The objective of this study was to evaluate the effects of different sources of phosphorus on performance, organ weight and blood parameters of pigs. One hundred and twelve pigs with body weight 28.65±2.82kg were distributed into randomized blocks, in a 8 × 2 factorial scheme (eight sources of phosphorus × two sexes), with four repetitions for males and three for females, with two animals per pen. The pigs were fed diets containing: dicalcium phosphate (DCP); monodicalcium phosphate (MCP); triple superphosphate (TS); single superphosphate (SS), Catalão-rock phosphate (ROCK), mix of sources (MIX), phosphoric acid (PAc) or a diet without any supplemental source of phosphorus (CONT). At 60 and 90kg, all pigs were weighed and blood samples were collected to determine alkaline phosphatase activity (APA), calcium (Ca) and phosphorus (P) and one animal per pen was killed to weigh the liver and kidneys and evaluate carcass yield. The use of diet CONT reduced the weight gain and feed intake, worsened feed:gain ratio and increased the relative weight of the kidneys, APA and Ca, and decreased blood P. The sources DCP, MCP, TS and PAc reduced the APA and maintained the P and Ca in the blood constant. Phosphorus sources TS, SS, ROCK and MIX generate similar levels of APA in pigs from 30 to 90kg to the diet without inorganic source of phosphorus without affecting their performance.
alkaline phosphatase; blood phosphorus; fluorine; kidneys