Triennial Growth Symposium: Important roles for L-glutamine in swine nutrition and production
ABSTRACT L-Glutamine (Gln) has traditionally not been considered a nutrient needed in diets for livestock species or even mentioned in classic animal nutrition textbooks. This is due to previous technical difficulties in Gln analysis and the unsubstantiated assumption that animals can synthesize sufficient amounts of Gln to meet their needs. Consequently, the current (1998) version of NRC does not recommend dietary Gln requirements for swine. This lack of knowledge about Gln nutrition has contributed to suboptimal efficiency of global pig production. Because of recent advances in research, Gln is now known to be an abundant AA in physiological fluids and proteins and a key regulator of gene expression. Additionally, Gln can regulate cell signaling via the mammalian target of rapamycin pathway, adenosine monophosphate-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and nitric oxide. The exquisite integration of Gln-dependent regulatory networks has profound effects on cell proliferation, differentiation, migration, metabolism, homeostasis, survival, and function. As a result of translating basic research into practice, dietary supplementation with 1% Gln maintains gut health and prevents intestinal dysfunction in low-birth-weight or early-weaned piglets while increasing their growth performance and survival. In addition, supplementing 1% Gln to a corn- and soybean-meal-based diet between d 90 and 114 of gestation ameliorates fetal growth retardation in gilts and reduces preweaning mortality of piglets. Furthermore, dietary supplementation with 1% Gln enhances milk production by lactating sows. Thus, adequate amounts of dietary Gln, a major nutrient, are necessary to support the maximum growth, development, and production performance of swine.
- SourceAvailable from: François Blachier
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- "If hepatic release is reduced, as observed Fig. 2 Rates of amino acid accretion in fetal pigs. Data are compiled from Wu et al. (1999) during dexamethasone-induced parturition, glutamine plays a central role in fetal carbon and nitrogen metabolism and exhibits the highest fetal/maternal plasma ratio among all amino acids in pigs (Wu et al. 2011). Throughout most of the gestation, there is an interorgan exchange of glutamine and glutamate between the placenta and fetal liver. "
ABSTRACT: The present review focuses on the physiological functions of glutamate-glutamine exchange involving placental amino acid transport and umbilical amino acid uptake in mammals (particularly in sows), with special emphasis on the associated regulating mechanisms. Glutamate plus glutamine are among the most abundant and the most utilized amino acids in fetus during late gestation. During pregnancy, amino acids, notably as precursors of macromolecules including proteins and nucleotides are involved in fetal development and growth. Amino acid concentrations in fetus are generally higher than in the mother. Among amino acids, the transport and metabolism of glutamate and glutamine during fetal development exhibit characteristics that clearly emphasize the importance of the interaction between the placenta and the fetal liver. Glutamate is quite remarkable among amino acids, which originate from the placenta, and is cleared from fetal plasma. In addition, the flux of glutamate through the placenta from the fetal plasma is highly correlated with the umbilical glutamate delivery rate. Glutamine plays a central role in fetal carbon and nitrogen metabolism and exhibits one of the highest fetal/maternal plasma ratio among all amino acids in human and other mammals. Glutamate is taken up by placenta from the fetal circulation and then converted to glutamine before being released back into the fetal circulation. Works are required on the glutamate-glutamine metabolism during late pregnancy in physiological and pathophysiological situations since such works may help to improve fetal growth and development both in humans and other mammals. Indeed, glutamine supplementation appears to ameliorate fetal growth retardation in sows and reduces preweaning mortality of piglets.Amino Acids 11/2014; 47(1). DOI:10.1007/s00726-014-1861-5 · 3.65 Impact Factor
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- "Glutamate and Gln are major metabolic fuels for the mammalian small intestine (Rezaei et al. 2013a; Wu 1998) and represent the most abundant free and protein-bound AA in milk of all mammals (Davis et al. 1994a, b; Wu and Knabe 1994; DeSantiago et al. 1999; Ramirez et al. 2001), and these AA are considered to be essential during the first days of life of the suckling newborn (Rezaei et al. 2013b; Wu et al. 2011b). In sows and rats, mammary uptake of Glu and Gln is quantitatively the highest of all AA (Viña and Williamson 1981; Trottier et al. 1997). "
ABSTRACT: Amino acids (AA) are not only building blocks of protein but are also key regulators of metabolic pathways in animals. Understanding the fate of AA is crucial to optimize utilization of AA for milk protein synthesis and, therefore, to reduce inefficiencies of nutrient utilization during lactation. By understanding the functional role of AA metabolism in mammary tissue, we can uncover pathways and molecular targets to improve AA utilization by mothers and neonates during the lactation period. The major objective of this article is to highlight recent advances in mammary AA transport, metabolism and utilization. Such knowledge will aid in refining dietary requirements of AA for lactating mammals, including women, sows and cows.Amino Acids 09/2014; 46(11). DOI:10.1007/s00726-014-1818-8 · 3.65 Impact Factor
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- "The amount of glutamine in the basal maternal diet (2 kg/day) is inadequate for fetal growth and development in swine. Thus, supplementing glutamine to the swine diet during late gestation enhances fetal growth and litter birth weight (Wu et al. 2011). Glutamine and its metabolite, glutamate, also have a beneficial role in stimulating neonatal growth. "
ABSTRACT: Intrauterine growth restriction (IUGR) is one of the most common concerns in human obstetrics and domestic animal production. It is usually caused by placental insufficiency, which decreases fetal uptake of nutrients (especially amino acids) from the placenta. Amino acids are not only building blocks for protein but also key regulators of metabolic pathways in fetoplacental development. The enhanced demands of amino acids by the developing conceptus must be met via active transport systems across the placenta as normal pregnancy advances. Growing evidence indicates that IUGR is associated with a reduction in placental amino acid transport capacity and metabolic pathways within the embryonic/fetal development. The positive relationships between amino acid concentrations in circulating maternal blood and placental amino acid transport into fetus encourage designing new therapies to prevent or treat IUGR by enhancing amino acid availability in maternal diets or maternal circulation. Despite the positive effects of available dietary interventions, nutritional therapy for IUGR is still in its infancy. Based on understanding of the underlying mechanisms whereby amino acids promote fetal growth and of their dietary requirements by IUGR, supplementation with functional amino acids (e.g., arginine and glutamine) hold great promise for preventing fetal growth restriction and improving health and growth of IUGR offspring.Amino Acids 03/2014; 46. DOI:10.1007/s00726-014-1725-z · 3.65 Impact Factor