Evaluation of Struvite Recovered from Swine Wastewater as an Alternative Phosphorus Source in Broiler Feed

The objective of this study was to evaluate the feasibility of reutilizing phosphorus (P) recovered as struvite from swine wastewater as an alternative to commercial P sources in broiler feed. The recovered struvite was pre-treated as microwave irradiated struvite (MS) and incinerated struvite (IS) to reduce the NH4-N concentration in recovered struvite before application. A preliminary study on the growth performance and blood metabolites of broiler chickens was then performed to assess the effect of MS and IS by comparing with commercial monobasic dicalcium phosphate (MDCP, control). A total of 204 male Ross 308 broiler chickens (mean body weight (BW) of 80 +/- 5 g) were randomly allotted to each of 12 pens. The growth performance and blood metabolites analysis of broiler chickens showed no significant difference among the test materials (p > 0.05). However, the apparent total tract digestibility of crude fat was significantly higher in MS and IS treated groups compared to the control (p < 0.05). The digestibility of crude ash in control was significantly lower than that in MS (p < 0.05). The results suggested that P recovered from swine wastewater as struvite can be reutilized as an alternative P source in broiler feed without adverse effects on growth performance and blood metabolites through proper pre-treatment. To our knowledge, this is the first study to evaluate the potential of using struvite in animal feed. This study provides primary evidence for the safety and efficacy of using pre-treated struvite as an alternative source of P in animal feed and will encourage further studies with more rigorous design.