RESUMEN
Iberian pigs have low rates of muscle protein deposition compared with modern breeds. Differences in net portal appearance (NPA) of amino acids (AA) might partially explain that. NPA of AA was measured in six Iberian and six Landrace gilts (28 kg) fitted with catheters in portal and mesenteric (para-aminohippuric acid infusion) veins, and carotid artery. Blood samples from porta and artery were simultaneously taken at 0, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, and 6-h after feeding two isoenergetic diets (14-14.5 MJ metabolizable energy/kg dry matter) with different crude protein (145 (LCP) and 187 (HCP) g/kg dry matter) content. NPA of essential AA (EAA) and non-essential AA (NEAA) was lower (p < 0.05) in Iberian than Landrace pigs, and in LCP than HCP diet. Fractional absorption (NPA/AA intake) of EAA, NEAA, and total AA was, respectively, 36, 49, and 44% lower in LCP than HCP diet in Iberian pigs; and 8, 2, and 4% greater in Landrace pigs. Fractional absorption of EAA, NEAA, and total AA was 42, 68, and 60% lower in Iberian than Landrace pigs fed LPC diet; and 1, 36, and 26% when fed the HCP diet. NPA of AA may partially explain the low growth rate of Iberian pigs.
RESUMEN
In this study, we examined the effects of acute intravenous administration of l-arginine on circulating levels of metabolites in the portal-drained viscera (PDV) of 12 barrows surgically fitted with chronic catheters in the portal vein. At day 14 post-surgery, the pigs were fasted for 12 hr and then randomly allocated to one of three groups to receive administration of normal saline, l-alanine [103 mg/kg body weight (BW), isonitrogenous control] or l-arginine-HCl (61 mg/kg BW), via the portal vein. Blood samples were obtained from the carotid artery before and at 30-min intervals for 5 hr after the administration of saline or amino acid in order to determine metabolic profiles. The results showed that, compared with the saline treatment, arginine infusion increased plasma concentrations of insulin-like growth factor-I, arginine and cystine in the portal vein plasma, whereas plasma concentrations of threonine, serine, leucine and methionine were reduced. These findings indicate that increasing arginine concentrations in the portal vein alters the metabolic profile in swine, an established animal model for studying human nutrition and metabolism.
Asunto(s)
Arginina/farmacología , Porcinos/sangre , Animales , Arginina/administración & dosificación , Esquema de Medicación , Inyecciones Intravenosas , Masculino , Vena Porta , Porcinos/metabolismoRESUMEN
In Iberian pig outdoor production, pigs are fed equilibrated diets until the final fattening period when grazing pigs consume mainly acorns from oak trees. Acorns are rich in energy but poor in crude protein where lysine is the first limiting amino acid (AA). Net portal appearance (NPA) is very useful to ascertain AA available for liver and peripheral tissues. The aim of this study was to determine NPA of AA in Iberian gilts fed with acorns and to ascertain if there was an effect of acorn feeding over time. Two sampling periods were carried out (after one day and after one week of acorn feeding) with six gilts (34 kg average BW) set up with three catheters: in carotid artery and portal vein for blood sampling, and ileal vein for a marker infusion to measure portal plasma flow (PPF). Pigs were fed at 2.5 × ME for maintenance a standard diet in two meals, at 09:00 (0.25) and 15:00 h (the remaining 0.75). The day previous to first sampling, pig diet was replaced by 2.4 kg of acorn. A serial blood collection was done at -5 min, 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5 and 6 h after feeding 0.25 of total daily acorn ration. Following identical protocol, one week later the second sampling was done. NPA of sum of essential AA (EAA) was poor. Although increased NPA of histidine (P < 0.001), leucine, phenylalanine and valine (0.05 < P < 0.08) was found after one week of acorn consumption, the sum of EAA did not change. Furthermore, fractional absorption (NPA/AA intake) of EAA, non-essential AA (NEAA) and total AA was 97, 44 and 49% lower, respectively, at the beginning of eating acorn than a week later. Supplementation, with some of the EAA and NEAA to Iberian pigs during the grazing period would be beneficial to overcome the increased portal-drained viscera (PDV) utilization of AA observed in the present study.
