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Over 90% of South African soils are deficient in the mineral phosphorus. The country’s warm, dry climate contributes to low levels of organic matter, which in turn limits phosphorus availability to animals. The phosphorus content of pastures is directly influenced by soil phosphorus levels and is closely linked to the protein content of the grass – when protein levels decline, phosphorus levels typically drop as well.
Veld grass generally contains between 0,3 and 0,6g/kg of phosphorus on an ‘as-fed’ basis, while fertilised hay contains approximately 1 to 2g/kg. However, only 65% of this phosphorus is in fact available to the animal. As a result, phosphorus is one of the most essential and widely recognised minerals that must be supplemented in the diets of grazing livestock.
Functions of phosphorus
Phosphorus is vital for energy metabolism in animals, facilitating the conversion of energy from feed or grazing into a form the body can utilise. It is a key component of cell membranes, where it helps regulate cell permeability. Over 80% of the body’s phosphorus is stored in the skeleton and teeth, highlighting its importance in these structures. Phosphorus also plays a crucial role in maintaining the pH balance within body cells and the rumen of ruminant animals.
Role of phosphorus in ruminants
Phosphorus is essential for the optimal functioning of rumen microbes, which are responsible for digesting roughage and synthesising microbial protein. These microbes also produce the enzyme phytase, which helps release phosphorus from plant material, making it more available to the animal.
Ruminants mobilise phosphorus from bone reserves and circulate it back to the rumen via saliva. When skeletal phosphorus stores are depleted, less phosphorus is mobilised, reducing its availability in the rumen. As a result, phosphorus must be regularly replenished.
Given its vital role, phosphorus deficiency negatively affects roughage digestibility, as well as the absorption and utilisation of nutrients, particularly protein and energy. This leads to a range of performance issues including reduced appetite, slower growth, compromised immunity, and decreased fertility and milk production. Affected animals may also develop pica, a condition marked by the chewing or ingestion of foreign objects such as bones, poles, wires, stones, or soil (see the photograph). Blood serum phosphorus levels below 1,3mM are typically indicative of a deficiency.
Actual phosphorus requirements
Phosphorus requirements vary according to the stage of production and the animal’s growth rate. A 450kg beef cow needs approximately 7g of phosphorus per day for maintenance, 3g for foetal development, and 1g for each litre of milk produced. Feedlot steers require around 7g of phosphorus for every kilogram of live weight gain per day. When comparing phosphorus intake from grazing to the actual requirements, large livestock typically need an extra 6 to 12g of phosphorus daily, while small stock require an additional 1 to 2g per day.
Phosphate supplementation is most effective when animals receive sufficient energy and protein. This makes phosphorus supplementation particularly valuable on green summer veld, where energy and protein levels are naturally higher. During winter, animals that are supplemented with adequate energy and protein also benefit from added phosphorus, especially during periods of high production, such as growth, late pregnancy, and lactation.
Supplementing phosphorus through phosphate licks is, therefore, a critical management practice for progressive livestock producers. These licks can be home-mixed by combining a phosphate lick concentrate – typically containing 12% phosphorus – with an equal quantity of salt, or they can be purchased as ready-mixed products containing 6% phosphorus. The recommended daily intake is 100 to 200g for large stock and 20 to 40g for small stock.
However, two common challenges with phosphate licks are poor palatability and vulnerability to rain. Phosphate is unpalatable, which may lead to insufficient intake, and licks exposed to rain can be wasted or lead to lower consumption. Both under-supplementation and product loss can have serious financial implications for livestock producers.
In response to these challenges, the livestock feed industry in South Africa has long used spray-dried molasses by-products. Royal Eswatini Sugar, based in Eswatini, has produced large quantities of CMS (condensed molasses solubles) as a by-product of alcohol production for many years. A recent initiative investigated the feasibility of diversifying by spray drying CMS for use in the livestock industry. This led to the establishment of a dedicated CMS and related product drying facility in Eswatini. Notably, this facility uses wood waste (wood chips) from a sawmill as its energy source to dry the CMS, offering a cleaner, more environmentally friendly and sustainable alternative to coal.
The CMS is spray dried onto a specific lime-based carrier to create Ecovite Drimol, a fine, molasses-based powder. Thanks to the unique spray-drying process and carrier, Ecovite Drimol possesses unique chemical and physical properties. It significantly enhances palatability and acts as an effective binder, protecting lick supplements from rain damage.
Ecovite Drifos P12 and P6
Ecovite Drimol forms the basis of two further products: Ecovite Drifos P12 and Ecovite Drifos P6. These formulations combine Ecovite Drimol with high-quality monocalcium phosphate, macrominerals, trace minerals, and, in the case of Drifos P6, salt. The phosphorus is presented in a highly absorbable form in the correct ratio of minerals (calcium, magnesium, and sulphur) while the product also contains a complete range of trace minerals. The monocalcium phosphate source is highly water soluble, ensuring optimal availability for rumen microbes.
Ecovite Drifos P12 is designed to be mixed with equal parts salt to form a weather-resistant lick containing 6% phosphorus, while Ecovite Drifos P6 is pre-mixed for convenience. Both options form a protective layer when exposed to moisture, safeguarding the lick from rain and wind.
The licks are highly palatable, promoting adequate intake. They can also be offered in block form by adding 10% water and compressing the mixture into appropriate containers. Importantly, these products are free of urea, non-protein nitrogen (NPN), growth stimulants, and medications, making them safe for all grazing animals, including horses and game.
In summary
Phosphorus plays a vital role in the productivity and profitability of livestock farming enterprises, significantly influencing both production and reproduction. Cutting back on supplementation of this essential mineral is shortsighted – phosphorus remains one of the most worthwhile investments livestock producers can make in their herds.
Ecovite Drifos P12 and Drifos P6 offer reliable, high-quality phosphate supplementation, helping producers meet their animals’ nutritional needs with confidence. The Ecovite range is proudly distributed by the Feedtek group.
Ecovite Drimol (V34430), Ecovite Drifos P12 (V35078), Ecovite Drifos P6 (V36310) – Act 36/1947.
For more information or to find your nearest Feedtek agent, visit www.feedtek.co.za, email info@feedtek.co.za, or call 086 111 5362.
