Grain yields, chemical compositions, protein qualities, digestible energies and protein compositions were evaluated for high-lysine barley hybrids from crosses with mutant 7 in comparison with a high-lysine Hiproly-line and standard cultivars. Protein quality assessment was based on amino acid composition, true protein digestibility, biological value, net protein utilization and utilizable protein as determined in nitrogen balance experiments with rats. Nutritional quality was improved by the enhanced level of lysine and threonine since the biological value of the protein was significantly higher in the mutant 7-hybrids compared with normal barley. Despite the highest yield of total as wen as digestible energy per ha being obtained for a standard cultivar, the ratio between utilizable protein and digestible energy was more favorable for some of the high-lysine samples. Thus high-lysine barley, although lower-yielding than standard cultivars, may have advantages over the standard cultivars in animal diets.

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