Magnesium oxide is used as a magnesium source in ruminant mineral programs and premixes. For buyers in Latin America, selecting 90%, 94% or 99% MgO only by the headline assay can miss important questions about reactivity, particle characteristics, handling and the complete ration.
Separate MgO assay from elemental magnesium
The stated grade percentage refers to magnesium oxide content, not elemental magnesium. Formulators should calculate the relevant magnesium contribution and consider all other sources in the ration. The current grade-specific TDS and batch COA take precedence over a general product description.
Why reactivity and particle size matter
Two materials with similar assay can behave differently because of raw-material source, processing, surface area and particle distribution. For ruminant programs, the nutrition team should define the intended function and the reactivity information needed for evaluation. Particle size and bulk density may also influence flow, segregation and dosing in a premix plant.
Compare grades on a common technical basis
- 99% MgO: high-assay option; request the full grade-specific specification.
- 94% MgO: documented feed-mineral option at MgO ≥94%; confirm all agreed impurity and physical limits.
- 90% MgO: available on request; verify the complete specification and application suitability.
A higher percentage does not automatically deliver the best total cost. Compare inclusion rate, delivered magnesium, freight, flow, mixing behavior and the technical target.
Build the procurement file
Request the TDS, SDS and representative COA. Review assay method, agreed impurity limits, appearance, moisture, particle size, bulk density, packaging, storage and lot traceability. If reactivity is critical to the project, define the method and acceptance criterion before purchase rather than relying on an undefined marketing term.
Plan packing and import handling
Available packing options include 25 kg bags, 50 kg bags and 1,350 kg bulk bags, subject to grade and order confirmation. Buyers should consider warehouse humidity, dust control, bag handling, pallet configuration and container utilization. Mexico, Brazil, Chile, Argentina and Caribbean destinations may apply different import, feed-use and labeling requirements.
Validate in the complete ration
Premix compatibility and animal-nutrition decisions should be made by qualified formulation teams. Evaluate the selected grade in the complete mineral program and ration; do not infer guaranteed performance from MgO assay alone.
See the Magnesium Oxide product page and our 90%, 94% and 99% buyer’s guide. For a specification, sample discussion or destination-specific quotation, contact Winstar Ingredients.