OAHN Bovine Network Research Project: Trace Mineral Status in Ontario Beef Herds

Project Lead: Cynthia Miltenburg (OMAFRA), Jessica Gordon (OVC, MSU)

Collaborators: Megan Van Schaik, Jim Fairles, Ray Reynen, and Tanya Rossi

To view the full report, please download the PDF here: https://www.oahn.ca/wp-content/uploads/2023/08/Trace-Mineral-Report-Summary_FINAL-Project-030677.pdf

Executive Summary

Trace minerals play an important role in cattle health and deficiency is associated with a variety of conditions including reduced calf immunity, elevated calf morbidity, reduced weight gain, and poor reproductive performance. The objectives of this project were to provide veterinarians with the opportunity to assess mineral status in Ontario beef herds and increase surveillance on the risk for trace mineral disorders. Blood samples were collected from 684 cows and heifers from 69 unique cow-calf herds across Ontario. All herds reported providing some form of mineral supplementation pre-breeding. Notable findings on blood included most cattle being deficient or having less than adequate levels of selenium and approximately half of cattle having elevated or very high levels of molybdenum. Pregnancy outcomes met targets for most herds enrolled and a small number of herds that completed the follow up management survey reported deformed calves, stillbirths, weak born calves, or neonatal mortality. Trace mineral findings outside of normal ranges despite reported supplementation may indicate opportunity to optimize trace mineral supplementation including ensuring an appropriate mineral product is provided for the region and type of cattle at the recommended feeding rate and for the number of cattle in the group, and provided in a location that is clean, and desirable for cattle to access.