Wheat serves as a major alternative to corn in layer diets. However, the assessment and predictive models for standardized ileal digestibility of amino acids ( SIDAA ) from wheat in pullets have not yet been fully established, limiting precision formulation. This study aimed to evaluate the physical properties, conventional nutritional components, amino acid profiles and SIDAA in 10 wheat samples from different sources when fed to pullets during brooding (d 28-31) and growing (d 92-95) periods, and to develop SIDAA prediction equations base on physical properties, chemical components of wheats. A total of 594 and 396 Jingfen No.8 pullets, during brooding and growing periods respectively, were randomly assigned to one of 11 dietary groups. The diets included a nitrogen-free diet for measuring the basal endogenous loss of amino acid, and 10 test diets containing 92.53% wheat as the sole source of amino acid. Moreover, all diets contained 0.5% of titanium dioxide as and indigestible indicator. The chemical components of the 10 wheat samples from different sources showed considerable variation. In particular, the coefficients of variation for ether extract ( EE ), crude fiber, neutral detergent fiber, calcium ( Ca ), and total phosphorus ( TP ) all exceeded 10%. The SID values of the 15 analyzed amino acids differed significantly among the wheat samples ( P 0.80 were identified for the growing period. In conclusion, this experiment demonstrates that the chemical properties of wheat can be used to establish accurate equations for predicting the SID of most amino acid in pullets, serving as a reliable tool for rapid and accurate evaluation of amino acid nutritional value of wheat in pullets during both the brooding and growing periods.
Liu et al. (Sun,) studied this question.