Selective dry cow therapy (SDCT) has been shown to not be worse than blanket administration of dry cow antimicrobial (ABX) when correctly implemented in the “right” herds. In SDCT scenarios, cows at high risk (HI; i.e. those likely to have or acquire intramammary infection [IMI] during the dry period) receive ABX and a teat sealant (TS) whereas low risk cows (i.e. those unlikely to have an IMI during the dry period) receive only TS. This has been implemented in many herds with success. However, there is some hesitancy by some producers to not give ABX to cows that have “higher” milk production at dry off, for fear of increased risk of IMI, even though studies to date have shown SDCT to work equally well in high (vs low) producing cows. Nonetheless, because some previous studies have demonstrated that cows producing high volumes of milk at dry off are at increased risk of acquiring a new IMI during the dry period, a tool that could help decrease milk production leading to less risk of mastitis could be beneficial in herds using SDCT programs.

Objective: Investigate the effect of the administration of Bovikalc Dry (BD) on bioeconomic and behavior outcomes in the subsequent lactation when used in SDCT herds by measuring:

a)Production outcomes: clinical mastitis (CM) events, subsequent milk production (MY), somaticcell count (SCC), and herd removal. b)Animal behavior and cow comfort: total activity time, lying time and bouts, rumination behavior,udder engorgement (mechanical nociceptive threshold testing – MNT), milk leakage, as well asteat distance, udder thermography.