Methionine and Protein Requirements of Lines of Chickens Established by Growth-Rate Selection on a Methionine Deficient Diet

IN RECENT years, studies of amino acid biochemistry have centered about the following areas: 1. the detection and elucidation of minor pathways of intermediary metabolism; 2. the characterization of mechanisms, both humoral and nervous, controlling the rates of metabolic interconversions; 3. the quantitative assessment of the in vivo contribution of the established pathways to metabolism in general and 4. the determination of the mode and mechanism of the individual enzymatic reactions. It is likely that progress in these areas could be greatly accelerated by the use of lines of chickens developed through selection for efficiency of utilization of specific amino acids. The possibility of doing this has been indicated by several recent reports. Griminger and Fisher (1962) have shown that the growth potential of chicks reared on lysine and arginine deficient diets is inherited. However, selection was not attempted, nor was evidence provided that the absolute requirements of the chicks…