Standardized total tract digestibility of phosphorus in blood products fed to weanling pigs

Objective: an experiment was conducted to measure the apparent (ATTD) and the standardized (STTD) total tract digestibility of P in spray dried plasma protein (SDPP), and in two sources of dried blood meal fed to weanling pigs. Methods: four diets were formulated. Three diets contained each of the three blood products. The only source of P in these diets was the blood products that were used. Each of three diets contained 60 - 60.4% cornstarch, 15% sucrose, 3% soybean oil, 1.3 or 0.9% limestone, 0.4% salt, and 0.3% vitamin and mineral premix in addition to 20% of each of the test ingredients (SDPP, porcine blood meal, or avian blood meal). The fourth diet was a P-free diet that was used to measure the basal endogenous phosphorus losses from the pigs that were fed this diet. Twenty four weanling pigs (initial BW: 18.8 ± 3.2 kg) were randomly allotted to the four dietary treatments with six pigs per treatment. Pigs had 5 days of adaptation to diets followed by 5 days of total collection of feces. Results: the ATTD of P was greater (p<0.01) for pigs that were fed SDPP (91.31%) than for pigs that were fed either porcine blood meal (76.46%) or avian blood meal (57.67%), and pigs that were fed porcine blood meal also had greater (p< 0.01) ATTD of P than pigs that were fed avian blood meal. There were no differences in the STTD of P between pigs that were fed porcine blood meal (89.74%) or avian blood meal (86.11%), but the STTD of P in these two ingredients was less (p < 0.05) than the STTD of P in SDPP (102.79%). Conclusions: the present experiment demonstrated that blood products are excellent sources of organic P. Spray dried plasma protein has a greater STTD of P than porcine or avian blood meal.