GLC Magnesium Products
Our Magnesium Products are Made to Perform™
Magnesium doesn’t always get the attention it deserves; however, it plays a critical role in digestion and mineral absorption, directly affecting cattle health and productivity. And as research continues to show, magnesium needs aren’t one-size-fits-all—they shift throughout a cow’s life, from calf to dry cow. At GLC Minerals, we offer a range of magnesium formulations designed to meet specific nutritional strategy, feed system, and herd requirements. Whether you’re fine-tuning performance or preventing deficiencies, we’re here with macromineral solutions that fit.
Magnesium Carbonate Formula –
Efficient and Consistent
Our collection of magnesium carbonate supplements is scientifically formulated to deliver precisely what dairy cows need at every stage of life. Our highly soluble magnesium carbonate formulas absorb faster and more efficiently than the magnesium oxide formulas, delivering the exact amount of nutrients through smaller portions of product.
Why Magnesium Matters
What makes GLC’s magnesium products different and better? Let’s take a look at the benefits compared to competing brands:
GLC Minerals Magnesium Products
| Compound composition optimizes absorption |  |
| Fortifies bone strength and metabolic functions | |
| Precise particle sizing; integrates into feed, ensuring uniform intake | |
| Made in a locally sourced, safe food-certified facility | |
| Consistent source of calcium and magnesium | |
Ready to learn more?
Schedule time with one of our product experts!
| BRAND | OptiMag™ | BaseMin™ | BaseMin™+ | Multesium™ |
|---|---|---|---|---|
| INGREDIENTS | Calcium Magnesium Carbonate – CaMg(CO3)2 | Calcium and Magnesium Carbonates | Calcium Magnesium Carbonate – CaMg(CO3)2, S-CARB, Salts | Hydroxides, Carbonates and Oxides of Magnesium and Calcium |
| SIZES | 50# Bags 2000# Totes Bulk Truckloads | 50# Bags 2000# Totes Bulk Truckloads | 50# Bags 2000# Totes Bulk Truckloads | Bulk Truckloads |
| DIRECT TO FARM | | | | |
| FEED MILLS AND COOPS | | |||
| Download Data Sheet | Download Data Sheet | Download Data Sheet | Download Data Sheet |
Supporting the Production Cycle of a Cow with Magnesium
Choose the superior magnesium formula to support animal health while optimizing production. Our expert animal nutritionists recommend the following formulas based on the age and life cycle to maximize production:
Pre-weaning to Pre-calving
OptiMag™ + ReliaCal™ OR BaseMin™
Lactation to Dry-off
Multesium™
Talk to a GLC Animal Nutrition Expert
If you are ready to take cattle health to the next level, leading to increased milk production, lower health risks, and improved animal health and farm profitability, let GLC Minerals help get you there.
Schedule time with one of our animal nutrition experts who will answer all your questions and guide you through product selection.
Frequently Asked Questions
BaseMin, BaseMin+ and Optimag are available in 50# bags, 2000-lb totes and in bulk truckloads. Multesium is available through shipped bulk truckloads.
Yes! We offer direct-to-farm delivery for most of our magnesium supplements. Ask your GLC product expert about timing for your area.
You can view technical spec sheets for each formula by visiting our website:
OptiMag
BaseMin/BaseMin+
Multesium
Magnesium needs vary by cow type and stage of production:
- Dry beef cow: ~0.12–0.18% of total diet (dry matter)
- Lactating dairy cow: ~0.35–0.40% of total diet (dry matter)
- Growing cattle: ~0.10–0.20% of diet (dry matter)
Example: A lactating dairy cow eating 50 lbs of dry matter per day needs about 0.18 lbs (82 grams) of magnesium daily (50 lbs × 0.0036).
Our magnesium is Great Lakes sourced and manufactured at our food-safe facility in Green Bay, WI.
Magnesium carbonate is often preferred in cattle supplements when palatability and gentle digestion are key. It’s less bitter than magnesium oxide, which encourages better intake in free-choice mineral mixes, and its slower reactivity makes it easier on the rumen. While magnesium oxide is more concentrated and faster-acting—ideal for preventing deficiencies like grass tetany—magnesium carbonate is a better choice when consistent daily intake and gradual absorption are more important.
GLC Minerals is a fifth-generation, family-owned company with over 150 years of experience in mineral manufacturing, specializing in high-quality calcium, magnesium, and gypsum products for agriculture, animal nutrition, and industrial applications. Our commitment to quality is demonstrated through ISO 9001:2015 and Safe Feed/Safe Food certifications, ensuring consistent, lab-tested products tailored to customer needs. Strategically located on the Port of Green Bay, we efficiently source minerals from the Great Lakes region, providing reliable delivery and personalized service to support your operation’s success.