As I have stated in previous posts, proper mineral nutrition relies on a balance. This is critical to avoid mineral interactions. Mineral interactions can result in one mineral restricting the bioavailability of another. Thus, reducing the amount of that mineral absorbed by the animal. This can lead to deficiency.
One of the most common mineral interactions in beef cattle is the interaction between calcium and phosphorus. Generally, calcium and phosphorus levels are recommended in a ratio (Ca:P). Ideally, a ratio of 2:1 is targeted. Cattle can handle slightly lower Ca:P ratios, however when the ratio becomes inverted, or more phosphorus is provided than calcium, steer cattle can be at risk of urinary calculi. A prolonged period with a Ca:P imbalance in young cattle can interfere with bone growth and decrease overall performance.
Certainly the Ca:P ratio is important to monitor. In cases of high levels of Ca and P in the diet, other mineral requirements for magnesium, manganese, iodine, sulfur, iron, and zinc will all increase. Remember the key to proper mineral nutrition... balance.
Co-product feeds can be high in P. Thus it is important to balance the Ca:P ratio in co-product containing diets. Also, be aware if inclusion rates of co-products are very high that you may also be increasing other mineral requirements besides just Ca.
The relationship between copper, iron, molybdenum, sulfur, and zinc is another crucial mineral interaction. These minerals can all influence the bioavailability of each other. High levels of zinc, iron, molybdenum, or sulfur can all interfere with copper availability. Copper deficiency is one of the most common mineral problems across the country.
Selenium deficiency is a problem in Illinois. Selenium and Vitamin E are generally used in conjunction to supplement against Se deficiency. This is because both Se and Vit E work along the same lines in the body to prevent hydroperoxides. Administering Se and Vit E together is a good supplementation strategy to combat Se deficiency.
When formulating your mineral nutrition program it is crucial to be aware of these mineral interactions. Even if levels fall within the desired range, being on the high side for one mineral that interacts with a mineral that you barely meet requirement for can result in deficiency. If high levels of a certain mineral are hiding in the feeds or water source, an interaction may be occurring and the balanced mineral supplement may not be achieving its desired purpose.