Phosphorus (P) in animal diets as a driver of embodied P in animal products and net anthropogenic P inputs

One approach to address both the environmental and scarcity issues that occur with phosphorus (P) losses from human systems is to improve understanding of the P demands of bio-based products. Most P demand in the United States is driven by production of crops for animal feed and mineral P feed supplements for animals. In this research, we used the Commodity-Specific Net Anthropogenic Phosphorus and Nitrogen Inputs (CSNAPNI) model to (1) assess the contributions of individual feed products such as corn, soy, and mineral P supplements to the embodied P of animal products and (2) estimate net anthropogenic phosphorus inputs (NAPIs) for the contiguous United States for two animal P-intake scenarios. Results show that P supplements may contribute up to 30% of embodied P in pork and dairy products, up to 60% in chicken, and up to 75% in turkey. Other major contributors to animal product-embodied P are grains, which are responsible for around 60% of embodied P in pork and dairy products, at least 30% in chicken, and at least 20% in turkey products. Results also show that animal P intake is such a significant driver of anthropogenic phosphorus that a reduction of animal P intake by 25% could reduce NAPI to the contiguous United States by 30%. Considering promising research on methods to improve digestibility of both mineral P supplements and grain P in animal diets, these results are encouraging.

Automated summary

The study highlights the significant contribution of phosphorus supplements and grains in animal feed to the phosphorus content in animal products. Reducing animal phosphorus intake can have a substantial impact on reducing anthropogenic phosphorus inputs in the contiguous United States.