Minerals for Dairy Cows

To fully maximise the benefits from feeding maize silage, adding minerals should be considered.

Maize silage has low levels of potassium, calcium, magnesium, sodium and phosphorus. Feeding maize silage can exacerbate mineral deficiencies such as magnesium and calcium which are already present in pasture. Dietary mineral supplementation should be considered during early lactation or if maize silage makes up more than 25% of the diet.

Requirements for trace minerals are similar when feeding maize silage or grazing pasture. A trace element supplementation or animal treatment programme should be routine one month before calving and four months after calving.

The table below gives mineral recommendations for herds feeding 25 - 40% of the diet as maize silage. For mineral recommendations specific to your farm, or for maize silage feeding levels above 40% of the dietary drymatter intake, contact your local animal nutritionist or veterinarian.

Mineral supplementation guidelines when 25 - 40% of the drymatter intake is maize silage  
Stage of lactation Limeflour Calcium (Ca) Magnesium Oxide Magnesium (Mg) Assalt Sodium (Na)
Pre-calving 0 40 0
Early lactation 60 - 150 40 - 70 15 - 30
Mid lactation 0 - 60 40 15 - 30
Late lactation 0 - 60 40 - 60 20 - 50