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Isabelle Ortigues Marty - One of the best experts on this subject based on the ideXlab platform.

  • Diet-animal fractionation of nitrogen stable isotopes reflects the efficiency of nitrogen assimilation in ruminants
    British Journal of Nutrition, 2015
    Co-Authors: Gonzalo Cantalapiedra Hijar, Isabelle Ortigues Marty, Bernard Sepchat, Jacques Agabriel, Jean-françois Huneau, Hélène Fouillet
    Abstract:

    The natural abundance of 15N in animal proteins (δ15Nanimal) is greater than that in the diet consumed by the animals (δ15Ndiet), with a discrimination factor (Δ15N = δ15Nanimal- δ15Ndiet) that is known to vary according to nutritional conditions. The objectives of the present study were to test the hypothesis that Δ15N variations depend on the efficiency of nitrogen utilisation (ENU) in growing beef cattle, and to identify some of the physiological mechanisms responsible for this N isotopic fractionation in ruminants. Thus, we performed the regression of the Δ15N of plasma proteins obtained from thirty-five finishing beef cattle fed standard and non-conventional diets against different feed efficiency indices, including ENU. We also performed the regression of the Δ15N of different ruminant N pools (plasma and milk proteins, urine and faeces) against different Splanchnic N fluxes obtained from multi-catheterised lactating dairy cows. The Δ15N of plasma proteins was negatively correlated with feed efficiency indices in beef cattle, especially ENU (body protein gain/N intake) and efficiency of metabolisable protein (MP) utilisation (body protein gain/MP intake). Although Δ15N obtained from different N pools in dairy cows were all negatively correlated with ENU, the highest correlation was found when Δ15N was calculated from plasma proteins. Δ15N showed no correlation with urea-N recycling or rumen NH3 absorption, but exhibited a strong correlation with liver urea synthesis and Splanchnic amino acid metabolism, which points to a dominant role of Splanchnic Tissues in the present N isotopic fractionation study.

  • Dietary nitrogen-to-energy ratio alters amino acid partition in the whole body and among the Splanchnic Tissues of growing rams
    Journal of Animal Science, 2010
    Co-Authors: Isabelle Savary-auzeloux, Guillaume Kraft, Brian J. Bequette, Isabelle Papet, Didier Remond, Isabelle Ortigues Marty
    Abstract:

    The aim of this study was to determine whether subtle changes in the energy-to-N ratio of medium-concentrate diets alters hepatic export protein synthesis and the partition of protein metabolism in the whole body of growing rams. Rams (n = 6; 41.5 ± 2.6 kg of BW) were fitted with catheters for measurement of Leu and Phe tracer kinetics across the portal drainedviscera (PDV) and liver. Rams were assigned to receive 3 dietary treatments according to a duplicated Latin square design. Animals received forage-concentratebased diets that were balanced for ME and available N (CON), 20% imbalanced (reduced) in available N (LN), or 20% imbalanced in ME (LE). After 15 d on each experimental diet, [ring-2H5]Phe (4.3 μmol·kg−1·h−1) and [1-13C]Leu (8.6 μmol·kg−1·h−1) were continuously infused into the vena cava for 10 h and, over the last 7 h of infusion, matched sets of blood samples were taken. Daily BW gain was less (P < 0.05) for the LE (0.191 kg·d−1) diet compared with CON (0.265 kg/d) and LN (258 kg·d−1) diets. Compared with CON, whole body irreversible loss rate (ILR) of Leu and Phe was less (10 to 16%, P < 0.02) for LN and LE diets, which for Leu reflected its decreased (20 to 24%, P < 0.05) net PDV absorption. The decreased whole body ILR is due to a decreased PDV ILR in both diets with a relative contribution of the PDV to the whole body ILR decreased (P < 0.05) in the LN (27%) diet compared with the CON (36%) and LE (33%) diets. This decreased PDV ILR was associated with a decreased net Leu PDV uptake in LN and LE diets (−25 and –20%, respectively; P < 0.05). Conversely, the decreased whole body Phe ILR is explained by a decreased hepatic ILR (and contribution to the whole body ILR) and was associated with a decreased net hepatic uptake of Phe in LN (−25%) and LE (−20%) diets compared with CON (P = 0.03). The fractional and absolute synthesis rates of total proteins and albumin were decreased by 10% in LE animals (P < 0.05), whereas they were not affected by the LN diet. These results suggest a specific decreased utilization of Leu at the PDV due to a specific sparing mechanism in the LN diet. Conversely, a decreased Phe utilization occurred in the liver in both diets (due to a decreased export protein synthesis and a probable decreased oxidation in LE diet, whereas only oxidation is reduced in LN diet).

  • Ryegrass-based diet and barley supplementation : partition of nitrogenous nutrients among Splanchnic Tissues and hind limb in finishing lambs
    Journal of Animal Science, 2003
    Co-Authors: Isabelle Savary-auzeloux, Nathalie Le Floc'h, Linda Majdoub, Isabelle Ortigues Marty
    Abstract:

