Monosodium glutamate as a source of glutamic acid enhances weaner pig performance

摘要

L-glutamine (GLN), and the important role it plays in pig nutrition, has recently been highlighted (Wu et ah, 2011). In routine diet formulations GLN is often overlooked but its abundance in physiological fluids and tissues and the important regulatory role it plays in functions as diverse as immune response, gene expression and nutrient metabolism suggests more attention is warranted. Certainly, Wu et ah (2011) found the role of GLN to be so significant that they recommended that creep, late gestation and lactating sow diets be supplemented with 10 g/kg GLN. An impediment to GLN use in commercial diet formulations is cost. However, GLN and the related amino acid, glutamic acid, form part of a large intra- and inter-cellular and inter-organ GLN-glutamate cycle (Curi et ah, 2005). Glutamic acid can substitute for GLN in pathways such as ATP production and the synthesis of amino acids like arginine and proline. It can also inhibit GLN degradation and thus has a sparing effect on the use of GLN as a metabolic fuel (Wu et ah, 2011). Monosodium glutamate (MSG) is a cost-effective, widely available feed ingredient comprising ~ 780 g/kg glutamic acid, and may be a viable precursor to GLN in commercial pig diet formulations. The hypothesis tested was that inclusion of MSG in weaner diets would improve performance post-weaning.