Effect of prepartum grouping strategy on displacements from the feed bunk and feeding behavior of dairy cows

The objective of the current study was to determine whether providing stable pen management affected displacements from the feed bunk and feeding behavior of prepartum dairy cows. Two hundred and twenty-four nonlactating Jersey primiparous and multiparous cows were enrolled in the study. The 2 treatments were all-in-all-out (AIAO; 44 cows were moved into the close-up prepartum pen as 1 group, with no additions during the 5-wk repetition) or traditional (TRD; with weekly entrance of new cows to maintain a pen density of 44 cows). Cows (253 ± 3 d of gestation) were balanced for parity and projected 305-d mature-equivalent milk yield and assigned randomly to either AIAO or TRD treatments. At enrollment, cows with a body condition score <2 or >4 (1-5 scale; 1 = emaciated and 5 = obese) or with a locomotion score >3 (1-5 scale; 1 = normal gait and 5 = severely lame) were not included. Displacements from the feed bunk were measured weekly for both treatments when TRD cows were moved into the close-up pen (d 0) and additionally on d 1, 2, 3, and 7 for 3 h after fresh feed delivery. A displacement rate was created to take into account differences in stocking density throughout the experiment. Displacement rate was calculated as the number of displacements divided by the number of cows in the pen at that time. Feeding behavior was measured using video 10-min scan sampling for 24-h periods at d 0, 1, 2, and 7. Displacements and feeding behavior were recorded for all 5 wk of each repetition. Treatment × week interactions were detected for number of displacements and displacement rate. The TRD treatment had more displacements from the feed bunk than AIAO in wk 1, 3, and 5, with no differences in wk 2 and 4. Similarly, the TRD treatment had a greater displacement rate than the AIAO treatment in wk 1 and 5, with a tendency in wk 3. No differences between the treatments were detected in wk 2 and 4. A treatment × week interaction existed for feeding time. Cows housed in the AIAO treatment had longer average feeding times in wk 2 with a tendency in wk 3, but spent 39 fewer minutes eating than those in the TRD treatment during the wk 1 of the study. Housing prepartum close-up cows with stable pen management reduced displacements from the feed bunk and altered average daily feeding times.