    Splanchnic metabolism of nitrogenous nutrients and their uptake by the hind limb were studied in finishing lambs receiving ryegrass harvested at grazing stage with or without barley supplementation. Six multicatheterized lambs (40.2 +/- 1.5 kg) were fed with frozen ryegrass (RG) at 690 kJ of ME intake (MEI)(.)d(-1.)BW(-0.75) and 20.8 g of N intake (NI)/d successively without and with barley supplementation (RG + B), according to a crossover design. Barley supplementation represented 21% of DM intake and increased the MEI and the NI by 32 and 24% respectively, (P < 0.01). In the ruminal fluid, barley increased acetate and butyrate concentrations by 21.2 and 49.6%, respectively (P < 0.04), without any effect on the ammonia concentration. Consequently, the net portal appearance (NPA) of ammonia was not modified, but the NPA of total amino acids (TAA; +38%) and nonessential amino acids (NEAA; +45%) was increased (P < 0.05) by barley supplementation. Taken individually, the NPA of the essential amino acids (EAA) was increased for isoleucine (+32%; P < 0.05), threonine (+151%; P < 0.03), and lysine (+26%; P < 0.06), with no effect for the other EAA. In contrast to what was observed at the PDV level, no significant alteration in the net hepatic amino acid flux was observed for TAA, EAA, NEAA, branched-chain amino acids (BCAA)., urea, and, ammonia after barley supplementation, showing a relatively minor role of the liver in the regulation of the supply of amino acids to the peripheral Tissues. However, taken individually, the net hepatic uptake of some NEAA involved in gluconeogenesis and/or ureagenesis was altered with barley supplementation: the alanine uptake was increased by 44% (P < 0.05), aspartate + asparagine (asx) uptake was decreased by 18% (P < 0.01), and glutamate + glutamine (glx) release tended (P < 0.10) to be increased by 208%. With barley supplementation, NI increased by 5 g of N/d, and net Splanchnic release increased by 4.63 g of N/d. Consequently, the additional dietary N supply (together with energy supply) was nearly exclusively available to peripheral Tissues as AA-N (N as amino acids), but no strong effect of this additional supply of AA to the hind limb could be demonstrated in terms of net AA hind limb fluxes. Consequently, barley supplementation of a ryegrass-based diet increased the net AA release by the Splanchnic Tissues, with little effect on the AA net uptake by the peripheral Tissues.

  • Ryegrass-based diet and barley supplementation : Partition of energy-yielding nutrients among Splanchnic Tissues and hind limbs in finishing lambs
    Journal of Animal Science, 2003
    Co-Authors: Linda Majdoub, M. Vermorel, Isabelle Ortigues Marty
    Abstract:

    Splanchnic metabolism of energy-yielding nutrients and their uptake by the hind limb were studied in finishing lambs receiving ryegrass harvested at grazing stage (ear at 10 cm) with or without barley supplementation. Six ruminally cannulated and multi-catherized lambs (40.2 +/- 1.5 kg) were fed with frozen ryegrass (RG) at 690 kJ of metabolizable energy intake (MEI).d(-1).BW-0.75 successively with and without barley supplementation (RG + B), according to a triplicated Latin square design. Barley supplementation represented 21% of DM intake and increased the MEI by 32% (P < 0.002). In ruminal fluid, barley supplementation increased the acetate and butyrate concentrations by 21.2 and 49.6%, respectively (P < 0.04), without modifying those of propionate. Thus, molar proportions of acetate and butyrate were not modified, and those of propionate tended (P < 0.06) to decrease from 26 to 23%. As a result, the net portal appearance of propionate was not modified. Net portal appearance of butyrate and beta-hydroxybutyrate increased (P < 0.03), and that of acetate was not modified. Consequently, hepatic up-take of butyrate increased and probably spared acetate from hepatic metabolism. The hepatic fractional extraction of propionate decreased (P < 0.03), whereas the net flux of lactate switched from a net release to a net uptake, suggesting an alteration in the contribution of gluconeogenic substrates to glucose synthesis without modification in net hepatic glucose release. As a consequence, barley supplementation increased net Splanchnic release of acetate (P < 0.02), propionate (P < 0.001), and beta-hydroxybutyrate (P < 0.01) by 60, 157, and 78%, respectively. In addition, the net Splanchnic release of insulin increased (P < 0.03) because of a decrease (P < 0.02) in its hepatic extraction. Despite those changes, the net uptake of nutrients by the hind limb was not modified and even decreased in the case of glucose (P < 0.02), suggesting a stimulation of lipogenesis in adipose Tissues. Results from the present study suggested that supplementation of a ryegrass-based diet would likely have little effect on the orientation of muscle energy metabolism and on meat quality because the net uptake of nutrients by the hind limb was unchanged.

  • Energy expenditure of Splanchnic Tissues and hindlimbs in growing lambs fed frozen rye-grass: effects of barley supplementation and changes between 2.5 and 7 months of age
    Animal Research, 2003
    Co-Authors: Jean Vernet, Linda Majdoub, Isabelle Ortigues Marty
    Abstract:

    In order to study the effects of barley supplementation (Exp. 1), six lambs of 40 kg of body weight were fed on either rye-grass or rye-grass supplementedwith barley according to a triplicate Latin Square design at an estimated level of 1.5 and 2.0 fold the maintenance energy requirements. In order to study the effects of age (Exp. 2), 3, 6 and 5 lambs aged 2.5, 4 and 7 months old respectively were used. They were fed with rye-grass only at estimated levels of 1.8, 1.7 and 1.5 fold themaintenance energy requirements. All animals were equippedwith chronic blood catheters in the mesenteric artery, portal, hepatic and external iliac veins and with ultrasonic blood flow probes around the portal vein and the external iliac artery. In Experiment 1, portal blood flows increased by 11.5% with supplementation ($P < 0.05$) while iliac blood flow tended to increase by 15% (NS). Consequently, O2 consumption increased by 20% ($P < 0.03$), 35% ($P < 0.08$) and 19% (NS) in the portal drained viscera, liver and hindlimb, respectively, with barley supplementation. In Experiment 2, portal blood flow, expressed on a metabolic body weight basis, decreased by 17% from 2.5 to 4 months of age and did not change from 4 to 7 months ($P < 0.004$). Iliac blood flow did not increase significantly between 2.5 and 7 months of age due to large inter-individual variability. No significant effect of age was noted on portal drained viscera and liver energy expenditure expressed on a metabolic body weight basis, while the hindlimb energy expenditure tended to increase (NS). Itwas concluded that in supplementing ryegrass with barley, the increment in Splanchnic and carcass energy expenditure accounted for 30 and 26% of the increment of ME intake in finishing lambs and experimental results on organ and tissue energy expenditure obtained in ruminant lambs below 7 months of age may be applied to growing and finishing lambs.

