The effects of dietary forage, social hierarchy, and stocking density on stress in lactating cows during relocation

Abstract

The objective of these studies was to determine the effects of forage fiber, social hierarchy, and stocking density on stress in lactating cows during relocation to new dairy facilities. In experiment one, 23 lactating cows were fed a basal ration, or the basal ration plus grass or alfalfa hay at 10% of DM offered from 3 wk pre-move to 9 wk post-move. In experiment two, 17 lactating cows were housed together before and after relocation and evaluated for dominance rank. In experiment three, 44 cows were housed together before relocation, then in pens of varying stocking density (0.67, 0.83, 1.0, or 1.17 cows per stall) post-move. In these studies, the effects of treatment on MY, lameness, behaviors, plasma cortisol, cow cleanliness, and DMI were monitored. In experiment one, cows fed grass or alfalfa hay diets had higher plasma cortisol concentrations on the day of relocation than cows fed TMR, but there were no differences in DMI or MY. Cows fed alfalfa hay or TMR had increased lameness scores following relocation; cows fed grass hay did not have increased lameness scores. In experiment two, there were no differences in plasma cortisol or lameness scores between dominant and subordinate cows. Subordinate cows had lower MY following relocation compared to dominant cows. In experiment three, cows housed at a stocking rate of 1.17 had higher plasma cortisol than cows housed at a stocking rate of 0.67. All cows had higher lameness scores following relocation, but cows housed at a stocking rate of 0.67 tended to have higher lameness scores than cows housed at stocking rates of 0.83, 1.0, and 1.17. In summary, some management practices may decrease the negative effects of stress on lactating cows during relocation.