Trace minerals play a valuable, but almost invisible role in the well-being of beef cattle. They are essential for good animal health status when the immune system is activated by disease.
Whether a single or combination product, trace minerals are needed for good immunity to improve vaccination take in cattle. University research has already proven once cattle meet their basic requirement for certain trace minerals, they have a better chance at good health. Of the several dietary minerals required by cattle, copper, iron, zinc and selenium are the metallic links to good immune function.
It is thought within cattle immune systems, these four minerals play a pivotal role as “on” switches in specialized proteins (enzymes), which in turn are activated antioxidants which destroy dangerous “free radicals” produced during a normal immune response against disease. Without sufficient levels of these essential trace minerals in the body to activate protective enzymes, free radical compounds would simply be allowed to multiple. As a result, they would oxide and destroy vital immune cells and thus could compromise or even shutdown the entire immune system.
When cattle consume, absorb or retain lower amounts of these trace minerals compared to their NRC cattle requirements (established dietary levels of copper, iron, zinc and selenium sufficient to meet all body functions with a small available reserve), they slip from adequate mineral status into marginal deficiency, which first reduces immune activities. This initial compromise to health occurs well before a reduction in cattle reproductive performance, and before moving into a severe mineral-deficient state that finally produces observed clinical symptoms in cattle.
When cattle immune systems are literally drained due to a reduction of mineral status, beef producers tend to observe a higher incidence of general viral and bacterial sickness of both cows and calves in their herd. This could include common respiratory and intestinal problems as well as a higher susceptibility to more infrequent disease ranging from coccidiosis to anaplasmosis.
Regardless of type, once any disease establishes itself in an immune-compromised herd, there is often a greater than normal proportion of afflicted animals, which lends itself to greater morbidity and possibly greater mortality. It also requires longer periods for these beef herds to recover from most disease challenges and to once again establish a clean bill of health.
In order to avoid beef cattle moving into a marginal deficient state in the first place, it is imperative to put them on a sound trace mineral feeding program.
Commercial trace mineral supplements can be purchased by most producers in one form or another and incorporated into their beef feeding programs to prevent “classic” or primary mineral deficiencies. However, many detected mineral deficiencies are “secondary mineral deficiencies” caused by dietary factors that severely affect the specific mineral’s availability to the beef animal.
For example, dietary copper can be bound by forage molybdenum, which renders the copper unavailable to the animal. Such deficiencies are solved by more specialized mineral-feeding programs which take into account essential trace minerals that are frequently tied up by dietary antagonists.
Healthy cattle should achieve adequate trace mineral status by consuming respective available amounts of mineral supplements that take into account both types of mineral deficiencies; based on recommendations, outlined by the NRC (National Research Council). Acceptable dietary levels in most diets are: copper (10 ppm, max. 100 ppm), iron (50 ppm, max. 500 ppm), zinc (50 ppm, max. 500 ppm), and selenium (0.3 ppm). Of these four elements, iron often is not necessarily supplemented in diets, because the amount of biologically available iron in most forages often exceeds the respective cattle requirement, making natural iron deficiencies quite rare.
Aside from putting a well-formulated mineral (with or without added iron) in front of the cows, daily mineral intake is one of the biggest factors that determine whether cattle achieve their essential trace mineral requirements. Therefore, the general mineral intake recommendation is to feed cattle mineral, so each beef animal consumes between 56-112 grams (two to four ounces) of salt-free mineral per day. If salt makes up at least 25 per cent of mineral, adjust mineral intakes, accordingly.
It is normal for daily mineral consumption to vary among cows. Furthermore, when new mineral is placed, consumption is usually higher than expected, but after a few days should return within given limitations. In contrast, producers should be concerned when mineral consumption falls outside of the recommended mineral intake guidelines (two to four ounces/head/day) for several weeks to a month.
There are many options to correct a mineral consumption problem. It is a common practice to mix 1/3 salt with 2/3 commercial cattle minerals to either increase or decrease the amount of mineral cattle are consuming. In recent years, adding distillers’ dried grains or dried molasses at four to five per cent of the mineral has also become routine to stimulate mineral intake. In many cases, when mineral consumption is high, it is a good idea to review the rest of the cattle diet and insure an overall balanced ration is fed.
Cattle that consume the proper amount of mineral with proper concentrations of available copper, iron, zinc and selenium allow these minerals to do their job, which leads to adequate immune function. As a result, cattle have better cellular and tissue integrity, greater antibody production and an immune complex that quickly responses to the invasion of disease. Unfortunately, we cannot see these microscopic benefits, yet we should see better production and economic rewards with a healthy herd. †