History of management procedures and hierarchy in dairy cows.

This study assessed social interactions between cows in a 186 lactating cow herd, split into high milk yield (<35 wk into milking) and a low milk yield (>35 wk into milking) groups. The shifting hierarchical behaviors of the cows over 20 d was observed through analysis of video. The objective was to de- termine whether cows with a higher history of management procedures associated with treatment for common mastitis, lameness, and dystokia, would be lower in rank in the social hierarchy, and show more fluctuation in rank, than cows with a low management procedure history. A still-image photo li- brary of the cows in the herd was compiled so that every cow could be identified from video recordingsﰀ Cows were iden- tified as being in a high management history group (HMG) or a low management history group (LMG) based on their electronic farm management record. For blind analysis, the categorization into low and high management groups was made after the video analysis had been completed. Cows were filmed at the feed barrier using ﰅﰄﰆﰄ p ﰇﰄ fps GoProHero ﰈ cameras, each camera supported to give a stable image along the feed barrier. Activity and time budget analysis of individ- ual cow interactions from the video images allowed domi- nant (+) and submissive (–) interactions between cows to be notedﰀ No significant difference was found in the ﰉaverage hierarchical rank” between cows in the HMG and the LMG (P ﰊ ﰄﰀﰋﰋﰄ)ﰀ Heifers did rank significantly lower than cows, for example, when comparing heifers to cows in their third lactation (P = 0.004). The LMG showed a higher variability (deviation in means score) in rank than the HMG. This pilot study may aid understanding of possible long-term effects of common dairy management procedures. With further devel- opment, this method could (a) inform steps to reduce long- term impacts of common procedures, and (b) utilize altered hierarchical behavior as a detection tool for cattle showing long-term deleterious effects of previous management proce- dures. Cows that had a higher history of management for com- mon dairy cow conditions (lameness, mastitis, or dystokia) did not experience long-term effects on hierarchical behaviors during feedingﰀ However, significant behavioral differences in groups based on age were detected.