Which of the following is NOT one of the amino acids commonly found in swine diets?

The amino acid that is not commonly found in swine diets is glutamic acid. While lysine, leucine, and methionine are essential amino acids that are critical for growth and development in swine, glutamic acid is considered a non-essential amino acid. This means that pigs can synthesize glutamic acid from other nitrogen sources in their diet and that it is not required to be supplemented in significant quantities.

Lysine is vital for protein synthesis and is often the first limiting amino acid in swine diets, making it a primary focus for many nutritionists. Methionine, another essential amino acid, plays an important role in metabolism and growth. Leucine is significant for muscle protein synthesis and overall growth as well. The inclusion of these amino acids helps ensure optimal health and productivity in swine, while glutamic acid does not hold the same level of necessity in dietary formulations for pigs.