Lysine and arginine requirements of the domestic cat

Domestic kittens were used in four experiments to establish quantitative requirements for lysine and arginine. A purified L-amino acid diet (by calculation, 4,700 kcal metabolizable energy/kg diet) was employed throughout. Weight gain, gain:feed and nitrogen retention data of cats fed dietary lysine levels ranging from 0.48 to 1.92% suggested a requirement not exceeding 0.80%. The dietary arginine requirement for maximal gain was assayed at this level of lysine and found to be not greater than 0.83%. A dietary arginine level of 0.33% resulted in vomiting and extreme lethargy within 4 hours of ingestion.