Evaluation of using magnetic nanoparticle attached phosphorus species as supplemental phosphorous source in broiler diet

Summary: Aluminum doped magnetite (Fe3O4) magnetic nanoparticle (MNP) has been used as an effective sorbent to remove phosphorus (P) species in poultry processing wastewaters. It was found that spent MNP contains approximately 13% of P by weight. A study was conducted to evaluate the potential of using spent MNP as a P source. A total of 240 one-day-old male broilers were randomly allocated to four dietary treatments and six replicate each for 18 days. Treatments consisted of 1) positive control (PC) with 0.45% nonphytate-P (nPP); 2) negative control (NC) with a reduction of 0.15% nPP; 3) NC with additional 0.075% of P from magnetic nanoparticle (NC + 0.075% P-MNP); and 4) NC with additional 0.15% of P from magnetic nanoparticle (NC + 0.15% P-MNP). Body weight and feed intake were recorded at day 7, 14, and 18. Three birds were randomly selected from each cage for Dual-energy X-ray Absorptiometry (DXA) scanning at d18. The liver, heart, and spleen were collected and analyzed for mineral content. Ileal digesta were collected from the rest of the birds for P digestibility analysis. Data were subjected to SAS using one-way ANOVA model with GLM procedure. The birds fed with additions of 0.075% and 0.15% P from MNP had an increased (P = 0.017) body weight gain at d8 to d14 compared to those with NC diet. Significant lower (P ≤ 0.008) body mineral density and body mineral content were observed in the birds with NC diet compared to those with PC, NC + 0.075% P- magnetic nanoparticle, and NC + 0.15% P- magnetic nanoparticle diets. In addition, the birds with NC + 0.075% P- magnetic nanoparticle and NC + 0.15% P- magnetic nanoparticle had similar body mineral contents and body mineral densities compared to the PC-fed birds, indicating P from spent magnetic nanoparticle has incorporated into the bone mineralization. No significant differences were found between the treatments for mineral residues (Al and Fe) in liver, heart and spleen samples. The ileal P digestibility of dry matter and P was not influenced by the presence of magnetic nanoparticle in diets. In conclusion, 0.15% P from spent magnetic nanoparticle could be efficiently and safely used to replace the same amount P from dicalcium phosphate in the diets for broilers.