A. L. Goetsch - One of the best experts on this subject based on the ideXlab platform.

  • net flux of nutrients across Splanchnic Tissues in wethers consuming bermudagrass or ryegrass wheat hay supplemented with rumen undegradable protein
    Small Ruminant Research, 1997
    Co-Authors: A. L. Goetsch, K.k. Park, J.e. Rossi, Z.s. Wang, D.l. Galloway, A R Paul, B. Kouakou
    Abstract:

    Crossbred wethers (14, 37 ± 1.5 kg BW and 10 months old) were used in a 21-day experiment (2 × 2 factorial) to determine effects of dietary grass source (tropical vs temperate) on response to rumen undegradable protein supplementation in oxygen consumption by, and net flux of N fractions across, the portal-drained viscera and liver. Bermudagrass (B; 73.1% NDF and 6.2% CP) or ryegrass-wheat (RW; 65.9% NDF and 8.9% CP) hay was supplemented with 53 g day−1 (DM) of soybean meal (S) or 53 g day−1 (DM) of soybean meal plus 70 g day−1 (DM) of a mixture of feedstuffs high in rumen undegradable protein (SR; 46.6% com gluten, 26.7% feather and 26.7% blood meals). Digestible energy intake (9.1, 10.0, 11.3 and 12.1 MJ day−1) was greater (P < 0.01) for RW than for B, and N intake was 12.5, 21.5, 16.5 and 25.3 g day−1 (SE 1.08) for B-S, B-SR, RW-S and RW-SR, respectively. Splanchnic energy use as a percentage of DE intake was less (P = 0.03) for RW vs B (21.4 vs 27.8%). Supplementation with Sr increased (P = 0.04) alpha-amino N release by the portal-drained viscera (6.6, 22.0, 9.8 and 20.6 mmol h−1) and hepatic uptake (10.9, 25.6, 11.2 and 14.3 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively; SE 2.29). Supplementation with Sr increased (P < 0.01) hepatic urea N release (26.7, 48.4, 29.0 and 41.8 mmol h−1) and ammonia N uptake (17.3, 29.7, 23.3 and 26.6 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively) more (interaction; P = 0.09 and 0.08, respectively) with B than with RW. In conclusion, these results indicate that DE intake and Splanchnic energy consumption for tropical and temperate grasses may influence metabolic fate of rumen undegradable protein N and, thus, impact potential performance benefits of supplementation. Also, unless forage intake is changed, any improvements in animal performance with rumen undegradable protein supplementation would be through increased N absorption without change in energy available to peripheral Tissues, regardless of grass source.

  • Net flux of nutrients across Splanchnic Tissues in wethers consuming grass hay with or without corn and alfalfa
    Animal Feed Science and Technology, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, J.e. Rossi, Z.s. Wang, D.l. Galloway, B. Kouakou
    Abstract:

    Fourteen crossbred sheep (33 kg body weight, SE = 1; 9 months of age) were used in a 21 day experiment (2 × 2 factorial) to determine if dietary substitution of grain (ground corn; C) for ryegrass-wheat hay (72% neutral detergent fiber and 9% crude protein) alters effects of legume (alfalfa hay: 60% neutral detergent fiber and 15% crude protein; A) substitution on Splanchnic tissue net flux of oxygen, alpha-amino nitrogen, urea and ammonia with ad-libitum consumption. Diets were approximately 100, 75, 75 and 50% grass, 0, 25, 0 and 25% C, and 0, 0, 25 and 25% A for control, C, A and CA treatments, respectively. Dietary inclusion of corn did not affect net fluxes or change effects of alfalfa. Alfalfa substitution did not alter dry matter intake, organic matter digestibility or oxygen consumption by the portal-drained viscera, liver or Splanchnic bed. However, alfalfa increased digestible nitrogen intake (P < 0.01; 6.0, 5.9, 9.8 and 10.3 g per day), hepatic release of urea nitrogen (P = 0.04; 30.6, 22.5, 38.6 and 41.4 mM h−1) and hepatic uptake of ammonia nitrogen (P = 0.04; 12.1, 10.7, 19.3 and 17.6 mM h−1 for control, C, A and CA, respectively) and decreased energy expenditure as a percentage of digestible energy intake by the portal-drained viscera (P = 0.02; 10.8 versus 13.1%) and Splanchnic bed (P = 0.08; 20.8 versus 23.3%). In conclusion, effects of substituting alfalfa for 25% of dietary grass, which was moderate to high in digestibility and moderate in nitrogen concentration, were not influenced by substitution of corn for grass.

  • Temporal net flux pattern of nutrients across Splanchnic Tissues in wethers consuming different forages
    Small Ruminant Research, 1997
    Co-Authors: K.k. Park, A. L. Goetsch, Zelpha B. Johnson, J.e. Rossi
    Abstract:

    Abstract Wethers consumed alfalfa, ryegrass-wheat or bermudagrass hay three times daily (8 h feeding interval). In Experiment 1 (ad libitum intake), DE intake was 2.96, 3.29 and 2.40 Mcal day−1 (SE 0.316), and digestible N intake was 17.7, 10.2 and 5.5 g day−1 (SE 0.99) for alfalfa, ryegrass-wheat and bermudagrass, respectively. Splanchnic oxygen consumption over an 8 h period was affected (P = 0.05) by a treatment by time post-feeding interaction because of a similar interaction (P = 0.08) in hepatic oxygen consumption. Alpha-amino N release by the portal-drained viscera was greater for alfalfa versus grasses and differed (P 0.10) with time post-feeding, and portal-drained viscera ammonia N release exhibited (P = 0.07) a treatment by time interaction. In conclusion, alfalfa consumed ad libitum resulted in a different temporal pattern of Splanchnic bed oxygen consumption than ryegrass-wheat or bermudagrass, but it did not appear that high oxygen consumption early after feeding alfalfa impacted subsequent oxygen use. Samples should be taken throughout an 8 h feeding interval, particularly early after feeding, to assess average net flux of nutrients across Splanchnic Tissues over the interval with ad libitum consumption or with a moderately restricted level of feed intake.

