Methionine
Methionine is an essential amino acid in chicken feed. As the first limiting amino acid for laying hens, its insufficiencies will make the other amino acids unusable regardless of their abundant amount. Methionine can be used as a nutrient fortifier for protein feed. When the body leverages other amino acids, it is limited by the amount of methionine. The lack of methionine in the feed will cause slow growth, growth stagnation, weight loss, and reduced feed digestion and utilization.The effect of methionine on the immunity of chickens is to increase the level of antibodies produced by chickens substantially, which can significantly increase the transformation of lymphocytes, antibody titers, and the number of immunoglobulins. Lack of methionine will reduce the overall antibody level of the flock, thereby inducing viruses.Methionine also affects the egg weight. An appropriate amount of methionine in the feed can maintain the egg weight and a nice egg shape.