Abstract #167

# 167
Effects of trace mineral injections on liver and blood trace mineral concentrations in dairy cattle.
K. Kelly*1, E. Eckelkamp1, B. Kawonga1, D. Tracy2, C. Fendley1, J. Bewley1, 1University of Kentucky, Lexington, KY, 2Multimin USA, Fort Collin, CO.

Trace minerals (TM) such as selenium (Se), manganese (Mn), copper (Cu), and zinc (Zn) are required in small amounts by the body and are vital for dairy cow reproduction, immunity, and production. The study objective was to determine if a TM injectable increased liver and blood concentrations of Se, Mn, Zn, and Cu following calving. Sixteen primiparous and 16 multiparous were divided evenly into 2 treatment groups and received either 5 cc of TM injection (MM90; Multimin 90, Multimin USA, Fort Collins, CO) or 5 cc of sterile saline (CONT). Blood samples and liver biopsies for TM concentrations were taken at 60 and 30 d peripartum, and 14, 30, and 60 d in milk (DIM) relative to expected calving date. The GLIMMIX procedure of SAS (Version 9.4, SAS Institute, Inc., Cary, NC) was used to assess the effects of day, treatment, parity, and all 2-way interactions for all models on liver and blood Se, Cu, Zn, and Mn concentrations. Stepwise backward elimination was used to remove non-significant interactions (P ≥ 0.05) with all main effects remaining in the models regardless of significance. Lsmeans of Se and Cu liver concentrations decreased on 30 d peripartum and 14 DIM but increased after 30 DIM compared with d 60 d peripartum (P < 0.01, respectively). Multimin 90 lsmeans of liver Se increased 0.31 ng/g compared with CONT (P = 0.02). Lsmeans liver Cu increased significantly by 139.65 ng/g in multiparous compared with primiparous (P < 0.01). Liver Zn (P = 0.03) and liver Mn (P = 0.01) were significantly greater by over 39.32 ng/g and 0.97 ng/g on 14 DIM compared with peripartum days. No significant differences were found between the CONT and MM90 for liver Cu and Zn, blood Se, Cu, or Zn. Multiparous cows increased by 5.82 ng/mL in blood Se compared with primiparous (P = 0.01). Multimin 90 blood Mn levels increased by 1.22 ng/mL over CONT (P = 0.046). Trace mineral supplementation increased storage of Se and Cu, indicating MM90 may be a beneficial addition to dry cow management.

Key Words: trace mineral injectable, liver mineral concentration, blood concentration