  • Oxygen consumption by Splanchnic Tissues in wethers consuming ad libitum different proportions of bermudagrass and ryegrass-wheat.
    Archiv fur Tierernahrung, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, Z.s. Wang, D.l. Galloway, B. Kouakou, J.e. Rossi
    Abstract:

    Crossbred wethers (n = 18, 7.5 month of age and 31 +/- 0.8 kg) were used in a 23-day experiment to determine effects of ad libitum consumption of diets differing in proportions of coarsely chopped bermudagrass and ryegrass-wheat hay (0, 33, 67 and 100%) on oxygen consumption by Splanchnic Tissues. Bermudagrass and ryegrass-wheat were 9 and 13% CP and 78 and 71% NDF, respectively. Intake of dry matter (1.03, 0.92, 0.92 and 0.76 kg/d) and digestible energy (13.5, 10.7, 10.6 and 8.2 MJ/d for 0, 33, 67 and 100% bermudagrass, respectively) changed linearly and cubically (P < 0.05) as bermudagrass level increased. Consumption of oxygen by the portal-drained viscera tended to decrease linearly (P = 0.14) with increasing bermudagrass (182, 154, 156 and 137 mM/h), and hepatic oxygen consumption decreased linearly (P < 0.05) and changed cubically (P = 0.07; 150, 113, 116 and 103 mM/h for 0, 33, 67 and 100% bermudagrass, respectively). Splanchnic tissue energy consumption expressed as a percentage of digestible energy intake increased linearly (P = 0.08) with increasing bermudagrass (24.0, 27.6, 28.6 and 33.2% for 0, 33, 67 and 100% bermudagrass, respectively). In conclusion, the level rather than presence alone of different grass sources consumed ad libitum affected energy use by the Splanchnic bed, and as a percentage of digestible energy intake Splanchnic bed energy consumption increased with increasing dietary bermudagrass level and decreasing digestible energy intake.

  • Net flux of nutrients across Splanchnic Tissues in wethers consuming grasses of different sources and physical forms ad libitum
    The British journal of nutrition, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, Z.s. Wang, D.l. Galloway, B. Kouakou, J.e. Rossi
    Abstract:

    Crossbred sheep (n 16, 8.5 months of age and 33 (SE 0.9) kg) were used in a 21 d experiment (2 x 2 factorial) to determine effects on net flux of nutrients across the portal-drained viscera (PDV) and liver of ad libitum consumption of bermudagrass (Cynodon dactylon; B) v. ryegrass (Lolium multiflorum)-wheat (Triticum aestivum; RW) hay, coarsely chopped (CC) or finely ground and pelleted (GP). Crude protein concentrations were 86, 81, 113 and 119 g/kg and neutral-detergent fibre concentrations were 710, 688, 654 and 672 g/kg (dry matter basis) for B-CC, B-GP, RW-CC and RW-GP respectively. Digestible energy intake (6.0, 9.6, 10.2 and 13.8 MJ/d) differed (P < 0.01) with grass source and form, and digestible N intake values were 4.4, 7.0, 8.4 and 14.1 (SEM 0.82) g/d for B-CC, B-GP, RW-CC and RW-GP diets respectively. Consumption of O2 by the PDV (118, 165, 144 and 155 mmol/h) and Splanchnic bed (196, 273, 247 and 266 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively) was greater (P = 0.07) for GP than for CC. The ratio Splanchnic heat energy production: digestible energy intake was greater (P = 0.06) for B than for RW (0.374, 0.300, 0.278 and 0.219 for B-CC, B-GP, RW-CC and RW-GP respectively). alpha-Amino-N release by the PDV (P < 0.01; 11.6, 12.8, 23.0 and 18.7 mmol/h) and uptake by the liver (P = 0.07; 15.2, 6.1, 17.0 and 19.3 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively) were greater for RW than for B. Release of NH3-N by the PDV was greater (P = 0.02) for CC than for GP (12.5, 6.2, 15.7 and 8.9 mmol/h), and hepatic urea-N release differed between grass sources (P = 0.03) and physical forms (P = 0.07; 22.6, 12.7, 31.4 and 24.8 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively). In conclusion, decrease in forage particle size elicited by grinding and pelleting did not affect the difference between grass sources in Splanchnic tissue heat energy production relative to digestible energy intake.

Gilberto Vilmar Kozloski - One of the best experts on this subject based on the ideXlab platform.

  • Impact of a tannin extract on digestibility and net flux of metabolites across Splanchnic Tissues of sheep
    Animal Feed Science and Technology, 2020
    Co-Authors: Tiago Orlandi, Simone Stefanello, Mariana Patricia Mezzomo, Claudio Antonio Pozo, Gilberto Vilmar Kozloski
    Abstract:

    Abstract This study was conducted to quantify the impact of the dietary inclusion of Acacia mearnsii bark extract (TA), a tannin extract, on total tract digestibility and on ammonia, urea and glucose Splanchnic net flux in sheep. The trial was conducted with five Texel male sheep (48 ± 3.2 kg body weight (BW)) surgically implanted with chronic indwelling catheters into one mesenteric, portal and hepatic veins, in two 21-day periods, in a cross-over design. Diet was oat/ryegrass hay, offered ad libitum, plus concentrate offered three times per day at a rate of 14 g/kg BW. The concentrate, composed of soybean meal, cracked corn and wheat bran, included (Tannin) or not (Control) 20 g/kg dry matter (DM) of TA. Plasma flow and net flux through portal-drained viscera (PDV), liver and total Splanchnic Tissues (ST) were measured using four hourly samples, from 14:00 to 17:00, after the 12:00 meal. Total TA concentration in diet of TA treatment averaged 7.7 g/kg DM. The organic matter (OM) intake and digestibility were not affected by TA. The nitrogen (N) intake and fecal excretion, the estimated rumen microbial N flow to the small intestine and the efficiency of microbial protein synthesis (EMPS) were not affected whereas the digestibility of N compounds and the urinary excretion of urea-N were lower (P

  • Oxygen uptake and net flux of metabolites by Splanchnic Tissues of sheep in response to short-term mesenteric infusion of nitrogenous compounds.
    Journal of animal physiology and animal nutrition, 2018
    Co-Authors: Simone Stefanello, Mariana Patricia Mezzomo, Diego Zeni, Rafael Costa Ebling, A. V. Soares, Gilberto Vilmar Kozloski
    Abstract:

