This study aimed to evaluate four sources of phosphorus for cattle grazing African Bermudagrass (Cynodon nlemfuesis Vanderyst) pasture and to compare them considering weight performance and physiological parameters. It was used a complete random experimental design, with 32 crossbred steers (Bos indicus x Bos Taurus) at average initial weight of 347 kg randomly distributed in four groups, each one receiving mineral supplement formulated with dicalcium phosphate, supertriple phosphate, monoammonium phosphate or Araxá rock phosphate, as sources of phosphorus. Weight gain per hectare differed among evaluation dates and it was significantly reduced in the last period, but it did not differ among sources of phosphorus. Average daily gain did not differ among sources of phosphorus and it was 0.67; 0.65; 0.63 and 0.56 kg/day, respectively for dicalcium phosphate, supertriple phosphate, monoammonium phosphate and Araxá rock phosphate. Concentrations of osteocalcin were kept in low levels (47.67 ng/mL) and they were similar among sources of phosphorus. Sources of phosphorus were efficient in keeping appropriate levels of phosphorus in serum, with an average of 7.03 mg/100 mL.
minerals; osteocalcin; ruminants; supplementation at pasture
