ABSTRACT:
The purpose of this study was to assess the levels of available phosphorus (AP) in the diet of growing pigs selected for lean deposition on the hematological, biochemical, and bone performance parameters. A total of 64 commercial hybrid pigs (32 castrated males and 32 females; mean initial weight: 23.31±2.4kg; age: 55-90 days) were used. Animals were distributed into a randomized block design with four treatments, eight replicates, and two animals (one male and one female) per experimental unit. The treatments consisted of a basal diet and another three diets, which were obtained by supplementing the basal diet with dicalcium phosphate replacing the inert phosphate, resulting in four diets with 0.100, 0.180, 0.260, and 0.340% of available phosphorus. The levels of available phosphorus quadratically influenced the daily weight gain, feed consumption, and feed conversion, which increased up to the estimated levels 0.331; 0.330, and 0.302% of available phosphorus. Levels of phosphorus showed no influence on the hematological parameters, which remained within the reference values. Levels of available phosphorus increased linearly the ash and phosphorus contents in the metacarpal bone and decreased linearly the alkaline phosphatase activity. Levels of available phosphorus (0.331 and 0.302%, corresponding to a daily intake of 5.73 and 5.18g d-1) provided respectively the best results for weight gain and feed conversion in pigs with high genetic potential, without change in hematological parameters.
Key words:
requirement; blood tests; mineral; genetic potential.
