Magnesium cannot be stored efficiently in the body; therefore, cattle depend on daily dietary intake.
Primary causes:
1. Low dietary magnesium
Occurs in:
· Rapidly growing pastures
· Spring grass
· Winter wheat pasture
2. Reduced magnesium absorption
Due to:
· High potassium intake
· High nitrogen fertilization
· High calcium intake
· Low sodium
3. Increased magnesium requirement
Occurs in:
· Early lactation
· Stress
· Cold weather
· Transport
3. Predisposing Factors
Risk increases with:
Animal factors:
· Older cows
· Lactating cows
· High milk producers
· Beef cows more than dairy in pasture systems
Nutritional factors:
· Lush green pasture
· High potassium grass
· Heavy nitrogen fertilization
· Low fiber diet
· Low magnesium intake
Environmental factors:
· Cold weather
· Rain
· Sudden pasture changes
· Stress