PSVII-4 Potential Value of Turkey Litter Ash and Dried Swine Lagoon Sludge as a Phosphorus Source for Growing Pigs

The objective of this study was to evaluate turkey litter ash (TLA) and dried swine lagoon sludge (SLS) as alternative recycled sources of phosphorus. Analyzed concentrations (as-is basis) of Ca, P, and Na were 8.31, 3.98, and 0.70, respectively for TLA and 5.81, 4.31, and 0.12 for SLS. Fifty-six individually housed pigs (BW of 34.92±0.29 kg) were blocked by initial BW and randomly allocated within block to 1 of 7 treatments. Treatments consisted of a negative control diet (NC; 0.50% Ca and 0.12% available P (40% of requirement), NC plus 0.075% P from either monosodium phosphate (MSP), TLA, or SLS, and NC plus 0.150% P from either MSP, TLA, or SLS. Diets were balanced using MSP, calcium carbonate, salt and fine sand to maintain all other dietary ingredients at equal levels. A constant Ca:P ratio of 1.40 was maintained. Pigs were limit-fed individually at 3x197 kcal ME/kg BW0.60 based on the BW for each block. Final body weight tended (P = 0.085) to increase linearly with increasing P from MSP, but not from TLA (P = 0.271) or SLS (P = 0.367). Overall ADG linearly increased (P = 0.022) with increasing P from MSP (761, 814, and 839 g/d), tended to increase (P = 0.072) with P from TLA (761, 786, and 810 g/d), and was not impacted (P = 0.164) by P from SLS (761, 797, and 814 g/d). Kidney weight relative to BW linearly decreased (P = 0.041) with increasing MSP, but liver, heart, and spleen weights were not affected (P > 0.07). Serum P linearly increased (P = 0.007) with increasing MSP (8.76, 9.08, and 10.00 mg/dL), but not with TLA (P = 0.250; 8.76, 8.52, and 9.28 mg/dL) or SLS (P = 0.143; 8.76, 9.18, and 9.41 mg/dL). Serum Ca concentrations linearly decreased (P < 0.033) with increasing MSP, TLA, and SLS. Data suggest that the value of TLA and SLS as a P source is limited compared with MSP.