Copper and manganese levels are associated with infectious abortions, stillbirths, and early neonatal deaths in upper Midwest beef cattle herds.

Objective: To determine the incidence of select mineral and vitamin deficiencies in beef cattle abortions, stillbirths, and neonates less than 24 hours old and to evaluate whether nutrient deficiencies are associated with causes of abortion.

Methods: A retrospective study of abortion cases from laboratory-performed necropsies and field-collected tissues submitted to the North Dakota State University Veterinary Diagnostic Laboratory over a 5-year period was conducted. Abortion investigations included gross and microscopic examinations, bacterial and fungal cultures, PCR assays, and quantitative analysis of the liver for copper, manganese, zinc, iron, selenium, cobalt, vitamin A, and vitamin E. Fisher exact tests, χ2 tests, and logistic regression analyses were performed to evaluate associations between minerals and vitamins and causes of abortion.

Results: Of 251 animals, 34% of abortion cases were attributable to a known cause. All but 4 animals were late gestational or full term. There was no sex predilection. When evaluated independently, minerals and vitamins were not associated with whether the cause of abortion was known. However, using logistic regression with mineral concentration (wet weight), there was an increased risk of infectious abortion with lower levels of fetal liver copper and higher levels of fetal liver manganese.

Conclusions: Copper and manganese levels are associated with infectious abortions, stillbirths, and neonatal deaths within 24 hours of birth in upper Midwest beef cattle herds. Incorporating liver trace mineral analysis into abortion investigations is crucial for a comprehensive diagnostic strategy.

Clinical relevance: Practitioners should consider the impact of mineral status when evaluating the cause of abortion in beef cattle.