This study investigated changes of milk production in dairy cows intramuscularly injected with drugs containing dexamethasone (DXM). Three types of dexamethasone formulations (Bueunde® (DXM 0.5 mg/mL), Dexason INJ.® (DXM 1 mg/mL) and Dexolone-20 inj.® (DXM 1 mg/mL)) were intramuscularly injected into sixteen healthy dairy cows each. Bueunde® was intramuscularly injected into 8 dairy cows with 5 mg (BED-1) and 10 mg (BED-2) of DXM once a day for 3 consecutive days, respectively. Dexason INJ.® was intramuscularly administered once into dairy cows with 20 mg (DXS-1, n=8) and 40 mg (DXS-2, n=8) of DXM, respectively. Dexolone-20 inj.® was intramuscularly injected once into dairy cows with 20 mg (DXS-1, n=8) and 40 mg (DXS-2, n=8) of DXM, respectively. Milk production (MP) of BED-1 and BED-2 significantly decreased during the drug administration and up to 48-hour post-drug treatment. Compared with the MP before drug administration, the MP of DXS-1 and DXL-1 was meaningfully decreased by 36 and 24-hour post-drug administration, respectively, and that in both DXS-2 and DXL-2 significantly decreased until 48-hour post-drug treatment. In conclusion, it was confirmed that the MP temporarily decreased by 48 hours after administration of DXM to dairy cows.

• Woo H Kim(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Won-Seok Chae(Division of Life-Science and Chemistry, Daejin University)
• Kwang Il Park(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Yeung Bae Jin(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Suk Kim(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University)
• Ki-Rim Kim(Department of Dental Hygiene, Kyungpook University) Corresponding Author
• Hu-Jang Lee(Institute of Animal Medicine, College of Veterinary Medicine, Gyeongsang National University) Corresponding Author