Short communication: Association between prepartum subclinical magnesium imbalance and postpartum diseases in grazing dairy cows in Southern Chile

• Published in: Tropical animal health and production Vol. 56; no. 6; p. 206
• Main Authors: Hernández-Gotelli, Constanza, Wittwer, Fernando, Wagemann-Fluxá, Catalina, Sepúlveda-Varas, Pilar
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.07.2024; Springer Nature B.V
• Subjects: Animals; Biomedical and Life Sciences; Cattle; Cattle Diseases - blood; Cattle Diseases - epidemiology; Chile - epidemiology; Commercial farms; Dairy cattle; Dairy farming; Dairying; Dystocia - epidemiology; Dystocia - veterinary; Endometritis - blood; Endometritis - epidemiology; Endometritis - veterinary; Evaluation; Female; Grazing; Hypomagnesemia; Lameness, Animal - blood; Lameness, Animal - epidemiology; Lameness, Animal - etiology; Life Sciences; Magnesium; Magnesium - analysis; Magnesium - blood; Magnesium Deficiency - blood; Magnesium Deficiency - epidemiology; Magnesium Deficiency - veterinary; Mastitis; Mastitis, Bovine - blood; Mastitis, Bovine - epidemiology; Metritis; Pasture; Postpartum; Postpartum Period; Pregnancy; Prevalence; Regression analysis; Regression models; Regular Articles; Veterinary Medicine/Veterinary Science; Zoology; Chile; Health; Welfare; Pasture; Transition period
• ISSN: 0049-4747; 1573-7438; 1573-7438
• DOI: 10.1007/s11250-024-04044-5

This study aimed to evaluate the relationship between prepartum subclinical hypomagnesemia (pre-SHMg) and the occurrence of dystocia, metritis, clinical mastitis, lameness, and subclinical hypomagnesemia postpartum (post-SHMg) in pasture-based dairy cows. Also, the difference in means of prepartum magnesium (Mg) concentration by postpartum health events was evaluated. A total of 890 dairy cows from 32 commercial farms located in southern Chile were enrolled. Cows were examined twice, once between 30 and 3 days before and once between 3 and 30 days after calving. Blood samples were collected on both assessments, and cows were considered as having SHMg if serum total Mg < 0.65 mmol/L. On the postpartum visit, cows were evaluated for metritis and lameness. Information about clinical mastitis and dystocia was collected from on-farm records. Data were analyzed using multivariable mixed linear models and multivariable mixed logistic regression models. The overall prevalence of pre-SHMg was 9.9%, and its presence was associated with the occurrence of post-SHMg (odd ratio [OR] = 5.7; P  < 0.0001) and metritis (OR = 3.1; P  = 0.04). However, we did not detect an association between pre-SHMg and dystocia, clinical mastitis, or lameness after calving. Prepartum serum Mg concentrations were lower in cows that developed post-SHMg than those that did not (LSM ± SE = 0.75 ± 0.02 mmol/L vs. 0.83 ± 0.02 mmol/L; P  < 0.0001). In conclusion, pre-SHMg was associated with a higher risk of post-SHMg and metritis in grazing dairy cows but not other postpartum health events.