With phosphorus prices very high, find out ways to reduce the amount of added phosphates in some feeds
Phosphates, such as mono- and dicalcium phosphate, are major sources of phosphorus (an essential nutrient that does not exist in large enough quantities in common raw materials) for most animal feeds throughout the world.
About 15 years ago, phosphate prices doubled, almost overnight, as phosphate mines were found to be near depletion, and industrial phosphorus was diverted to fertilizers as manure no longer contained enough phosphorus.
Now, the price has doubled again, mostly due to the war in Ukraine, where the majority of fertilizers was coming from. I read somewhere that pig manure in the U.S. is now being priced rather tastily (pun intended) even with limited phosphorus in it (plants need lots of phosphorus, as well). In the face of almost prohibiting phosphorus prices, I offer the following to reduce the amount of added phosphates in some feeds.
Reduced dietary specifications
Under normal conditions, most diets are slightly over-formulated with phosphorus to allow for a safety margin. In my commercial experience, using the current NRC requirements as feed formulation specifications has always given me satisfactory results. Based on my research work as a master’s graduate student at Kansas State University, I believe NRC estimates are rather inflated especially for market-age pigs. Below is my own set of phosphorus specifications for low-phosphorus pig diets (use at your own peril). You may notice that the amount shown for 80-120 kg pigs is roughly equal to what already exists in a typical corn-soy formula. Nevertheless, one should formulate using digestible phosphorus when diverting from corn and soy as the main ingredients.
Category | Total P (%) |
Growing pigs (kg) | |
< 10 | 0.60 |
10-20 | 0.50 |
20-50 | 0.40 |
50-80 | 0.30 |
80-120 | 0.20 |
As total phosphorus is reduced, calcium should be lowered as well. In general, the ratio of calcium to total ratio should not exceed 1.2 to reduce the risk of excess calcium binding phosphorus. Most animal feeds contain already excess levels of calcium (limestone is really inexpensive).
Finally, adding phytase and certain organic acids are also ways to increase phosphorus availability to the animal, but these are topics for other blogs and have already been discussed in depth.