Synopsis
The amino acid requirements for the growing chick determined by Hewitt and Lewis (1972a) were tested at different protein levels. Satisfactory growth was obtained with 22 to 24% protein in the diet dry matter. Nitrogen balance data indicated that a good balance between amino acids, with no deficiencies, had been achieved.
The results of Hewitt and Lewis (1972a) were evaluated in conjunction with other published reports and a new set of requirement values derived. These were tested in a second experiment at different protein and energy levels. Excellent growth was recorded to 3 weeks of age when the diet satisfied these values and contained 0.9% lysine and 21% protein with a metabolisable energy value of 3.25 kcal/g.
Notes
Present address: National Institute for Research in Dairying, Shinfield, Reading RG2 9AT, England.