PSIX-6 Diurnal movement and consumption patterns of calf-fed Holstein steers fed in confinement.

The objective of this trial was to quantify the association between feeding and movement behavior of calf-fed Holstein steers fed in confinement. Holstein steers (n=110) were randomly assigned to slaughter groups (254, 282, 310, 338, 366, 394, 422, 450, 478, 506, and 534 days on feed) in a 2x11 treatment structure and fed in pens with feed bunk nodes that captured feeding behavior. Individual variables included duration at bunk, duration of head down, dry matter intake (DMI), and number of bunk visits. During the last 28 d prior to harvest, each steer was fitted with an accelerometer to measure standing time, lying time, steps and lying bouts. Feeding behavior and movement data were matched in 15 minute intervals for 101 animals. Data was analyzed using a mixed model with repeated measures; fixed effects were treatment and time and a compound symmetry covariance structure was used. Movement and feeding behavior exhibited a bi-modal distribution. Standing time, duration at bunk, head down duration, DMI, and number of bunk visits for both groups initially peaked at 0900 to 0930 h; a second peak occurred at 1700 to 1900 h. Standing time was highly correlated with DMI (r = 0.93; P < 0.01) and duration at bunk (r = 0.91; P < 0.01). Steps peaked between 1900 and 2100 h and were correlated with DMI (r = 0.64; P < 0.01). Lying bouts were negatively correlated to bunk visits (r = -0.46; P < 0.01). These data illustrate a bi-modal pattern for movement and feeding behavior within a 24 h period and provide evidence of a strong relationship between feeding and movement behavior of cattle fed in confinement.