    This study was conducted in an attempt to quantify the impact of N load on Splanchnic Tissues metabolism of sheep. The trial was conducted with four male sheep (45 ± 2.5 kg body weight (BW)) surgically implanted with chronic indwelling catheters into the portal, hepatic and mesenteric veins. Blood flow and metabolic flux through portal-drained viscera (PDV), liver and total Splanchnic Tissues (ST) were measured daily following a 4 × 4 Latin Square experimental design, where sheep were continually infused into the mesenteric vein with a physiological saline (0.15 m NaCl) solution during 90 min followed by the infusion, during more 120 min, of either solution: physiological saline (control), 0.250 mNH4 HCO3 , 0.250 m L-alanine or 0.125 m L-arginine, all of them infused at a rate of 1.5 ml/min to provide 375 μmol N/min. During the treatment infusion period, the net removal of ammonia N and the net production of urea N by liver were higher (p 

  • oxygen uptake and net flux of metabolites by Splanchnic Tissues of sheep in response to short term mesenteric infusion of nitrogenous compounds
    Journal of Animal Physiology and Animal Nutrition, 2018
    Co-Authors: Simone Stefanello, Mariana Patricia Mezzomo, Diego Zeni, Rafael Costa Ebling, A. V. Soares, Gilberto Vilmar Kozloski
    Abstract:

    This study was conducted in an attempt to quantify the impact of N load on Splanchnic Tissues metabolism of sheep. The trial was conducted with four male sheep (45 ± 2.5 kg body weight (BW)) surgically implanted with chronic indwelling catheters into the portal, hepatic and mesenteric veins. Blood flow and metabolic flux through portal-drained viscera (PDV), liver and total Splanchnic Tissues (ST) were measured daily following a 4 × 4 Latin Square experimental design, where sheep were continually infused into the mesenteric vein with a physiological saline (0.15 m NaCl) solution during 90 min followed by the infusion, during more 120 min, of either solution: physiological saline (control), 0.250 mNH4 HCO3 , 0.250 m L-alanine or 0.125 m L-arginine, all of them infused at a rate of 1.5 ml/min to provide 375 μmol N/min. During the treatment infusion period, the net removal of ammonia N and the net production of urea N by liver were higher (p < .05) in NH4 HCO3 infused sheep. Based on oxygen consumption, and on average of all treatments, the heat produced by liver and ST was on average 6 and 14 kcal/kg BW representing 16% and 38% of the metabolizable energy intake respectively. Linear relationships between variables indicated that gluconeogenesis and ureagenesis occurred concomitantly and both processes accounted for approximately 50% of total liver energy expenditure, two-thirds of it associated with gluconeogenesis. The results of the current study did not present clear evidence of the expected energy costs associated with ammonia N, alanine or arginine metabolism by liver. However, they indicated that gluconeogenesis is on average a more energy expensive process than ureagenesis.

  • Oxygen consumption by Splanchnic Tissues of sheep under mesenteric load of N compounds.
    Small Ruminant Research, 2018
    Co-Authors: Fernanda Hentz, Simone Stefanello, Diego Zeni, Gilberto Vilmar Kozloski
    Abstract:

    Abstract Four Corriedale castrated male sheep (42 ± 3.4 kg body weight (BW)) surgically implanted with chronic indwelling catheters into the mesenteric, portal and hepatic veins, housed in metabolism cages and fed oat-ryegrass hay at maintenance level were used in a trial conducted to evaluate the effect of the mesenteric load of N compounds on oxygen consumption by the liver. After 17 days of a pre-experimental period, treatments were applied throughout four days following a 4 × 4 Latin Square design, which consisted of mesenteric vein infusion of either NaCl (0.15 M, Control), NH4HCO3 (0.25 M), alanine (0.25 M) or arginine (0.125 M) solution. All solutions were infused continuously at a rate of 2 ml/min during six hours in each experimental period, as to provide a mesenteric N load of 500 umol/min. Blood flow across portal and hepatic veins were estimated through downstream dilution of p-aminohippurate also continuously infused into the mesenteric vein. The blood flow across the portal vein was not affected by treatments whereas the blood flow across the hepatic vein tended (P =  0.09) to be higher in the control treatment. Oxygen consumption by the portal-drained viscera was similar for all treatments whereas oxygen consumption by the liver was higher (P

  • Relationship between level of forage intake, blood flow and oxygen consumption by Splanchnic Tissues of sheep fed a tropical grass forage
    Journal of animal physiology and animal nutrition, 2016
    Co-Authors: Fernanda Hentz, Diego Zeni, Gilberto Vilmar Kozloski, Maurício Veloso Brun, Simone Stefanello
    Abstract:

    Summary 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.

Gerald Lobley - One of the best experts on this subject based on the ideXlab platform.

  • Glutamine metabolism in ovine Splanchnic Tissues: effects of infusion of ammonium bicarbonate or amino acids into the abomasum.
    The British journal of nutrition, 2002
    Co-Authors: Rosa Nieto, Eric Milne, Taketo Obitsu, Alfredo Fernández-quintela, David Bremner, Alexander Graham Calder, Gerald Lobley
    Abstract:

