The primary source of minerals for beef cows comes from the pasture and forages they consume, as these contribute the most to their diet and are typically good sources of essential minerals. However, certain minerals may still require supplementation depending on forage quality and soil conditions.
Key Minerals:
- Calcium: Found abundantly in pastures, especially in legumes like alfalfa. It’s crucial for bone health, and its balance with phosphorus (ideal Ca:P ratio of 1.5-2:1) is important for proper nutrient absorption. Calcium deficiencies may lead to bone issues and kidney stones.
- Phosphorus: Important for energy transfer and reproduction. Phosphorus is typically sufficient in well-managed pastures, though it decreases with plant maturity and during droughts. Excess phosphorus can be wasteful and environmentally harmful.
- Potassium: Generally abundant in most pastures. High potassium levels, especially in spring or legume pastures, can reduce magnesium absorption, potentially leading to grass tetany.
- Magnesium: Critical for preventing grass tetany, a condition seen in cattle grazing lush pastures in early spring. Magnesium deficiencies can lead to nervousness, staggering, and even death in older cows. Supplements, such as magnesium oxide, are necessary during high-risk periods.
- Selenium: Many regions have selenium-deficient soils, leading to immune and muscular issues in calves. Supplementation through injections or commercially-prepared mineral mixes is often recommended.
Other Considerations: Distillers grains and corn gluten feed contain high sulfur levels, which must be accounted for in rations. Copper should also be managed carefully, especially when sheep are present, as they are sensitive to excess copper. Regular testing of forages, soils, and fecal matter can help optimize mineral supplementation and avoid overfeeding.
