LAUSR

Feed phosphates are included in swine diets to meet the requirements of P. Two products are predominantly used for this purpose, commercial monocalcium phosphate (MCP) and dicalcium phosphate (DCP). Theoretically, pure MCP should contain 26.5% P but commercial sources of MCP contain around 21 % P. The reason there is less P in commercial sources is that these sources are contaminated with calcium carbonate and other minerals. In addition, feed grade phosphates called MCP in reality is a mixture of MCP and DCP, which also contributes to the reduced P. To determine the complete composition of commercial MCP, seven sources of MCP were procured. All sources were analyzed for most common minerals that may be present in feed phosphates (Table 1) Results indicate that the composition of minerals is relatively stable among the different sources of MCP, indicating that the process to produce feed grade phosphates does not result in much variability. However, none of the commercial feed grade phosphates contained close to 26.5% P, which would be expected in a pure source.