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Effect of stocking density on social and feeding behavior of prepartum dairy cows
The objective of this study was to investigate the effect of 2 feedbunk stocking densities on prepartum social and feeding behavior of dairy cows. Seven hundred fifty-seven Jersey cows at 4 wk prior to expected calving date were assigned randomly to 1 of 2 treatments. Treatments were 80% (38 cows/48 headlocks; 80D) or 100% (48 cows/48 headlocks; 100D) feedbunk stocking density. Four pens with sand bedded freestalls were utilized: 2 nulliparous and 2 mixed primiparous and multiparous referred to as ‘parous’ pens over 4 repetitions (a total of 350 nulliparous and 407 parous cows were used). Cows were balanced for body condition score and cows with a locomotion score > 2 were excluded from the study. Pens were stocked twice a week to maintain the desired stocking density. Displacements from the feedbunk were measured using video recordings during 3 h following fresh feed delivery on d 2, 5, and 7 of each week of the 5-wk rep. Feeding times were measured using 10-min video scan sampling on d 2, 5, and 7 of the first week of the rep and d 2 and 5 for the final 4 wk of the rep. Displacements and feeding behavior data were analyzed using PROC MIXED of SAS with observation day (rep) as repeated measures. The random statement cow ID (pen) was included for the feeding behavior model. The 80D cows had fewer displacements from the feedbunk than 100D cows (15.2 ± 0.7 and 21.3 ± 0.7, respectively; P < 0.001). There was a treatment × parity interaction for daily feeding time (P = 0.014). Parous 80D cows had a tendency for longer feeding times than parous 100D cows (296.9 ± 3.3 and 289.3 ± 2.9 min, respectively; P = 0.081) whereas there was a tendency for longer feeding times for nulliparous 100D than nulliparous 80D cows (251.2 ± 3.2 and 242.8 ± 3.6, respectively; P = 0.079). In conclusion, stocking cows at 80% of headlocks reduced displacements from the feedbunk and had a tendency to increase daily feeding time for parous cows, but not nulliparous cows.
Keywords:
stocking density, transition cows