Rumination and its relationship to feeding and lying behavior in Holstein dairy cows

The objective of this study was to describe the relationship between rumination and feeding and lying behavior in dairy cows. Rumination time was monitored electronically using HR-Tags (SCR Engineers Ltd., Netanya, Israel). Feeding time and dry matter intake (DMI) were monitored using Insentec feed bins (Insentec BV, Marknesse, the Netherlands). All measures were collected in 2-h periods for 42 mature Holstein cows for a minimum of 9 d in the early dry period. Pearson correlation was used to describe associations, among 2-h periods within cow, first examining the relationship within a single period, and then modeling how this relationship changes when a lag of 2, 4, or 6h was imposed. Periods when cows spent more time ruminating were associated with lower feeding times and lower DMI (r = -0.71 and r = -0.72, respectively), likely because cows were unable to feed and ruminate simultaneously. The correlations with rumination time changed from negative to positive when lags of 2, 4, and 6h were modeled (r = -0.09, 0.24, and 0.15, and r = -0.16, 0.23, and 0.17 for feeding time and DMI at lags of 2, 4, and 6h, respectively). These results indicate that following periods of high feeding times and intakes, cows spent more time ruminating. This relationship peaks at approximately 4h after feeding. Periods of rumination were also associated with time spent lying down. Cows that spent more time ruminating per day, spent less time feeding (r = -0.34) and rumination times did not relate to DMI (r = 0.11). These data indicate that rumination time can be used to estimate within-cow variation in feeding behavior and intake, but daily summaries of rumination behavior are a poor indicator of DMI.