Soil Health and Animal Health - Managing Micronutrients

Balance is a key word at NTS when it comes to the soil, but how relevant is it to animal nutrition? What similarities does the animal eating the grass or hay have with the soil from which this food was produced?

When we analyse soil tests here at Soil TherapyTM headquarters we often discuss how to ensure adequate trace mineral levels are achieved. Trace element deficiencies will have a flow on effect to production and ultimately herd health and it is usually the lowest concentration that sets the limit due to the complex interactions between the elements. To understand the importance of trace elements we can start with a look at single-celled organisms. Microbes are essential to life processes, such as digestion (in both the soil and an animal) and their metabolic function is highly dependent on the lack or over supply of trace elements. Every physiological process within that single cell is exquisitely controlled and each biochemical reaction is required for optimal functioning. If we extrapolate to multi-cell organisms like an animal or humans we still see the same inherent biological requirement for trace minerals as enzyme catalysts, it is just that higher life forms generally have a higher tolerance of deficiencies due to a larger margin for error.

In ‘Soil Fertility and Animal Health’, Dr. William Albrecht contends that reproductive function is often the first casualty when nutrition underpinning those biochemical mechanisms is deficient. Improved reproductive performance may represent increased calving rates for graziers or an increase in the number of laying days per year for egg producers.

In this article we will briefly touch on the two trace minerals and their deficiency symptoms in stock and soil and also investigate an animal-specific trace mineral. Copper and zinc both play important roles in animal metabolism and soil fertility while iodine is a non-essential element in higher plants but is vital for animals and humans.

Copper in the Soil / Plant- Resilience and Protection

Copper is the “protein micro-nutrient” and functions to increase the uptake of the ammonium form of nitrogen in plants. Ammonium nitrogen is essential for the reproductive phase of plants but its adequate uptake is also crucial in terms of maintaining the balance between ammonium-nitrogen and nitrate-nitrogen. This is critical nearing harvest as nitrates are known carcinogens and our food should ideally contain 3 parts ammonium to 1 part nitrate. Copper also plays a major part in chlorophyll production, sugar synthesis and root metabolism. This highlights just how essential a trace element can be- naturally plant health is seriously compromised without adequate chlorophyll, sugar synthesis and root growth. Crops deficient in copper may appear stunted and produce poor yields. Young leaves may be distorted and exhibit chlorosis while elasticity and strength in stalks will decrease.

Copper is an element linked to protection from fungal disease and is used in foliar sprays in orchards to control various diseases. There is an unfortunate tendency for overuse of this mineral for disease control. Once again balance is the key- an oversupply of copper can antagonize (limit the uptake of) phosphorus, iron, zinc, manganese and molybdenum, so it should never be abused. Not only can copper fungicides lift soil levels of copper beyond the 2 to 7 ppm which is considered ‘ideal’ but they can kill beneficial fungi in the soil. Soil food web analysis reveals that beneficial fungi have been seriously compromised in most of our agricultural soil and excess copper is a key player in the decimation of these important organisms.

Copper in Animals – Resilience and Protection

In animals copper is critical for iron transportation in the blood and formation of haemoglobin (notice how animals and humans mimic plants- chlorophyll and haemoglobin are very similar in both form and function). Copper is also required in the nervous system where it is associated with the formation of the myelin sheath (a fatty layer around nerve axons that allows the rapid transduction of nervous signals). Once again it also has a protective effect and is involved in anti-oxidant enzyme production. Copper is one of the elements commonly used in parasite control in organic agriculture. Deficiency symptoms include loss of wool crimp, anemia and poor reproductive rates. Again balance and ideal levels are important to remember as copper in high levels is toxic to animals. Dietary copper requirements vary greatly among different animal species but can be supplemented easily in a free choice lick situation.

Soil Zinc – Energy and Leaf Size

Zinc is the “energy micro-nutrient” and is essential for phosphorous uptake (phosphorus is the energy macro-nutrient and is needed for ADP & ATP production). Like copper, zinc plays a role in regulating plant sugar and carbohydrate transformation. Auxins, hormones which govern leaf size, are controlled by zinc levels. Desired zinc levels in the soil are around 10 ppm. Zinc deficiencies show as severe retardation of leaf and shoot growth resulting in small leaves and short internodes. The leaf, of course, is the solar panel which governs the efficiency of photosynthesis, the most important of all leaf processes. Zinc can be the most cost effective of all inputs because a few dollars invested can have a large impact upon yield is there is a major zinc deficiency.

Zinc – Sexual Health and Reproduction

Zinc is critical for animals and humans and is involved in cell growth and replication, sexual maturity and reproduction. Males should be well aware of the need for zinc as it is essential for prostate and testicular health. Zinc deficiency has also been linked to female reproductive cancers and should be supplemented at 25 mg per day (best if taken directly before bed). Hair and skin problems are also associated with zinc deficiency although these symptoms can be misinterpreted due to the wide range of pathogens, deficiencies and diseases that manifest as hair and skin problems. Ruminant requirements are usually satisfied by grazing green pasture however supplementation may be required on dry herbage.

Iodine – Thyroid Health and Reproductive Efficiency

Lastly we will look at an animal-specific trace element. Iodine is not required in significant levels in higher plants but is essential for animal and human health. The thyroid hormones (T3 and T4) regulate energy metabolism and iodine is an important constituent. Basal body rates are highly influenced by these hormones even right down to the passage of digesta. Iodine for the developing foetus must cross the placental wall as the developing foetus does not utilize maternal thyroid hormones. Severe deficiencies show as goiters and often high mortality in newborn animals. Pasture and weather patterns influence iodine availability and it has been suggested that rain leaches this element from soils. Once again requirements vary with animal.

As mentioned higher plants do not seem to utilize iodine in high amounts however marine plants have an ability to concentrate low levels of iodine found in seawater. Kelp in particular shows a high analysis of iodine and has proven itself beneficial as a stock supplement. Along with iodine it contains over 70 minerals and amino acids and this makes it an ideal supplement for when dietary intake is inadequate. Sea-Change Stock BoosterTM is a kelp based stock supplement that is available in three forms; a 2 mm grade and a micronised powder that can be added to feeding rations and licks and a liquid that allows the use of this gift from the ocean in water systems. Of course, kelp has long been recognized as a valuable fertilizer as well.

The book mentioned earlier, ‘Soil Fertility and Animal Health – the Albrecht Papers Volume 2′ by William A. Albrecht is a recent addition to the NTS bookshelf and is available now after a delivery from the United States. Dr. Albrecht made the case for an agricultural model based on healthy soil ecosystems rather than simplistic chemical inputs and this is a message that NTS has be promoting in Australia for the last 12 years.