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

Abstract: 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 BW^0.60 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 to MSP.