period 1 = 7–39, period 2 = 40–72, and period 3 = 73–105 days in milk [DIM]) during early to peak lactation. Visits were clustered in meals based on the estimated meal criterion (28.5 min). The present study yielded the following values for meal frequency, number of visits per meal, meal duration, meal size, daily mealtime, daily dry matter intake (DMI), and feeding rate over the course of the study were 7.61 ± 1.7 (mean ± SD) meals/d, 4.02 ± 1.68 visits/meal, 37.07 ± 13.77 min/meal, 2.96 ± 0.92 kg DM/meal, 272.18 ± 82.14 min/d, 21.46 ± 4.29 kg DM/d, and 85.56 ± 28.77 g DM/min, respectively. Younger cows had more meals per day, more number of visits per meal, longer daily mealtime but a smaller meal size, lower daily DMI, and lower feeding rate compared to older cows (P<0.001). Meal duration and meal size were highly related to the number of visits at feeder per meal (R2=0.55–0.63; P<0.001, R2=0.25–0.39; P<0.001 respectively). In addition, meal size was highly related to meal duration (R2=0.59–0.72; P<0.001). Results from this study, which analysed data based on meal criterion, showed a higher correlation between the selected parameters of feeding behaviour and feed intake. The high correlation between meal duration and meal size could be used to estimate feed intake.