The relevance of functional amino acids to support the health of growing pigs

On commercial farms, young growing pigs are frequently affected by health problems from multifactorial origins (e.g. environmental changes, biosecurity, management, and feed) that result in inflammation and activation of body defenses. Inflammation states alter animal metabolism in such a way that nutrients (particularly amino acids) are diverted from the use for growth towards the production of defense-related proteins and low-molecular-weight compounds (e.g., nitric oxide, H2S, and glutathione) for supporting the activity of rapidly dividing cells such as immune cells and enterocytes. Furthermore, amino acids may act specifically as signaling molecules to regulate metabolic pathways during inflammation. Thus, new knowledge on the specific role and metabolism of each amino acid is needed to refine nutritional recommendations for pigs of different phenotypes and genotypes, with the objective of maintaining animal health and performance under sub-optimal rearing conditions. This paper aims at summarizing recent advances in research on the functional roles of amino acids related to swine health. Specifically, the review highlights current knowledge on the impact of inflammation on the intake and metabolism of amino acids; their relevance for the physical gut mucosal barrier and antioxidant defense, as well as their roles in the syntheses of defense molecules and in the regulation of immune response. Practical implications for feeding strategies adapted to various health conditions of growing pigs are also discussed along with our general perspectives on related research

Glutamine and cystine-enriched diets modulate aquaporins gene expression in the small intestine of piglets

Research Areas: Science & Technology ; Other TopicsABSTRACT - The regulation of glycerol permeability in the gastrointestinal tract is crucial to control fat deposition, lipolysis and gluconeogenesis. Knowing that the amino acid glutamine is a physiological regulator of gluconeogenesis, whereas cystine promotes adiposity, herein we investigated the effects of dietary supplementation with glutamine and cystine on the serum biochemical parameters of piglets fed on amino acid-enriched diets, as well as on the transcriptional profile of membrane water and glycerol channels aquaporins (AQPs) in the ileum portion of the small intestine and its impact on intestinal permeability. Twenty male piglets with an initial body weight of 8.8 ± 0.89 kg were allocated to four dietary treatments (n = 5) and received, during a four week-period, a basal diet without supplementation (control) or supplemented with 8 kg/ton of glutamine (Gln), cystine (Cys) or the combination of the two amino acids in equal proportions (Gln + Cys). Most biochemical parameters were found improved in piglets fed Gln and Cys diet. mRNA levels of AQP3 were found predominant over the others. Both amino acids, individually or combined, were responsible for a consistent downregulation of AQP1, AQP7 and AQP10, without impacting on water permeability. Conversely, Cys enriched diet upregulated AQP3 enhancing basolateral membranes glycerol permeability and downregulating glycerol kinase (GK) of intestinal cells. Altogether, our data reveal that amino acids dietary supplementation can modulate intestinal AQPs expression and unveil AQP3 as a promising target for adipogenesis regulation.info:eu-repo/semantics/publishedVersio

Influence du croisement génétique sur le métabolisme postprandial du tryptophane chez le porc

National audienceTryptophan (Trp), an indispensable amino acid, is involved in numerous metabolic pathways. Previous data showed that Trp conversion into kynurenine and nicotinamide may differ among studies and such differences cannot be explained by different dietary niacin supply. We hypothesized that pig genotype influences Trp metabolism and thus the conversion of Trp into metabolites. The objective of this study was to compare plasma appearance of Trp and related metabolites in 12 Duroc and 12 Piétrain crossbred growing pigs after a meal test. Pigs were fitted with a catheter in the jugular vein to perform frequent blood samplings. Within each genotype, 6 pigs were fed a limiting or non‐limiting Trp diet (15 and 22% Trp:Lys DIS, respectively). After an overnight fasting, 350 g of the experimental diets was offered to each pig and plasma concentrations of Trp, kynurenine, nicotinamide and serotonine were measured for 6 hours. The activities of Trp degrading enzymes were measured in different tissues collected after pig slaughtering. Our data showed an increase in plasma concentrations of Trp and its metabolites after the meal and with the Trp dietary content. However, plasma concentrations of Trp metabolites and enzyme activities were not significantly different between Duroc and Piétrain crossbred

Influence du croisement génétique sur le métabolisme postprandial du tryptophane chez le porc

