Are you looking for a mineral this spring and summer? If so, be prepared to navigate through an array of commercial options. Differences exist in the concentration of the macro and trace minerals, in vitamin content, the presence or absence of salt, anti-caking and fly control technology and in suggested daily consumption targets. Unfortunately, when faced with making such a difficult choice, many producers rely on price as the determining factor and often end up with a mineral that does not meet the requirements of their cattle. What I would like to do with this column is focus on understanding the mineral tag and hopefully point out why some minerals are better than others, even though they might be more expensive.
The first step that I take when evaluating a mineral tag is to look at the expected daily consumption. This will vary between products. For example, some minerals list expected daily consumption at 90 grams per head per day (i.e. 28 grams equals one ounce); others indicate 100 or 125 grams per head per day. It makes sense that if two commercial mineral products differ in expected daily consumption, there should also be differences in the concentration of individual minerals, particularly if they are targeting the same daily intake of that mineral(s). The problem is not all companies target the same daily intake for minerals such as copper. It is possible, however, to make such comparisons with knowledge of expected daily mineral consumption, a concept I will expand on shortly.
Next, I scan the tag for the concentration of macro minerals, particularly calcium, phosphorus and magnesium. It is important to recognize that for the macro minerals, your mineral program should be designed to supplement the natural mineral content of your forage program. Most of the common forages fed to spring calving and breeding cattle provide a significant proportion of the animal’s calcium, phosphorus and magnesium requirements. For example, cows on alfalfa-based feeding programs likely get all the calcium they require from their diet. However, those on native or tame grass programs will likely require supplementation.
On the tag, these minerals are listed as a percentage of the total weight. In some cases, calcium concentration is twice that of phosphorus (i.e. 2:1 minerals) and in other cases, there are equal proportions of calcium and phosphorus (i.e. 1:1 minerals). Phosphorus is a particularly important mineral for breeding cows. However, the choice between a 2:1 and a 1:1 mineral will often come down to the nature of the spring forage program and the need for calcium supplementation as discussed above.
Magnesium is also an important mineral for breeding cows and is often deficient in lush spring pastures. If you are looking for a mineral fortified with magnesium, recognize that commercial minerals vary widely in magnesium content, typically ranging from two to eight per cent. Most minerals formulated for breeding cows on pasture contain at least three per cent magnesium.
Following the macro minerals, the tag will list the trace minerals or those minerals required by the animal in very small amounts. These include copper, zinc, manganese as well as several other required minerals. Mineral concentration is listed as milligrams per kilogram (mg/ kg). Again, you will find considerable variation in the concentration of specific trace minerals between different commercial products. For example, copper concentration might range from 1,500 to 3,200 mg/kg. To determine what each mineral product is actually supplying, it is important to check concentration against consumption. For example, animals consuming 90 grams (i.e. 0.09 kg) of a mineral with 1,500 mg/kg of copper will consume 135 mgs of actual copper (i.e. 1,500 X .09 = 135 mg). A mineral with 2,500 mg/kg of copper consumed at the same level will supply 225 mg of copper per day (i.e. 2,500 X .09).
This example illustrates two important points. First, with all things being equal, the mineral with 1,500 mg/kg of copper should be cheaper than the one with 2,500 mg/ kg. Secondly and more importantly, the mineral with the higher copper concentration, while more expensive, is much more likely to meet copper requirements of spring- calving beef cows, particularly if there are complicating factors such as high sulphate levels in water used for the cattle or elevated molybdenum levels in forages. Similar calculations can be made to compare commercial minerals for other trace minerals such as zinc or manganese or even for the fat-soluble vitamins (A, D and E).
There are several other factors to consider when choosing a mineral. One of the most important, particularly for cows before and following calving, is the type of trace minerals used in the formulation (inorganic vs. hydroxy vs. chelated). Chelated and hydroxy trace minerals are absorbed more efficiently and as such can be strategically used to correct deficiency situations and associated reproductive issues. Other factors to consider include the presence or absence of salt and specialty ingredients such as garlic or other chemicals for fly control.
As you can see, there are many factors to consider when making your choice. The decision is even more difficult when regional deficiencies in soil selenium or copper content are present or when mineral imbalances result in secondary deficiencies. In such cases, consulting with a nutritionist or veterinarian who knows your area and operation can help you select the most appropriate commercial mineral or, if necessary, design a custom blend.