Guoyao Wu

1. IntroductionBoth L-glutamate (Glu) and L-glutamine (Gln) are abundant amino acids (AAs) in plant, microbial, and animal proteins [1]. In the whole bodies of sheep and cattle, Glu and Gln are the third and eighth most abundant AAs, respectively. For comparison, the total content of these two AAs, along with other AAs, in feeds [e.g., Bermuda grass, distillers dried grains, and solubles (DDGS)], ...

IntroductionCreatine (essential for energy metabolism) and glutathione (GSH; an important non-enzymatic antioxidant) are major metabolites of glycine [the simplest amino acid (AA)] in animals (Fig.  1). Specifically, arginine:glycine amidinotransferase (AGAT) and guanidinoacetate N-methyltransferase (GAMT) convert glycine into creatine in the presence of arginine and methionine, whereas &gamm ...

4.1 IntroductionThe metabolism of most nutrients in domestic dogs and cats is similar to that in other mammals (Baker and Czarnecki-Maulden 1991). Thus, the qualitative dietary requirements of dogs and cats for most nutrients [e.g., amino acids (AAs) that are not formed de novo in animal cells] are similar to those for omnivores (e.g., humans and pigs). However, dogs and cats have a relatively sho ...

1. IntroductionThe small intestine is a highly differentiated and complex organ with many nutritional, physiological, and immunological functions [1–8]. First, the small intestine is responsible for the terminal digestion and absorption of dietary nutrients and is, therefore, essential to health, growth, development, reproduction, and sustaining life in organisms. Second, the neonatal small ...

IntroductionThe domestic dog (Canis familiaris) and the domestic cat (Felis catus) have been human companions for at least 12,000 and 9000years, respectively [1, 2]. These animals contribute to the mental health and well-being of children, adolescents, and adults, and have become increasingly popular in many countries and worldwide over the past decades (Table  1). For example, the numbers of ...