Determination of true digestive utilization of phosphorus and the endogenous phosphorus outputs associated with soybean meal for growing pigs.
The objectives of this study were to determine true P digestibility, the gastrointestinal endogenous P outputs associated with soybean meal (SBM), and the role of the large intestine in P digestion in growing pigs. Four Yorkshire barrows, with average initial and final BW of 40 and 58 kg, were fitted with a simple T-cannula at the distal ileum and fed four diets according to a 4 x 4 Latin square design. The diets were cornstarch-based and contained four levels of P (0.098, 0.196, 0.293, and 0.391% on a DM basis) from solvent-extracted conventional SBM. Chromic oxide (3.5 g/kg of diet, as-fed basis) was included as a digestibility marker. Each experimental period consisted of 8 d with a 4-d adaptation period and a 4-d collection of representative ileal digesta (2 d) and fecal (2 d) samples. True ileal and fecal P digestibility values and the ileal and fecal endogenous P outputs associated with SBM were determined by the regression analysis technique. There were no differences (P > 0.05) in true P digestibility values (ileal, 59.0 +/- 8.3 vs. fecal, 51.3 +/- 7.9%, n = 16) and endogenous P outputs (ileal, 0.59 +/- 0.18 vs. fecal, 0.45 +/- 0.21 g/kg of DMI, n = 16) between the ileal and the fecal levels. The endogenous fecal P loss accounted for 8.1 and 17.6% of the NRC (1998) recommended total and available P requirements in growing pigs, respectively. In conclusion, approximately 51% of the total P in conventional SBM is digested in growing pigs. The large intestine does not play an important role in the digestion of P associated with SBM in the growing pig. The fecal loss of the gastrointestinal endogenous P is an important route of P excretion in the growing pig.
Department of Animal and Poultry Science, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
A
A
Ajakaiye
M Z
MZ
Fan
T
T
Archbold
R R
RR
Hacker
C W
CW
Forsberg
J P
JP
Phillips
D000818:Animals; D017608:Chromium Compounds / Q000378:metabolism; D004063:Digestion; D004305:Dose-Response Relationship, Drug; D005243:Feces / Q000737:chemistry; D007082:Ileum / Q000378:metabolism*; D007408:Intestinal Absorption; D008297:Male; D009751:Nutritional Requirements; D009753:Nutritive Value; D010758:Phosphorus / Q000378:metabolism*; D011897:Random Allocation; D012044:Regression Analysis; D013025:Glycine max; D013552:Swine / Q000254:growth & development / Q000378:metabolism*
D017608:Chromium Compounds; D010758:Phosphorus; C023600:chromic oxide