Evaluation of barley as a source of protein for chicks. I. Variety and nitrogen application in relation to protein content and amino‐acid composition of the seed

Abstract Seventy‐six samples of barley embracing 14 varieties grown under various conditions of nitrogen fertilisation in different locations in the U.K. were examined for nitrogen content and 14 samples were analysed for their total content of amino acids other than tryptophan. Top dressing with nitrogenous fertilisers during growth resulted in the production of grain with a higher nitrogen content as well as an increased overall yield of nitrogen/hectare. The growth locality had a greater effect upon the nitrogen content of the harvested seed than did the application of nitrogen to the growing crop. Lysine content was inversely proportional to crude protein content for barleys containing between 8 and 11% crude protein and, in consequence, within this range the yield of lysine/ton of grain was of the same order.