Dairy cows are often overstocked. Some managers are now using “slick bunk” (i.e., feeding for 0 percent orts) management to save on feed costs, but this reduces the time that cows have access to feed.
Both practices may increase competition and affect feeding behavior in dairy cows. The aim was to determine the effects of temporal and spatial restrictions on the feeding and competitive behavior of group-housed cows.
Treatments were two levels of stocking (2:1 versus 1:1 cows:feed bin) and two levels of feed access time (14 versus 24hour a day access). Eight groups (each of six cows) were tested on each of the four treatment combinations for 1 wk, with treatment order assigned using a replicated 4×4 Latin square design. Dry matter intake (DMI), feeding time, and feeding rate were measured for the last four days of each week, and data were summarized daily and for the 2-hour period immediately after the morning feeding. Displacements were recorded for 2hours after the delivery of morning feed (peak feeding period) and 2hours following the afternoon milking. The DMI did not decline when temporal access was restricted (27.0 vs. 25.7±0.5kg/d), and was not affected by overstocking (26.4±1.9, mean ± SD).
Cows with restricted temporal access spent less time feeding (190.9 vs. 207.9±6.1min). Overstocked cows that were temporally restricted had greater feeding rates during the day (156 vs. 137±4g/min) and especially during the peak feeding period (175 vs. 146±4g/min) compared with cows that were not restricted. In the peak feeding period, overstocked cows had reduced DMI (3.0 vs. 3.4±0.1kg/h) and feeding times (20.8 vs. 25.8±1.0min/h) and increased feeding rates (161 vs. 138±4g/min). Cows with restricted temporal access had greater DMI (3.9 vs. 2.6±0.2kg/h) and time spent feeding (27.3 vs. 19.2±1.3min/h) during the peak feeding period compared with cows that had continuous access to feed.
Restricting temporal access in conjunction with overstocking resulted in the greatest increase in daily displacements (15.0 vs. 3.8±1.4 displacements/d); the majority of these occurred during the peak feeding period. Adequate space and time to access feed is essential to minimize feed bunk competition in indoor group housing systems.