Last year, we had many discussions and questions about supplementing minerals. Here is some information on this topic from UGA Extension Animal Scientist Dr. Lawton Stewart:
I have heard several comments that producers are cutting P out of their mineral, because they are using poultry litter as fertilizer. Although there is potential to improve the P levels in forage with little, assumptions are being made on the ability of the plant to make the P available to the animal. This is one of the examples of how we need to make sure we’re cutting cost and not cutting corners in our production system.
In fact, some producer may cut minerals out all together to help cut cost, because performance does not appear to change. Short term maybe, but the long term consequences may be more costly. If you look at a cow/calf annual budget, minerals represent only about 3.5%; a very small cost to insure health and performance. The greener pasture we’re seeing may reduce the feed bill, but we need to remember many forages in the Southeast are deficient in several minerals. Although minerals represent a small cost in total budget, we can cut some extra expenses by taking a second look. We can learn a lot by getting our forages tested and reading the mineral tag.
Forage Testing is the cheapest initial investment you will make. We must have a starting place if we want to know what minerals, and how much we need in our minerals.
- Calcium and Phosphorus – These are two macro minerals that need to be addressed together due to their interaction in the biological processes. On well managed pastures, forages are typically close to meeting the requirement of brood cows, but are deficient for growing cattle. However, almost as important as the quantity of these is their ratio. The ratio of Ca to P needs to be greater than 1.5:1.
- Sodium and Chlorine – More commonly referred to as salt, these minerals are the only ones cattle will crave and need to be offered daily.
- Magnesium – This is a crucial mineral when cattle are transitioning into and during lactation. Generally, extra Mg is only needed during this lactation while grazing lush pastures. Often times, producer do not realize they are feeding Mg unnecessarily through the summer.
- Sulfur – Although S is essential, it is not usually limiting in the diet. However it may be present in mineral mixes due to inclusion of other minerals as sulfates. The concern with S is its antagonism with copper, selenium, and the B vitamin thiamin. Therefore, it sometimes is necessary to feed additional copper and selenium to compensate this antagonism.
- Micro minerals – These mineral needed in smaller amounts such as copper, zinc, and selenium. Most forages are deficient in these minerals and need to be offered as a trace mineral pack.
Read the mineral tag
- We can learn a lot by reading the mineral tag. Usually, the mineral company makes mixes to fit general needs. Some of these may fit your operation; however, there may be times your’re paying for ingredients you don’t need an/or not getting what you need.
- Check for the right mineral levels. Going back to our forage test, make sure you are getting the appropriate levels of each mineral and Ca:P ratio. If a supplement is being used, make sure you consider the mineral content. For example, if distiller’s grains or corn gluten feed is being utilized, P should be adequate, but Ca should be supplemented to maintain the proper Ca:P ratio.
- Look for additives. Often additives such as ionophores (Rumensin, Bovatec), antibiotics (chlortetracycline, GainPro), and fly control compounds (IGR) are administered through mineral mixes. Although these may improve performance, they may not be wanted in your operation and come at additional cost.
If the local feed store doesn’t provide the mineral that fits your production system, many will work with you to formulate a custom mix to provide the nutrients you need. The table below presents an example of a free choice minereal for lactating cows grazing in bermuda pastures. Remember, our goal is to cut cost and not corners to survive in the cattle business. For a complete description of both macro and micro please refer to the UGA publication Mineral Supplements for Beef Cattle.