Influence of dietary fiber concentrations on the basal endogenous loss of phosphorus in growing pigs

Abstract Text: An experiment was conducted to determine basal endogenous losses (BEL) of phosphorus (P) in growing pigs fed P-free diets with various cellulose concentrations. Twelve barrows with an initial mean BW of 49.6 kg (SD = 3.2) were individually housed in metabolism crates that were equipped with a feeder and a nipple drinker. Pigs were allotted to 4 experimental diets according to a cross-over design. Experimental diets, based mainly on corn starch, sucrose, and gelatin, were formulated to contain 0, 4, 8, or 12% of cellulose. Each period consisted of a 5-d adaptation and a 5-d collection period. The marker-to-marker method was used for fecal collection. The feed intake and P intake were linearly and quadratically increased (P < 0.05) with increasing cellulose concentration in the diet. There were linear and quadratic increases (P < 0.05) in the feces output and feces output per feed intake with increasing cellulose concentration in the diet. However, the P content in the feces was decreased (P < 0.001) with increasing dietary cellulose concentration. The apparent total tract digestibility of DM and ash were linearly and quadratically decreased (P < 0.05) with increasing cellulose concentration in the diet. However, the BEL of P as mg per kg of DMI (ranged from 157 to 207 mg/kg of DMI) and total P output were not affected by the dietary cellulose concentrations. In conclusion, the dietary cellulose affects the digestibility of DM and ash, but the cellulose up to 12% does not affect the endogenous loss of P.

Keywords: cellulose, metabolic fecal phosphorus, swine