    This study investigates the effects of increased NH3 or amino acid supply on glutamine utilisation and production by the Splanchnic Tissues of fed sheep. Six sheep, prepared with vascular catheters in the aorta, mesenteric, portal and hepatic veins, were fed grass pellets to 1·1 £ energy maintenance requirements. Each treatment involved a 4 d abomasal infusion, of either ammonium bicarbonate (AMM; 23·4mmol/kg 0·75 per min), water (CONT), or a mixture of amino acids that excluded glutamine and glutamate (AA; 46·8mmol amino acid-N/kg 0·75 per min). The treatments simulated nutritional extremes in terms of the balance of absorbed N. Kinetics across the whole gut and the liver were monitored during an intra-jugular infusion of [5- 15 N]glutamine. Blood flow across the whole gut or liver were unaffected by treatment. Both AMM and AA infusions doubled the hepatic release of urea-N compared with CONT (P,0·02). AA infusion decreased arterial glutamine concentration by 26 % (P,0·01) and 23 % (P,0·05) compared with AMM and CONT respectively. Despite this, whole-body glutamine flux was not affected by treatment. In contrast, AMM infusion increased hepatic glutamine production by 40 % compared with CONT (P,0·02). This provided a mechanism to ensure NH3 supply to the periphery was maintained within the normal low physiological levels. Hepatic glutamine utilisation tended to increase during AA infusion, probably to ensure equal inflows of N to the ornithine cycle. Between 6 and 10 % of NH3 absorbed across the digestive tract was derived from the amido-N of glutamine. Overall, Splanchnic glutamine utilisation accounted for 45 ‐ 70 % of whole-body glutamine flux. Glutamine: 15 N kinetics: Ureagenesis: Ammonia: Amino acids: Portal-drained viscera: Liver: Sheep

  • Effect of supply of metabolizable protein on Splanchnic fluxes of nutrients and hormones in lactating dairy cows.
    Journal of dairy science, 2002
    Co-Authors: J.p. Blouin, Christopher K. Reynolds, Gerald Lobley, Jean Bernier, Pascal Dubreuil, Hélène Lapierre
    Abstract:

    Abstract The effect of the supply of metabolizable protein on Splanchnic fluxes of nutrients and hormones was measured in six catheterized late-lactation Holstein cows in a crossover design. Two isonitrogenous diets (16.3% CP), but differing in rumen protein degradability and estimated metabolizable protein (MP) supply (1654g/d, Lo-MP; 1930g/d, Hi-MP) were fed, each over a 35-d experimental period. On d 34 or 35, net fluxes of nutrients and hormones across the portal-drained viscera, the liver, and total Splanchnic Tissues were determined. Portal absorption of total, essential, nonessential, and branched-chain amino acids (AA) increased with the Hi-MP diet. Approximately 76% of the additional metabolizable protein supply was recovered as extra AA-N absorption in the portal vein. Liver removal of AA was not different between diets, and this resulted in a greater net release across the Splanchnic Tissues for the Hi-MP diet. This extra AA supply provided substrates for the observed increased milk protein yield for the Hi-MP diet. Fractional efficiencies of conversion of absorbed individual essential AA into milk protein ranged from 0.42 to 0.68. The corresponding efficiencies for utilization of postSplanchnic AA supply were 0.42 to 1.80. Provision of methionine, phenylalanine, and histidine beyond the liver were similar to outputs in milk protein but the other essential AA were supplied to peripheral Tissues in excess of milk output, indicative of oxidative mechanisms in nonhepatic Tissues. Net fluxes of glucose, NH 3 -N, and urea were not affected by the diets. Neither arterial concentrations of insulin, somatotropin, or IGF-1, nor net transfers across the portal-drained viscera or liver of insulin, were affected by the diets. Although portal release of glucagon was not different between the diets, a smaller proportion was removed by the liver on the Hi-MP diet. Metabolism of AA across the Splanchnic tissue bed is a major determinant of the quantity and the profile of AA delivered to peripheral Tissues.

  • The effect of intake on protein metabolism across Splanchnic Tissues in growing beef steers.
    The British journal of nutrition, 1999
    Co-Authors: Hélène Lapierre, Christopher K. Reynolds, Jean Bernier, Pascal Dubreuil, Chantal Farmer, D. R. Ouellet, Gerald Lobley
    Abstract:

    The contribution of the total Splanchnic tissue (TSP; portal-drained viscera (PDV) plus liver) to whole-body protein metabolism was estimated in relation to intake (0·6, 1·0 and 1·6 〈 maintenance requirements), in six multicatheterized growing beef steers used in a double 3 〈 3 Latin square design. At the end of each 21 d experimental period, [1- 13 C]leucine was infused into a jugular vein (1·05 mmol/h for 5 h, preceded by a priming dose of 1·05 mmol). Arterial, portal and hepatic blood samples were collected hourly during the infusion. The increment in TSP leucine irreversible loss rate (ILR) observed with increasing intake reached significance (P , 0·10) only for PDV, while whole-body ILR increased markedly (P , 0·001) with intake. The relative contribution of TSP to whole-body leucine ILR averaged 44 % (25 % from PDV and 19 % from the liver). Although these proportions were not affected by intake, on an incremental basis more than 70 % of the increase of whole-body leucine ILR between the 0·6 and 1·0 〈 maintenance originated from the changes in TSP ILR, while the corresponding value was below 13 % between 1·0 and 1·6 〈 maintenance. Total whole-body leucine oxidation and fractional oxidation increased (P , 0·05) with intake. Protein retention increased with intake ( P , 0·01), as a result of a greater increase in protein synthesis compared with protein degradation. Protein breakdown had a major impact on protein turnover as 65 % of the protein synthesized was degraded when intake varied from 1· 0t o 1·6 〈 maintenance. Net leucine portal absorption increased (P , 0·001) with intake and represented 1, 16 and 23 % of whole body leucine ILR, for 0·6, 1·0 and 1·6 〈 maintenance, respectively. Although leucine oxidation was not a major component of whole body ILR (9·3‐19·9 %), it represented 69 % of the net available leucine (portal absorption) even at 1·6 〈 maintenance. The lower relative contribution of the TSP to whole-body leucine ILR at higher intake indicates the proportional increase in the metabolic activity of peripheral Tissues as the animals moved into positive protein balance.

