Availability of amino acids in wheat cultivars used in diets for weanling rats

Nitrogen (N) and amino acid availabilities of No. 1 Canada Western Red Spring milling wheat, Neepawa; No. 1 Utility wheats, Glenlea, Norquay and unlicensed Purple PFW606A were calculated by balance trials with rats. Lysine availability values were also determined by the growth response method using regression analysis (weight gains vs. lysine consumed). Results of balance trials indicated that the availability values for N and amino acids in the different wheat cultivars were similar. The availability values for lysine (80–85%) and tyrosine (82–87%) were lower than the values (90–97%) for the other amino acids and for N (92–95%). The growth response method suggested that the lysine availability values in wheat proteins varied from 80 to 89%. The availability value for the purple wheat was about 5 and 10% lower than the values of Norquay and Glenlea or Neepawa wheat, respectively.