Phosphorus is an essential component in the makeup of life on Earth. Not only is it a building block in growing healthy, strong plants, but it is also an important building block for humans and animals as well; most notably, phosphorus aids in a variety of cell functions to build strong bones and teeth, but it contributes to many other biological processes. As such, phosphorus is a key ingredient in animal feeds, namely Monocalcium Phosphate (MCP) and Dicalcium Phosphate (DCP).While only about 5% of global phosphate consumption goes towards animal feed production, the production of phosphate animal feeds plays a critical role in maintaining livestock health and overall food security. And with the demand for phosphate feed on the rise, the efficient production of such products will become increasingly important.
Phosphorus used in animal feed is first mined in the form of phosphate rock. In order to separate the phosphorus from the surrounding undesirable material, such as sand and clay, the phosphate-bearing ore must go through a beneficiation process. As phosphate rock deposits vary considerably in their makeup, the beneficiation process can differ greatly from one deposit to the next.
Once the phosphate ore is dried, it can be reacted with sulfuric acid to produce phosphoric acid. Phosphoric acid is a versatile material, used in the creation of many products, but it is most commonly used in the production of phosphatic fertilizers and animal feeds.MCP and DCP are created by reacting the phosphoric acid with calcium carbonate and granulating the resulting material. It is worth noting that animal feed was not always (and sometimes still isn’t) granulated, but granulation has proven to add significant value to the end product; a granular feed is much more easily handled, provides a more uniform product, and offers significantly less dust.
Why are Phosphate Feed Additives Needed?
Vegetable feeds typically contain only 30% of the phosphorus that livestock and poultry need. Even then, only half of this amount is absorbed. Yet, phosphorus is a vital ingredient for life.As the industry trade body, the IFP, explains, “The high chemical reactivity of phosphorus means that it only occurs in nature combined with oxygen or other elements in the form of phosphates. Main phosphate sources are of plant, animal and inorganic origin, containing varying quantities of phosphorus in several different chemical forms.”As most of these forms are not easily absorbed, a phosphorus feed additive is often required.
What’s the Difference Between DCP and MCP?
The extra effort taken to produce MCP makes for a better final product.MCP is highly soluble, allowing for increased flexibility in diet formulation. It is also more easily digested by farm animals, meaning that less of the feed additive is wasted and it has less impact on the environment from run off.Anhydrous DCP has a particularly low level of phosphorus digestibility. This is in contrast to the high intake from MCP derived from DCP via the HCI production process. This method produces a feed additive of good purity and optimal phosphorus concentration.Research comparing the various inorganic forms of phosphate feed additives was recently published in the Spanish Journal of Agricultural Research (pdf). Among other findings, this study found that in chicken diets up to the age of day 21, “ … growth response was lower when anhydrous DCP was included in the diet as compared to MCP … [there was] higher P availability in purified grade MCP diets than in DCP diets … [and that] P in the anhydrous DCP form is less available for poultry than the hydrated salt [mono-sodium phosphate].”