The evaluation of inorganic sulfur and sweet sorghum residues in poultry feed formulation

Abstract

New ingredients for poultry feed formulation were evaluated. The first study was undertaken to determine the performance of laying hens when fed inorganic sulfate, and to determine a possible sparing effect of inorganic sulfate on the methionine requirement. In this experiment a 16.5% protein diet, containing 0.77% lysine and 0.53% methionine plus cystine, and a 14.0% protein basal diet formulated to contain 0.77% lysine and 0.47% sulfur amino acids were used. Potassium sulfate (0.25%), methionine (0.05, 0.075 and 0.10%) and methionine and potassium sulfate combinations (0.025 + 0.125, 0.0375 + 0.1875 and 0.05 + 0.25) were added to the basal diet in order to observe the amino acid and protein sparing effects of inorganic sulfate. The nine dietary treatments were fed for twelve 28-day periods to pullets caged individually. Egg production and feed efficiency were approximately equal for all the dietary treatments, with the exception of dietary treatment 8 (basal + 0.05% methionine + 0.25% potassium sulfate) which significantly depressed egg production. The higher levels of methionine resulted in an increase in body weight to a greater extent than did sulfate. Egg size had a tendency to be depressed by potassium sulfate; however, methionine alone, or methionine and potassium sulfate combination at the higher levels tended to improve egg size. Feed, protein, and energy intakes were not affected by the different dietary treatments. ...