RESUMEN
Most valuable cured products from Iberian pigs come from pure bred animals raised for a final grazing-fattening period where pigs eat mainly acorns, a low protein energy rich fruit. This is a nutritional challenge for animals fed equilibrated diets from weaning. The aim of the study was to determine net portal appearance (NPA) of metabolites in gilts fed acorns and evaluate adaptational changes after one week of feeding. Two sampling periods were carried out (after one day and after one week of acorn feeding) with six gilts (34 kg average BW) set up with three catheters: in carotid artery and portal vein for blood sampling, and ileal vein for para-aminohippuric acid (PAH) infusion to measure portal plasma flow (PPF). Pigs were fed at 2.5 × ME for maintenance a standard diet in two portions, at 09:00 (0.25) and 15:00 h (the remaining 0.75). On the day prior to the first sampling period, pigs were fed 2.4 kg of oak acorns. After feeding 0.25 of ration a 6 h serial blood collection was initiated. Following an identical protocol, a second sampling session was performed 1 week later. Adaptation to acorn consumption decreased NPA of ammonia (47%, P < 0.001). Although there was a transfer of urea from the gastrointestinal tract to the circulation in both sampling periods, no differences in NPA of urea was found (P > 0.05). NPA of glucose was not influenced by sampling period (P > 0.05), but NPA of lactate was greatly increased (231%, P < 0.001). There was a negative NPA of albumin although adaptation to acorn feeding did not alter it. Although NPA of triglycerides and cholesterol were unchanged, a subtle increase in arterial and portal cholesterol was noticed (9.6%, P < 0.01). Pigs fed a protein deficient diet for one week adapted decreasing NPA of ammonia for saving metabolic energy as less ammonia would become available for conversion to urea.
RESUMEN
In nutrition studies, para-aminohippuric acid (PAH) is a marker frequently used to measure blood flow in pigs, which is essential for estimating portal-drained viscera (PDV) flux of nutrients. The aim of this study was to evaluate the PAH analytical method by means of qualimetric statistical procedures to estimate the matrix effect and the accuracy and limits of quantitation of the method. Net PDV flux of nutrients was determined in five multi-catheterized pigs using water, plasma or commercial serum as standard matrix. A proportional systematic error due to matrix effect was found for plasma and serum. Mean recovery was 99.4%, and intra- and inter-day precision of the method was 2.4% and 3.8% relative standard deviation, respectively. The limit of quantification was 0.22 mg PAH/l. Use of water for the PAH standard curves underestimated portal blood flow compared with PAH standards prepared with plasma or commercial serum (706, 954 and 927 ml/min; P<0.05, respectively). Consequently, PDV O2 consumption, glucose and amino acids fluxes were underestimated by 33% (P<0.001). In conclusion, our results stress the importance of using plasma from pigs not infused with PAH or alternatively commercial pig serum to prepare PAH standards to determine blood flow in pigs to avoid underestimation of blood flow.
Asunto(s)
Estudios de Evaluación como Asunto , Porcinos/metabolismo , Ácido p-Aminohipúrico/análisis , Aminoácidos/metabolismo , Animales , Calibración , Glucosa/metabolismo , Indicadores y Reactivos/análisis , Hígado/metabolismo , Oxígeno/metabolismo , Consumo de Oxígeno , Vena Porta/metabolismo , Porcinos/sangre , Vísceras/metabolismoRESUMEN
Four Polwarth castrated male sheep (42 ± 4.4 kg live weight (LW) surgically implanted with chronic indwelling catheters into the mesenteric, portal and hepatic veins, housed in metabolism cages and offered Cynodon sp. hay at rates (g of dry matter (DM)/kg LW) of 7, 14, 21 or ad libitum, were used in a 4 × 4 Latin square experiment to evaluate the effect of the level of forage intake on blood flow and oxygen consumption by the portal-drained viscera (PDV), liver and total splanchnic tissues (ST). The portal blood flow and the oxygen consumption by PDV linearly increased at increased organic matter (OM) intake. No effect of level of OM intake was obtained for the hepatic artery blood flow and oxygen consumption by liver. As a consequence, the level of OM intake only tended to directly affect hepatic blood flow and oxygen consumption by total ST. Oxygen consumption was linearly and positively related to blood flow across PDV, liver and total ST. The heat production by PDV and total ST, as proportion of metabolizable energy (ME) intake, decreased curvilinearly at increased ME intake. In conclusion, the oxygen consumption by PDV, but not by liver, was directly related to the level of forage intake by sheep. Moreover, when ingested at levels below maintenance, most of ME was spent as heat produced by ST.
Asunto(s)
Alimentación Animal/análisis , Ingestión de Alimentos/fisiología , Consumo de Oxígeno/fisiología , Poaceae/química , Ovinos/fisiología , Circulación Esplácnica/fisiología , Fenómenos Fisiológicos Nutricionales de los Animales , Animales , Dieta/veterinaria , MasculinoRESUMEN
BACKGROUND: Betaine and conjugated linoleic acid (CLA) may alter growth and body composition in pigs, although their mode of action is not well understood. Portal-drained viscera (PDV) have a disproportionate influence with respect to their masses, and this may affect the productivity of more profitable tissues. The objective of this study was to determine if the use of betaine and/or CLA in the diet affects PDV heat production. RESULTS: Postprandial portal blood flow (PBF) was greater (19.0%, P = 0.004) for control compared with the other three diets. The lowest (P < 0.001) value for postprandial PDV O2 consumption corresponded to betaine + CLA followed by betaine and CLA diets (32.7, 25.4 and 17.7% respectively with respect to control diet). Postprandial PDV heat production was greater (26.4%, P < 0.001) for control with respect to the other three diets, with the minimum value corresponding to betaine + CLA (34.1% lower than control). CONCLUSION: Supplementation with betaine and/or CLA reduced the PBF, O2 consumption and therefore PDV heat production with respect to control diet. This effect was more pronounced when betaine and CLA were supplemented together, potentially increasing the energy availability for other body tissues. © 2016 Society of Chemical Industry.
