If an animal did not consume lysine in its diet, then it would not be able to synthesize many necessary proteins.
Explanation:
Lysine is an essential amino acid which helps the tissues to grow.
Lysine is a limiting amino acid which acts as a substrate to generate animal body proteins, and the peptide and non-peptide molecules.
In animals like chicken, swine etc grown for their meat, lysine is supplemented in animal feeds to increase their muscle tissue growth and increased meat production.
Further dietary lysine deficiency in animals will lead to reduction in muscle mass, impairment of immunity and body defense against infections, affects synthesis of many animal proteins like milk proteins in bovine animals.