Effects of a maternal bovine appeasing substance at dry-off on dairy cow behavior following dry-off

Objective The primary objective was to determine whether administration of maternal bovine appeasing substance (MBAS) at abrupt dry-off influenced rumina-tion time. The secondary objectives were to evaluate its effects on eating time and activity during the first 14 d after dry-off. Materials and Methods Enrollment of 203 Holstein cows (primiparous and multiparous) from a commercial dairy in Minnesota occurred between July and November 2024. Cows were assigned at dry-off to either a control group (CON; n = 100) or a MBAS-treated group (TRT; n = 103), with enrollment conducted in contemporaneous TRT and CON clusters across 6 enrollment events (12 clusters total). Cows in the TRT group received a single topical application of 15 mL of MBAS at dry-off, whereas CON cows received no treatment. To minimize cross-con-tamination, CON and TRT cows were housed separately while the MBAS active ingredient was present. Rumina-tion, eating, and activity—representing the magnitude and frequency of cow movement relative to individual baseline behavior—were monitored using neck-mounted sensors, and data were analyzed using linear mixed models. Results and Discussion Rumination was greater in TRT at 429 min/d compared with CON cows at 402 min/d (+27 min/d; 95% CI: 7.9, 45.5). Eating was also greater for TRT at 304 min/d compared with CON cows at 285 min/d (+19 min/d; 95% CI: 5.4, 31.3) during the first 14 d after dry-off, with the largest differences ob-served between 3 and 6 d after dry-off. No differences were detected in activity during the same period. Implications and Applications These results sug-gest that MBAS administration at dry-off promoted a more pronounced increase in rumination and eating dur-ing the early dry period compared with no administration of MBAS. This demonstrates that although both groups began adapting to the dry period, MBAS further support-ed the expression of these behaviors, offering a practical strategy to reduce the disruption of important behaviors such as ruminating and eating during the transition from lactation.