Asunto(s)
Betaína/administración & dosificación , Dieta/veterinaria , Metabolismo Energético , Ácidos Linoleicos Conjugados/administración & dosificación , Flujo Sanguíneo Regional , Sus scrofa/metabolismo , Vísceras/irrigación sanguínea , Animales , Animales Endogámicos , Betaína/metabolismo , Composición Corporal , Regulación de la Temperatura Corporal , Ingestión de Energía , Masculino , Orquiectomía/veterinaria , Consumo de Oxígeno , Sistema Porta/fisiología , Periodo Posprandial , Distribución Aleatoria , España , Sus scrofa/crecimiento & desarrollo , Vísceras/crecimiento & desarrollo , Vísceras/metabolismo , Aumento de PesoRESUMEN
Supplemented protein or specific amino acids (AA) are proposed to help animals combat infection and inflammation. The current study investigates whole-body and splanchnic tissue metabolism in response to a lipopolysaccharide (LPS) challenge with or without a supplement of six AA (cysteine, glutamine, methionine, proline, serine and threonine). Eight sheep were surgically prepared with vascular catheters across the gut and liver. On two occasions, four sheep were infused through the jugular vein for 20 h with either saline or LPS from Escherichia coli (2 ng/kg body weight per min) in a random order, plus saline infused into the mesenteric vein; the other four sheep were treated with saline or LPS plus saline or six AA infused via the jugular vein into the mesenteric vein. Whole-body AA irreversible loss rate (ILR) and tissue protein metabolism were monitored by infusion of [ring-2H2]phenylalanine. LPS increased (P<0·001) ILR (+17 %), total plasma protein synthesis (+14 %) and lymphocyte protein synthesis (+386 %) but decreased albumin synthesis (-53 %, P=0·001), with no effect of AA infusion. Absorption of dietary AA was not reduced by LPS, except for glutamine. LPS increased the hepatic removal of leucine, lysine, glutamine and proline. Absolute hepatic extraction of supplemented AA increased, but, except for glutamine, this was less than the amount infused. This increased net appearance across the splanchnic bed restored arterial concentrations of five AA to, or above, values for the saline-infused period. Infusion of key AA does not appear to alter the acute period of endotoxaemic response, but it may have benefits for the chronic or recovery phases.
Asunto(s)
Aminoácidos/metabolismo , Arterias/metabolismo , Endotoxemia/metabolismo , Endotoxinas/efectos adversos , Inflamación/metabolismo , Biosíntesis de Proteínas , Circulación Esplácnica , Aminoácidos/farmacocinética , Aminoácidos/farmacología , Aminoácidos/uso terapéutico , Animales , Proteínas Sanguíneas/metabolismo , Suplementos Dietéticos , Endotoxemia/tratamiento farmacológico , Endotoxemia/microbiología , Endotoxemia/patología , Escherichia coli , Femenino , Inflamación/tratamiento farmacológico , Inflamación/etiología , Inflamación/microbiología , Infusiones Intravenosas , Lipopolisacáridos , Hígado/metabolismo , Linfocitos/metabolismo , Masculino , Biosíntesis de Proteínas/efectos de los fármacos , Proteínas/metabolismo , OvinosRESUMEN
BACKGROUND: In terms of whole-body metabolism, visceral tissues have a disproportionate influence with respect to their masses, and under certain circumstances their high metabolic rate may compromise nutrient availability to the tissues of productive/economic interest. The low energy efficiency of Iberian compared to modern breeds could be partly explained by the contribution of portal-drained viscera to heat production. The objective of this study was to determine the relative contribution of portal-drained viscera heat production (PDVHP) to total heat production (THP) in Iberian and Landrace gilts fed a diet with low protein content. RESULTS: Compared to Landrace, Iberian gilts (29 ± 0.9 kg body weight) had lower pre- and postprandial portal vein blood flow (654 vs. 965, and 746 vs. 1133 mL min(-1) , respectively; P < 0.01), postprandial PDVHP (3.09 vs. 3.88 kJ h(-1) kg(-0.75) ; P < 0.01) and PDVHP/THP ratio (0.08 vs. 0.13; P < 0.05), and greater THP (38.5 vs. 31.8 kJ h(-1) kg(-0.75) ; P < 0.05), when offered 0.25 of their daily ration in a 6 h sampling period. CONCLUSION: In spite of the low energetic efficiency and growth rate of Iberian compared to modern breeds, the contribution of PDV energy expenditure relative to THP was lower in Iberian compared to Landrace gilts in the present study.