by: Stephen B. Blezinger

Part 3

In the last two parts of this series we've been discussing how to go about building your nutrition/supplementation program to be as cost effective as possible. In this last segment we will discuss the mineral component. We see articles about minerals all the time and in fact, mineral nutrition is probably one of the most researched areas in cattle feeding and nutrition. It is also still one of the most poorly understood and one of the most inconsistently managed – if it is managed at all. So the following will discuss not only assembling a nutrition program but also discuss some basic truths about mineral program use and management.

Over feeding/Under feeding – both are problems

Every producer requires a mineral program. There are no grass or grazing programs perfectly matched to the mineral requirements of cattle. Also, when other supplements are thrown into the mix, as is common, they are often formulated to include a mineral and vitamin mix of some type. In some cases these other supplements can carry all the mineral the herd may need, IF it is formulated correctly. So, it is totally feasible to create a supplement that supplies not only protein and/or energy but also the necessary minerals and vitamins as well.

Off-the-shelf mineral supplements seldom match your requirements very well. While many local feed suppliers will make some effort to provide a product that matches the local area to some degree, remember that every farm/ranch is an individual environment based on past and present management and thus can vary greatly in terms of the forage base upon which the mineral program is founded. Unfortunately, the availability of many mineral supplements is based totally on cost and the specifications have little relationship to what the actual requirements are.

Producers who supplement mineral will commonly provide a product of some type (loose, blocks, tubs) in addition to whatever their protein or energy supplement may be. The important factor here is to take into account not only the mineral being delivered by the forage base (from your forage tests you have run, as discussed earlier) but also the mineral content in your other supplement(s). Lack of supply and resulting mineral or vitamin deficiencies are commonly discussed along with the symptoms. However, overfeeding can be equally problematic and can create a whole different set of symptoms. Some of the minerals are more of a problem than others when is tomes to toxicity. For example, we often see problems in cows on winter pastures with Grass Tetany. Generally this is diagnosed as a magnesium (Mg) deficiency. This is not always the case though. Grass Tetany in many cases is not just caused by low Mg but an imbalance of the Phosphorus (P), Mg and Potassium (K) ratios. Winter pastures (wheat, oats, ryegrass) are typically very high in K. In some cases the high K can be as much a problem as marginal to low Mg may be. Also, producers often will also only supplement additional Mg when cattle are on winter pasture. This can be a problem since high Mg minerals are not terribly palatable and under consumption can be a problem. It generally makes sense to supplement some Mg all year round. This keeps the Mg status of the animal better and reduces the risk during winter pasture grazing periods. It also allows the producer to supplement lower levels of Mg during these periods which helps maintain adequate intake levels and supports the body's Mg status.

Trace minerals are likewise complex to supplement. High levels of Sulfur (S), Iron (Fe), Molybdenum (Mo) and Zinc (Zn) in the diet can depress Copper (Cu) absorption. High Calcium (Ca) and S levels can reduce Selenium (Se) absorption. All this said, it becomes obvious that in order to have a proper mineral program in place it is important to take all sources of minerals into account. This also includes water. So while we want to be sure we are meeting all the requirements it is important that we do not feed excessive levels either. So it becomes a matter of testing forages and gathering complete mineral information in supplements and test your water as well periodically. All these sources must be added together to quantify mineral intake as well as possible and compare this against the animal's requirements.

The animal's mineral requirements will vary depending on a number of factors including stage of production, breed, age, previous mineral status, etc. Of all the nutrient classes you will need to supplement, it's probably the most useful to recruit the help of a nutritionist in defining these supplemental numbers.

Mineral Supplementation Factors for Consideration

1)      Form – minerals can be provided in a variety of forms. If the producer is already providing a protein and/or energy supplement already, and feeding consistently it is simple to formulate the necessary minerals and vitamins into this mix. It will obviously add some cost to the product but in many cases, since some mineral and vitamin is commonly added already, adding amounts to bring these levels to a full supplementation level is pretty cost effective.

Other supplements such as tubs or liquid feeds can also be used to provide some or all of the necessary minerals. Liquids can be used to effectively deliver phosphorus, most or all of the trace minerals and vitamins. Calcium and Magnesium can also be delivered but require the liquids to be manufactured differently in a “suspension” form. This requires that specific ingredients be added to prevent non-soluble ingredients from settling out. Liquids manufactured in this form are not as common and are generally more expensive.

If supplemented alone, minerals should be provided in a loose free-choice form. The typical red, yellow or white blocks are not good mineral sources and are generally largely salt. Trace mineralized salt is also generally a poor source and not a complete mineral supplement at all. To emphasize this: THE USE OF RED, YELLOW, OR WHITE “MINERAL” BLOCKS DO NOT CONSTITUE A MINERAL PROGRAM. Yes, cattle will eat them but it is mainly because they like the salt.

2)      Intake – proper intake is critical. I am not a fan of low intake products, generally because they are not formulated to deliver the necessary amount of mineral at a one to two ounce per head per day level. Plus, at these low levels even a slight deviation from these target intakes result in excessive variation which allows the animal to miss the intake target. A three to four ounce intake level, while still low, better allows for proper mineral formulation as well as inclusion of other components such as medications, fly control, ionophores, etc. It also allows for the inclusion of carriers such as a grain component which can help stabilize intake, etc.

