Two experiments were conducted to evaluate the performance and calcium excretion of broilers fed the diets with different amino acids (AA) and calcium (Ca) levels in the initial phase. In each experiments, male broilers, Cobb or Avian Farms, were randomly assigned to six treatments in a three X two factorial arrangement, considering the factors AA (100, 125 and 150% NRC, 1994) and Ca (75 and 100% NRC, 1994), in three replications of 30 birds each. The studied AA were methionine, methionine + cystine, lysine and threonine. The performance of the birds was analyzed according weight gain, feed intake and feed conversion. The lower calcium level reduced calcium excretion and increasing amino acids levels reduced weight gain in Avian Farms strain. The Cobb strain was not affected by treatments.
amino acids; broilers; calcium; performance; strains
