Don't forget to mineral feed while on pasture

By Gary Sliworsky
OMAFRA Rep.

The weather has finally smartened up and the cattle are out on pasture. Let’s not forget the importance of mineral feeding while on pasture. Calf growth, cow reproductive status and general health are all influenced by the intake of adequate amounts of salt and mineral. It appears often that the definition of “free choice” mineral is your “free choice” on whether or not to buy mineral.
Pasture mineral feeding studies show interesting results. One trial measured mineral intake of the beef cow. Believe it or not, the range of consumption per cow per day varied form 0 ounces to 40 ounces intake.
Given this variability, consider the following guidelines when choosing your mineral program for pasture. Please note that minerals are sold by proportions of calcium to phosphorous to magnesium. Example: a 20:10:6 tag guarantee means 20% calcium, 10% phosphorous and 6% magnesium. Often this will be shortformed to “I feed a 2:1 mineral with 6% magnesium”.
Following are some considerations when providing mineral on pasture.
Use sheltered mineral feeders and supply quantities that will last no longer than 5 days.
Some producers mix a dairy premix (usually salt free, and often higher in trace minerals and vitamin levels than :free choice: cattle minerals) and cobalt iodized salt, at a blending rate of 1:1 salt/premix or 1:2 salt/premix depending on pasture conditions and water availability.
Choose the mineral suitable for your pasture type. Grass based? Use a higher calcium mineral like 3:1 or 2:1. Mixed legume/grass? Use a balanced mineral, typically 2:1 or 1:1. Heavy legume? Consider a 1:2 mineral.
Evaluate the magnesium levels required. Normally a 4% magnesium content mineral is adequate but in the case of fast growing grass pasture, higher levels may be required to avoid grass tetany.
The salt content of the mineral offered usually drives mineral intake. Cattle have a natural physiological requirement for salt, so don’t offer salt separately. Most cattle salt and mineral needs are met with an intake of about 2-3 ounces of a salt/mineral mix per day. If conditions warrant additional salt, consider offering it in block form.
As with all animal nutrient requirements, have a qualified nutritionist review your pasture feeding and mineral program.