In earlier attempts to explain amino acid imbalance and toxicity (Chapter 7), the effect on taste receptors has consistently been rejected as one of the mechanisms. This dismissal persisted even by authors demonstrating food intake reductions within 3-6 h of feeding an unbalanced diet to both laboratory animals and chicks. However, Forbes (2000) maintains that animals do display specific appetites for lysine, methionine and other nutrients. It is possible that selection might involve taste receptors. In this respect, the findings of Nelson et al. (2002) concerning an amino acid taste receptor might be relevant. They demonstrated the existence of specific receptors able to function as L-amino acid sensors with the capacity to respond to most of the 20 standard amino acids but not to their D-isomers or to other compounds. There is a need to re-evaluate current concepts of taste sensation in animals to underpin work on feed intake enhancers. Amino acids play an important role in the payability of foods for cats and dogs (Chapter 22).
Was this article helpful?