Digestible Lysine and Sulfur Amino Acid Requirements of Young Male Broilers in the Starter Period

Digestible lysine and sulfur amino acid (SAA) requirements of Ross male broilers were determined during the starter period in two experiments. Broilers were fed a control corn-soy diet (3200 kcal MEn/kg and 23% CP) for 6 days and then randomly assigned to dietary treatments until 16 days of age. The basal diet containing 19% CP was prepared in order to be deficient in lysine for experiment 1 and SAA for experiment 2. Seven graded increment levels of L-lysine HCl or Dl-methionine were added in absences of starch in experiment 1 and 2, respectively. All diets contained 3200 kcal MEn/kg and all essential amino acids, except for the test amino acid, were 10% higher than the NRC (1991) recommendations. The digestible lysine requirements of broilers based on broken-line and exponential models were 1.04 and 1.01%, respectively. The digestible SAA requirements for the mentioned models were 0.846 and 0.841%, respectively.