[Absence of effect of the incorporation of a milk phosphopeptide on the utilization of calcium and phosphorus in the young pig].

Casein phosphopeptides are known to influence calcium absorption. A 50-day study was performed in 6-week old pigs fed either a control diet or a 5% casein phosphopeptide-containing diet (PP group). Both diets provided similar amounts of Ca (0.8%), P (0.5%), proteins, energy and vitamins. PP diet provided near 1/2 of total Ca, 1/3 of total P and 1/5 of proteins in the form of casein phosphopeptide. Ca and P excretion, absorption and retention were evaluated during a 10-day balance study. Bones were collected at slaughter to determine density, bending moment and bone mineral content. Calcium absorption and bone parameters (urinary hydroxyproline included) were not influenced by the type of diet. P absorption, but not retention, was slightly higher in the control group. Urinary Ca was higher and urinary P lower in PP pigs than in controls. These changes might result from the different kinds of dietary phosphorus, inorganic versus phosphopeptide, rather than from the difference between dietary proteins.