title: True total-tract digestibility of phosphorus in corn and soybean meal for fifteen-kilogram pigs are additive in corn-soybean meal diet.
abstract: The objective of this study was to verify the additivity of true total-tract P digestibility (TPD) in corn and soybean meal (SBM) for 15-kg pigs. Fifty-four barrows with an average initial BW of 14.7±1.6 kg were used in a randomized complete block design with a 3×2 factorial arrangement of 6 diets. Three P sources included corn, SBM, and their mixture at a ratio of 2:1. Each P source was provided at low or high level. The diets were fed for a 5-d adjustment period followed by a total collection period of 7 d with ferric oxide as a marker to determine the initiation and termination of fecal collection. The results showed the high P level of each P source increased (P<0.001) P intake, fecal P output, and digested P compared with the low P level. The respective apparent total-tract digestibility of P were 35.66 and 40.57% for low and high P levels in corn, 35.72 and 38.04% for low and high P levels in SBM, and 41.85 and 38.53% for low and high P levels in the corn-soybean meal mixture without significant difference between P levels within P sources. Regressing daily digested P against daily P intake, the TPD was estimated at 40.53, 35.96, and 37.52% for corn, SBM, and their mixture, respectively. The expected TPD in corn and SBM mixture was calculated to be 37.92% based upon the P contribution coefficient calculated to be 0.428 for corn and 0.572 for SBM. The determined TPD (37.52%) in the mixture was not statistically different from the expected (37.92%). In conclusion, the TPD in corn and SBM are additive in corn-soybean meal diet for pigs.
authors.affiliation: Department of Animal Sciences, Purdue University, West Lafayette, IN 47907-2054, USA.
authors.forename: H
authors.initials: H
authors.lastname: Zhai
authors.forename: O
authors.initials: O
authors.lastname: Adeola
mesh_terms: D000821:Animal Feed / Q000032:analysis; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D004032:Diet / Q000662:veterinary*; D004063:Digestion / Q000502:physiology*; D005260:Female; D008297:Male; D016226:Phosphorus, Dietary / Q000378:metabolism*; D013025:Glycine max / Q000737:chemistry*; D013552:Swine / Q000502:physiology*; D003313:Zea mays / Q000737:chemistry*
chemical_list: D016226:Phosphorus, Dietary