The tryptophan requirements of young laying pullets.

摘要: Two experiments were conducted with laying pullets between 32 and 47 weeks of age. In each trial 1728 White Leghorn cross-bred used. A series diets increasing protein content was offered. Protein quality identical in all tryptophan demonstrated to be the most limiting amino acid mixture The daily requirement individual pullet estimated, by indirect methods, 2.25 mg/g egg output plus 10.25 mg/kg body weight. Response curves for flocks are illustrated. Calculated optimum intakes various ratios costs input value tabulated. It is estimated that a flock mean weight 1.5 kg, producing 55 g mass/hen d consuming 110 food/hen d, dietary concentration 1.7 g/kg when marginal cost supplying 1 kg 20 times output.