Tryptophan (Trp), an indispensable amino acid, is involved in numerous metabolic pathways. Previous data showed that Trp conversion into kynurenine and nicotinamide may differ among studies and such differences cannot be explained by different dietary niacin supply. We hypothesized that pig genotype influences Trp metabolism and thus the conversion of Trp into metabolites. The objective of this study was to compare plasma appearance of Trp and related metabolites in 12 Duroc and 12 Piétrain crossbred growing pigs after a meal test. Pigs were fitted with a catheter in the jugular vein to perform frequent blood samplings. Within each genotype, 6 pigs were fed a limiting or non‐limiting Trp diet (15 and 22% Trp:Lys DIS, respectively). After an overnight fasting, 350 g of the experimental diets was offered to each pig and plasma concentrations of Trp, kynurenine, nicotinamide and serotonine were measured for 6 hours. The activities of Trp degrading enzymes were measured in different tissues collected after pig slaughtering. Our data showed an increase in plasma concentrations of Trp and its metabolites after the meal and with the Trp dietary content. However, plasma concentrations of Trp metabolites and enzyme activities were not significantly different between Duroc and Piétrain crossbred

Performance of piglets in response to the standardized ileal digestible phenylalanine and tyrosine supply in low-protein diets

Reducing the CP level of the diet allows for a reduction in N excretion without limiting performance as long as the amino acid (AA) requirements are covered. The availability of crystalline AA has permitted for a considerable reduction in the CP level of diets, practically used in pig nutrition. The adoption of low CP diets and the extent to which the CP content can be reduced further depends on the knowledge of the minimum levels of indispensable AA that maximize growth. The standardized ileal digestible (SID) Phe : Lys and Tyr : Lys requirements and the possibility to substitute Tyr by Phe have never been studied in piglets. The objectives of this study were to estimate these requirements in 10 to 20 kg pig as well as to determine the extent to which Phe can be used to cover the Tyr requirement. In three dose–response studies, six pigs within each of 14 blocks were assigned to six low CP diets (14.5% CP) sub-limiting in Lys at 1.00% SID. In experiment 1, the SID Phe : Lys requirement estimate was assessed by supplementing a Phe-deficient diet with different levels of L-Phe to attain 33%, 39%, 46%, 52%, 58%, and 65% SID Phe : Lys. Because Phe can be used for Tyr synthesis, the diets provided a sufficient Tyr supply. A similar approach was used in experiment 2 with six levels of L-Tyr supplementation to attain 21%, 27%, 33%, 39%, 45% and 52% SID Tyr : Lys. Phenylalanine was supplied at a level sufficient to sustain maximum growth (estimated in experiment 1). The SID Phe : Lys and SID Tyr : Lys requirements for maximizing daily gain were 54% and 40% using a curvilinear-plateau model, respectively. A 10% deficiency in Phe and Tyr reduced daily gain by 3.0% and 0.7%, respectively. In experiment 3, the effect of the equimolar substitution of dietary SID Tyr by Phe to obtain 50%, 57%, and 64% SID Phe : (Phe +Tyr) was studied at two limiting levels of Phe +Tyr. From 57% to 64% SID Phe : (Phe +Tyr), performance was slightly reduced. In conclusion, it is recommended not to use a Phe +Tyr requirement in the ideal AA profile but rather use a SID Phe : Lys of 54% and a SID Tyr : Lys of 40% to support maximal growth

Benefits of low crude protein diets in broiler: beyond CO2, the importance of N & NH3

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Un excès de leucine aggrave l’effet d’une carence en valine chez le porcelet

National audienceThe branched‐chain amino acids (BCAA: valine (Val), leucine (Leu), isoleucine) are considered to be among the next‐limiting amino acids for growth in piglets. In earlier studies, we estimated the standardized ileal digestible (SID) Val:Lys requirement at 70%. Because the BCAA partially share a common route of catabolism, the supply of one BCAA may affect the availability of the other BCAA. Two experiments were conducted to determine the response of 6‐week‐old piglets to the Val supply in relation to the excess of Leu. In experiment 1, the interaction between Val and Leu was studied in a 2x2 factorial design (60 and 70% SID Val:Lys, and 111 and 166% SID Leu:Lys). Daily gain decreased and feed conversion ratio increased by 30% and 23% respectively in piglets receiving 60% SID Val:Lys compared with those receiving 70% SID Val:Lys and was lowest in piglets receiving the diet with a low Val and high Leu content. To further evaluate the interaction between Val and Leu, a dose‐response study was carried out in which the response to Val supply was studied in combination with a high Leu content (165% SID Leu:Lys). Using a curvilinear‐plateau model, the average SID Val:Lys requirement was 72%. However, a low Val supply (60% SID Val:Lys) reduced performance by 13 to 38%, which was much greater than what we observed in earlier studies. In conclusion, a large supply of Leu does not affect the Val requirement per se, but may aggravate the consequences of a Val deficiency