Since intake can vary, never assess consumption levels over the course of a day or week. You will get a better feel for intake levels over the course of a month and better, over a quarter. It is highly recommended to put out mineral the same time every week in a given pasture and actually write down the amount eaten, calculating what the consumption level is per head per day. If cattle are not eating enough mineral you need to make adjustments.

Consistent intake, after proper formulation based on other supply and animal requirements, is the most important characteristic of a well-designed mineral supplement. Mineral intake can vary significantly under the best of circumstances so it is important that the formulation focus on intake consistency as much as possible. Other issues can also affect intake. These can include:

a)      Previous mineral program – if you had a poorly designed product or one not well matched to your forage base or cattle requirements you can expect intake to be considerably higher than the target until cattle reach some level of mineral status equilibrium.

b)      Palatability of the product

c)      Salt content – too much or too little sale can have negative effects.

d)      Additional salt feeding – some producers feel it is necessary to provide additional salt along with their mineral. This is seldom needed. First, because cattle do not have that great of a salt (sodium (Na) and chlorine (Cl)) requirement. Second, most minerals come with more than adequate salt levels to address the Na and Cl needs. Third, in almost every case, the offering of salt will reduce mineral intake and in most cases that is not desirable from a nutrition standpoint.

e)      Feeder placement. Proper placement can be a key to proper intake. Feeders placed close to water, resting areas, hay rings – anywhere that cattle frequent or congregate will normally see higher intakes. To reduce intake, move feeders away from these areas. Monitor intake and adjust placement accordingly.

f)      What else do cattle have access to? Mineral intake will vary according to quality and quantity of forage as well as the availability of other supplements. If cattle do not have access to plentiful or good quality forage, intake will be higher. If they have plenty of good grass or hay as well as other supplementation intake will likely be low, thus the reason for accounting for all forage/feed/supplement intake opportunities and the nutrient content of each.

3)      Trace mineral sources – sources of trace minerals have been debated for years. The two primary sources include inorganic (oxides, chlorides, sulfates) and organic or chelated sources. Most if not all minerals contain trace minerals that are largely inorganic. And research over the last 20 years or so have guided mineral manufacturers to use predominantly sulfate sources for this portion. Generally you will find Cu, Zn and Manganese (Mn) supplied as sulfates. If iron is added (generally not required in cattle formulations) it is also added as a sulfate but can also be found as an oxide where manufacturers want to add the red color to a mineral (also unnecessary). Cobalt (Co) is commonly added as a carbonate but can be found in a sulfate form. Selenium is generally added as sodium selenite or selenate. One note here, the amount of Se that can be fed is regulated by the FDA (3 mg/hd/d). The form used is not regulated. Iodine (I) is an exception and is often added as EDDI or Ethylenediamine dihydroiodide, which is considered organic. It can also be found as Ca or K Iodate which is considered inorganic. Some oxide forms are still used by some manufactured but oxides are considered to be the most poorly absorbed. The sulfate forms are considered to be the standards for inorganic trace minerals.

Organic or chelated forms are another story. There are at least 10 different organic trace mineral (OTM) suppliers on the market providing a variety of trace mineral combinations. Organic trace minerals are defined as molecules where the metal fraction (Cu, Zn, Mn, Co, I, Se) has been bound to an organic fraction (known as a ligand) of some type. This may be an amino acid (i.e. methionine, lysine, etc.), a peptide (two or more amino acids), a carbohydrate (i.e. one or more sugar molecules) or an organic acid. The function of these OTMs is to protect the metal from being bound to another atom or molecule in the rumen and becoming unavailable for absorption in the small intestine. But in addition to the protection they provide, these molecules must also be able to release the metal so it can be picked up at the intestinal wall and transported into the body.

As mentioned there are multiple suppliers for OTM's. The question that commonly is asked is “which is the best?” The answer to that is “nobody really knows.” There are a couple of companies which, over the years, have generated a great deal of research to show how effective their product is. These comparisons are normally made against inorganic sources. Few, if any studies have been conducted which compares products to one another. This is not surprising since no one wants to fund a study where their product might not come out the best and run the risk of those study results finding their way to the marketplace. Nutritional research is simply too variable. This and the fact that the actual absorption and utilization of these products is based on a fairly long list of factors which will be covered at another time.

Overall extensive, ongoing research has shown that OTM's should be included in a mineral program as probably 25 to 33 percent of the overall trace mineral supply. The improved availability of the TM's to the animal have shown positive effects especially in improved reproduction and health benefits. The exact source to use is debatable although some nutritionists are considering that there may be a benefit to adding a blend of OTM's to try to broaden the spectrum somewhat.

4)      Additives – a variety of additives can be formulated into mineral supplements. This can include antibiotics such as CTC, ionophores like Rumensin® and Bovatec®, yeast products, bacterial cultures, enzyme preparations, fly control and so on. The combinations are extensive but, in some cases, are regulated by the USDA or FDA.


From this you can see that the mineral supplement component of your feeding and supplement program can be somewhat complex but like anything else is dependent on your base forage program and the type of operation you have. Some research and pencil pushing and assistance from a qualified nutritionist can help you greatly at keeping your costs down and building the best program possible for your operation.

Dr. Steve Blezinger is a management and nutritional consultant with an office in Sulphur Springs, TX. He can be reached at sblez@verizon.net or at (903) 352-3475. For more information please visit us on at www.facebook/reveille livestock concepts.

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