Effect of Supplemental dl-Methionine and Varying Protein Levels on Growth and Feed Requirements of Broiler Chickens ,

THE need for supplemental methionine in broiler rations has become more critical since soybean meal has been used to replace all or part of the animal protein supplements formerly used. The work of Bird and Mattingly (1945) Clandinin et al. (1946), Gerry et al. (1948), and Milligan et al. (1951) has shown that rations containing corn and soybean meal as the sole source of protein are improved with methionine supplementation. Results obtained by workers at the Dow Chemical Company (1951) have shown that the addition of dl-methionine to chick rations improved feed efficiency and had a variable effect on growth. Bird and Mattingly (1945) also demonstrated that the growth response obtained from the addition of 0.2% dl-methionine was slightly in excess of that obtained by the addition of 4% fish meal. The data obtained by Machlin et al. (1952) reveals that both vitamin B12 and methionine are necessary for maximum …