  • Protein synthesis in Splanchnic Tissues of sheep offered two levels of intake.
    The British journal of nutrition, 1994
    Co-Authors: Gerald Lobley, Alexmary Connell, Eric Milne, T. A. Ewing
    Abstract:

    Protein synthesis rates were measured in liver and gastrointestinal tract (GIT) sections of fattening sheep offered lucerne (Medicago sativa) pellets at either 1.25 or 2 times energy maintenance. The measurement technique involved a large dose of [1-13C]valine over 60 min. Animals on the higher intake had a larger mass of liver protein (143 v. 100 g, P = 0.02), similar fractional synthesis rates (ks; 22.5 v. 22.1%/d, not significant) and greater absolute amounts of protein synthesis (32 v. 23 g/d; P = 0.016) compared with those on the smaller amount of ration. The ks values and RNA: protein in the GIT sections also tended to increase with food intake. Estimated total GIT protein synthesis was approximately three-fold that in liver and probably constituted 25-35% of whole body synthesis. All Splanchnic Tissues measured had lower translational efficiencies (g protein synthesized/d per g total RNA) than reported for milk-fed and newly-weaned lambs and this may relate to the decline in the rate of protein deposition as lambs progress to the fattening condition.

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  • net flux of nutrients across Splanchnic Tissues in wethers consuming bermudagrass or ryegrass wheat hay supplemented with rumen undegradable protein
    Small Ruminant Research, 1997
    Co-Authors: A. L. Goetsch, K.k. Park, J.e. Rossi, Z.s. Wang, D.l. Galloway, A R Paul, B. Kouakou
    Abstract:

    Crossbred wethers (14, 37 ± 1.5 kg BW and 10 months old) were used in a 21-day experiment (2 × 2 factorial) to determine effects of dietary grass source (tropical vs temperate) on response to rumen undegradable protein supplementation in oxygen consumption by, and net flux of N fractions across, the portal-drained viscera and liver. Bermudagrass (B; 73.1% NDF and 6.2% CP) or ryegrass-wheat (RW; 65.9% NDF and 8.9% CP) hay was supplemented with 53 g day−1 (DM) of soybean meal (S) or 53 g day−1 (DM) of soybean meal plus 70 g day−1 (DM) of a mixture of feedstuffs high in rumen undegradable protein (SR; 46.6% com gluten, 26.7% feather and 26.7% blood meals). Digestible energy intake (9.1, 10.0, 11.3 and 12.1 MJ day−1) was greater (P < 0.01) for RW than for B, and N intake was 12.5, 21.5, 16.5 and 25.3 g day−1 (SE 1.08) for B-S, B-SR, RW-S and RW-SR, respectively. Splanchnic energy use as a percentage of DE intake was less (P = 0.03) for RW vs B (21.4 vs 27.8%). Supplementation with Sr increased (P = 0.04) alpha-amino N release by the portal-drained viscera (6.6, 22.0, 9.8 and 20.6 mmol h−1) and hepatic uptake (10.9, 25.6, 11.2 and 14.3 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively; SE 2.29). Supplementation with Sr increased (P < 0.01) hepatic urea N release (26.7, 48.4, 29.0 and 41.8 mmol h−1) and ammonia N uptake (17.3, 29.7, 23.3 and 26.6 mmol h−1 for B-S, B-SR, RW-S and RW-SR, respectively) more (interaction; P = 0.09 and 0.08, respectively) with B than with RW. In conclusion, these results indicate that DE intake and Splanchnic energy consumption for tropical and temperate grasses may influence metabolic fate of rumen undegradable protein N and, thus, impact potential performance benefits of supplementation. Also, unless forage intake is changed, any improvements in animal performance with rumen undegradable protein supplementation would be through increased N absorption without change in energy available to peripheral Tissues, regardless of grass source.

  • Net flux of nutrients across Splanchnic Tissues in wethers consuming grass hay with or without corn and alfalfa
    Animal Feed Science and Technology, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, J.e. Rossi, Z.s. Wang, D.l. Galloway, B. Kouakou
    Abstract:

    Fourteen crossbred sheep (33 kg body weight, SE = 1; 9 months of age) were used in a 21 day experiment (2 × 2 factorial) to determine if dietary substitution of grain (ground corn; C) for ryegrass-wheat hay (72% neutral detergent fiber and 9% crude protein) alters effects of legume (alfalfa hay: 60% neutral detergent fiber and 15% crude protein; A) substitution on Splanchnic tissue net flux of oxygen, alpha-amino nitrogen, urea and ammonia with ad-libitum consumption. Diets were approximately 100, 75, 75 and 50% grass, 0, 25, 0 and 25% C, and 0, 0, 25 and 25% A for control, C, A and CA treatments, respectively. Dietary inclusion of corn did not affect net fluxes or change effects of alfalfa. Alfalfa substitution did not alter dry matter intake, organic matter digestibility or oxygen consumption by the portal-drained viscera, liver or Splanchnic bed. However, alfalfa increased digestible nitrogen intake (P < 0.01; 6.0, 5.9, 9.8 and 10.3 g per day), hepatic release of urea nitrogen (P = 0.04; 30.6, 22.5, 38.6 and 41.4 mM h−1) and hepatic uptake of ammonia nitrogen (P = 0.04; 12.1, 10.7, 19.3 and 17.6 mM h−1 for control, C, A and CA, respectively) and decreased energy expenditure as a percentage of digestible energy intake by the portal-drained viscera (P = 0.02; 10.8 versus 13.1%) and Splanchnic bed (P = 0.08; 20.8 versus 23.3%). In conclusion, effects of substituting alfalfa for 25% of dietary grass, which was moderate to high in digestibility and moderate in nitrogen concentration, were not influenced by substitution of corn for grass.

