Mineral Deficiencies

magnesiumMineral Deficiencies


Macro minerals and trace minerals are needed year round by livestock for optimum production, health and fertility.


The Importance of Minerals in livestock

Adequate intake of minerals is critical for livestock, either through pasture consumption or supplementation. The role of supplementation is to bridge the gap between what the pasture provides and the animal’s requirement. Requirements vary depending on the animal and stage of growth/lactation.


There are over 60 elements found in soils that are known to be taken up by plants. For animals, there are 27 essential minerals. Essential minerals are required for maintenance and to support adequate growth, reproduction and health.


How do we know what is lacking in an animal’s diet?

Soil tests and pasture samples tend to provide the most reliable information. Soil samples, particularly, can reveal underlying key nutrient deficiencies and will tend to show patterns for various districts. Both blood and dung samples have limited use. Dung samples have only been calibrated for certain parts of Australia for limited nutrients (phosphorus and protein) and blood tests may provide inaccurate information, for example, a nutrient such as phosphorus can be mobilised from the animals reserves during periods of deficiencies and may therefore show up as adequate in a blood sample when the dietary phosphorus is actually below the animal’s requirement.

One key benefit of a soil test (and a water test is useful for this also) is sodium/salt level

Sodium is one of the most important elements that will impact on supplement intake and is usually the reason why an animal will over or under consume a supplement. This issue occurs with both loose supplements and lick blocks.


Livestock with access to underground water generally have adequate levels of salt/sodium in their diet due to the higher concentrations of salt in underground water. Therefore supplements containing the slightest bit of salt may not be palatable in these cases. Lick blocks generally have 10% salt or more and are often not eaten by cattle/sheep on bore water.


Minerals are still required and still of benefit, just because an animal isn’t eating a supplement doesn’t mean they don’t require those minerals, it’s simply that the supplement is not palatable enough. When livestock aren’t consuming their recommended intake levels, then adding a protein meal, molasses, grain (or sometimes salt) will increase intake to required levels. Salt can actually be used to slow down or increase supplement intake depending on the animal’s sodium status.


Offering salt prior to supplementation is recommended to gauge salt requirements. Satisfying a salt craving will save on supplementation costs and identify if salt is not required or unpalatable which assists us to guide you to the correct option for achieving effective mineral supplementation to help increase growth and fertility.


Like the soil, single elements are rarely independent or self-sufficient in their role in body processes as they often interact with and influence a number of other elements.


Interaction between minerals can affect digestion and absorption and single element approaches are often dangerous (maybe toxic) or cause a flow-on issue elsewhere. For example, administering copper on its own can induce a zinc deficiency and therefore suppress the animal’s immunity – increasing the animal’s vulnerability to disease or infection (zinc is a key driver of the immune system). High copper levels in water can cause an iron deficiency which, long-term, may result in ‘mysterious’ livestock deaths.


The level of iron, copper, zinc, cobalt, manganese, iodine and selenium found in feed materials is often too low to meet production requirements and so must be supplemented. (Source: The Minerals Directory, 2005.)


Phosphorus is one of the most important minerals in animal nutrition and is essential for appetite, efficiency of feed utilisation, bone growth and fertility.


To ensure the maximum response to phosphorus supplementation, MegaMin Extra Phosphorus and MegaMin Extra Phos 8 are formulated to provide calcium, sulphur, manganese and copper.


Why Sulphur is important?

  • Sulphur assists in detoxifying prussic acid found in forage sorghum. In addition, forage sorghum also lacks sulphur and salt.
  • Sulphur stimulates bacteria and fungi to assist the breakdown of fibre in the rumen.
  • Sulphur is essential for rumen health and the formation of amino acids – the building blocks of protein. Sulphur deficiency can reduce rumen microbe activity and lead to poor growth.
  • Sulphur is a key nutrient for wool growth.
  • Sulphur can assist with parasite control. Trials have shown a substantial increase in the level of natural resistance to ticks for cattle fed additional sulphur.


Why Phosphorus is important

It is well known that phosphorus deficiency can result in poor growth rates and lower fertility, and that supplementation is critical in areas where the soil is low in phosphorus.


Importantly, phosphorus can also be a major limiting nutrient when there is plenty of lush green feed during Spring or a wet season.


Phosphorus is required to support every energy process and vital functions in the body. When pasture quality improves, livestock grow faster or produce more milk.


This increased production is a result of increased ‘energy cycles’ in the animal which subsequently results in an increased requirement for phosphorus. During times of lush green feed, there is the opportunity to maximise stock performance by supplementing with additional phosphorus.


Why Magnesium is important

Magnesium is absorbed in the rumen and is the second most limiting mineral for stock grazing lush green pastures and winter forage. Lush green fodder passes too quickly through the rumen to allow adequate absorption of magnesium, which can lead to ‘Grass Tetany’.


Plant uptake of magnesium may also be reduced in the cooler months, increasing the need for supplementation. Magnesium stored in the body is not rapidly available so animals are reliant on daily intake, particularly during ‘high risk’ periods.


  • Magnesium may aid in reducing stress during weaning, sales, shows and transport and assist with meat quality.
  • Lack of magnesium can significantly reduce milk production.
  • Because mature fodder has a higher magnesium level in the stem, it is recommended to give animals access to roughage and legume hay during high risk periods for grass tetany.
  • Assists with calving and lambing