Feeding behaviour in dairy cows with and without the influence of clinical diseases or subclinical disorders
The objective of this study was to describe and compare circadian pattern of feed intake and feeding behaviour in healthy and diseased dairy cows. Test animals (n=138) were separated into two groups according to their health status. Health and management data were used to exclude cows with clinical or subclinical diseases. Fifteen cows of the test herd complied with the defined criteria and formed the reference group »healthy«. The behaviour of the remaining 123 cows was compared with the reference group. Both groups were used to analyse the feed intake and feeding behaviour on a daily base and in the course of 24 h. During a defined time range from day 28 post-partum to day 56 post-partum behavioural differences within these groups were analysed. There were no significant differences in daily feed intake (40.7 vs. 41.9 kg fresh matter per day, P=0.42). However, feeding behaviour pattern differed between the two groups (daily feeder visits, daily feeding time, number of daily feeder visit, number of daily meals, meal duration, feeding time within a meal, feeder visits per meal). For example, average feeder visit was shorter in the group with subclinical/ clinical health disorders than in the reference group (7.2 vs. 8.1 min, P=0.024). Differences in circadian feeding behaviour could be detected by analysing the feed intake and feeding time over the course of the day. Linear regression analyses showed strong correlations between feeding time and feed intake on hourly base (R² = 0.8) and on daily base (R² = 0.7).