  • Oxygen consumption by Splanchnic Tissues in wethers consuming ad libitum different proportions of bermudagrass and ryegrass-wheat.
    Archiv fur Tierernahrung, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, Z.s. Wang, D.l. Galloway, B. Kouakou, J.e. Rossi
    Abstract:

    Crossbred wethers (n = 18, 7.5 month of age and 31 +/- 0.8 kg) were used in a 23-day experiment to determine effects of ad libitum consumption of diets differing in proportions of coarsely chopped bermudagrass and ryegrass-wheat hay (0, 33, 67 and 100%) on oxygen consumption by Splanchnic Tissues. Bermudagrass and ryegrass-wheat were 9 and 13% CP and 78 and 71% NDF, respectively. Intake of dry matter (1.03, 0.92, 0.92 and 0.76 kg/d) and digestible energy (13.5, 10.7, 10.6 and 8.2 MJ/d for 0, 33, 67 and 100% bermudagrass, respectively) changed linearly and cubically (P < 0.05) as bermudagrass level increased. Consumption of oxygen by the portal-drained viscera tended to decrease linearly (P = 0.14) with increasing bermudagrass (182, 154, 156 and 137 mM/h), and hepatic oxygen consumption decreased linearly (P < 0.05) and changed cubically (P = 0.07; 150, 113, 116 and 103 mM/h for 0, 33, 67 and 100% bermudagrass, respectively). Splanchnic tissue energy consumption expressed as a percentage of digestible energy intake increased linearly (P = 0.08) with increasing bermudagrass (24.0, 27.6, 28.6 and 33.2% for 0, 33, 67 and 100% bermudagrass, respectively). In conclusion, the level rather than presence alone of different grass sources consumed ad libitum affected energy use by the Splanchnic bed, and as a percentage of digestible energy intake Splanchnic bed energy consumption increased with increasing dietary bermudagrass level and decreasing digestible energy intake.

  • Net flux of nutrients across Splanchnic Tissues in wethers consuming grasses of different sources and physical forms ad libitum
    The British journal of nutrition, 1997
    Co-Authors: A. L. Goetsch, A. R. Patil, K.k. Park, Z.s. Wang, D.l. Galloway, B. Kouakou, J.e. Rossi
    Abstract:

    Crossbred sheep (n 16, 8.5 months of age and 33 (SE 0.9) kg) were used in a 21 d experiment (2 x 2 factorial) to determine effects on net flux of nutrients across the portal-drained viscera (PDV) and liver of ad libitum consumption of bermudagrass (Cynodon dactylon; B) v. ryegrass (Lolium multiflorum)-wheat (Triticum aestivum; RW) hay, coarsely chopped (CC) or finely ground and pelleted (GP). Crude protein concentrations were 86, 81, 113 and 119 g/kg and neutral-detergent fibre concentrations were 710, 688, 654 and 672 g/kg (dry matter basis) for B-CC, B-GP, RW-CC and RW-GP respectively. Digestible energy intake (6.0, 9.6, 10.2 and 13.8 MJ/d) differed (P < 0.01) with grass source and form, and digestible N intake values were 4.4, 7.0, 8.4 and 14.1 (SEM 0.82) g/d for B-CC, B-GP, RW-CC and RW-GP diets respectively. Consumption of O2 by the PDV (118, 165, 144 and 155 mmol/h) and Splanchnic bed (196, 273, 247 and 266 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively) was greater (P = 0.07) for GP than for CC. The ratio Splanchnic heat energy production: digestible energy intake was greater (P = 0.06) for B than for RW (0.374, 0.300, 0.278 and 0.219 for B-CC, B-GP, RW-CC and RW-GP respectively). alpha-Amino-N release by the PDV (P < 0.01; 11.6, 12.8, 23.0 and 18.7 mmol/h) and uptake by the liver (P = 0.07; 15.2, 6.1, 17.0 and 19.3 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively) were greater for RW than for B. Release of NH3-N by the PDV was greater (P = 0.02) for CC than for GP (12.5, 6.2, 15.7 and 8.9 mmol/h), and hepatic urea-N release differed between grass sources (P = 0.03) and physical forms (P = 0.07; 22.6, 12.7, 31.4 and 24.8 mmol/h for B-CC, B-GP, RW-CC and RW-GP respectively). In conclusion, decrease in forage particle size elicited by grinding and pelleting did not affect the difference between grass sources in Splanchnic tissue heat energy production relative to digestible energy intake.

  • Influence of grass source and legume level on net flux of nutrients across Splanchnic Tissues in sheep
    Small Ruminant Research, 1996
    Co-Authors: A. R. Patil, A. L. Goetsch, K.k. Park, D.l. Galloway, B. Kouakou, Zelpha B. Johnson
    Abstract:

    Abstract Crossbred catheterized wethers (20 months old; 45 kg BW, SE 0.7) consumed ad libitum warm ((W) bermudagrass; Cynodon dactylon ) or cool ((C) ryegrass-wheat mixture; Lolium multiflorum and Triticum aestivum , respectively) season grass hay with 0%, 20% or 40% legume hay ((L) alfalfa; Medicago sativa ). Legume, W and C had 54%, 80% and 68% NDF and 17%, 14% and 10% CP, respectively (DM basis). Apparent digestible energy intake was 3.22, 3.42, 3.66, 3.23, 3.57 and 3.67 (SE 0.208) Mcal day −1 , and apparent digestible N intake was 17.6, 20.2, 23.4, 10.1, 14.0 and 17.3 (SE 1.09) g day −1 for W:0% L, W:20% L, W:40% L, C:0% L, C:20% L and C:40% L, respectively. Splanchnic bed oxygen consumption (306, 364, 380, 261, 316 and 383 mmol h −1 ; P = 0.02) and portal-drained viscera (PDV) releases of alpha-amino N (24.8, 37.6, 38.6, 24.4, 38.4 and 41.7 mmol h −1 ; P = 0.04) and propionate (14.4, 19.4, 20.5, 14.3, 23.6 and 21.1 mmol h −1 for W:0% L, W:20% L, W:40% L, C:0% L, C:20% L and C:40% L, respectively; P = 0.08) were greater with L than without. However, Splanchnic bed net releases of alpha-amino N and glucose were similar among treatments. In conclusion, dietary L inclusion had similar effects on Splanchnic tissue oxygen consumption and net fluxes of nutrients regardless of grass source, which differed in concentrations of NDF and CP but not in apparent digestible energy intake. These results suggest that potential improvement of animal performance by substituting 20% or 40% legume for warm or cool season grass, consumed ad libitum by mature ruminants, would not be attributable to change in extra-Splanchnic tissue availabilities of energy (based on the difference between apparent digestible energy intake and Splanchnic tissue energy consumption), amino acids or glucose.