Energy metabolism by splanchnic tissues of mature sheep fed varying levels of lucerne hay cubes

The objective of this study was to determine the pattern of energy metabolites net flux across the portal-drained viscera (PDV) and total splanchnic tissues (TSP) in mature sheep fed varying levels of lucerne hay cubes. Four Suffolk mature sheep (61.4 ± 3.6 kg BW) surgically fitted with multi-catheters were fed four levels of dry matter intake (DMI) of lucerne hay cubes ranging from 0.4- to 1.6-fold the metabolizable energy (ME) requirements for maintenance. Six sets of blood samples were simultaneously collected from arterial and venous catheters at 30-min intervals. With increasing DMI, apparent total tract digestibility increased linearly and quadratically for dry matter (P < 0.05), quadratically (P < 0.05) with a linear tendency (P < 0.1) for organic matter and tended to increase quadratically (P < 0.1) for NDF. PDV release of volatile fatty acids (VFA) and β-hydroxybutyric acid was relatively low at 0.4 M and then linearly increased (P < 0.05) with increasing DMI. Net PDV flux of non-esterified fatty acids showed curvilinear decrease from 0.4 to 1.2 M and then increased at 1.6 M. The respective proportions of each VFA appearing in the portal blood differed (P < 0.05) with DMI and this difference was more obvious from 0.4 to 0.8 M than from 0.8 to 1.6 M. Heat production, as a percentage of ME intake (MEI), decreased linearly (P < 0.05) with increasing DMI accounting for 37%, 21%, 16% and 13% for PDV and 62%, 49%, 33% and 27% for TSP at 0.4, 0.8, 1.2 and 1.6 M, respectively. As a proportion of MEI, total energy recovery including heat production, decreased linearly with increasing DMI (P < 0.05) accounting for 113%, 83%, 62% and 57% for PDV and 140%, 129%, 86% and 83% for TSP at 0.4, 0.8, 1.2 and 1.6 M, respectively. Regression analysis revealed a linear response between MEI (MJ/day per kg BW) and total energy release (MJ/day per kg BW) across the PDV and TSP, respectively. However, respective contributions of energy metabolites to net energy release across the PDV and TSP were highly variable among treatments and did not follow the same pattern of changes in DMI.     

Metabolic flux measurements across portal drained viscera, liver, kidney and hindquarter in mice

A method was developed to measure metabolic fluxes across either portally-drained viscera (PDV) and liver or kidney and hindquarter (HQ) in anesthetized mice. The method includes a primed-constant infusion of ketamine-medetomidine anaesthesia to stabilize the mice for the surgical procedures. For measurement of metabolic fluxes across PDV and liver, blood sampling catheters were inserted in the carotid artery, portal vein and hepatic vein and infusion catheters in the jugular vein and mesenteric vein. For measurement of metabolic flux across kidney and HQ, blood sampling catheters were inserted in the carotid artery, renal vein and caval vein and infusion catheters in the jugular vein and abdominal aorta. 14C-PAH was infused to enable plasma flow measurement using an indicator dilution method. In addition, we developed a blood sampling procedure without waste of blood. We measured plasma flow and metabolic fluxes across PDV, liver, kidney and HQ. Mean plasma flow in post-absorptive mice was: PDV: 0.9+/-0.2, liver: 1.2+/-0.3, kidney: 1.0+/-0.1, HQ: 1.1+/-0.3 ml/10 g body weight (b.w.)/min. Significant glutamine release by the HQ and uptake of glutamine by the kidney and PDV was observed. In PDV, citrulline is produced from glutamine and is in turn used by the kidney for the production of arginine. In conclusion, the described model enables measurement of metabolic fluxes across PDV, liver, kidney and HQ in mice. The availability of such a small animal model allows the potential for measuring metabolic parameters in transgenic and knockout mice, and therefore may lead to an important refinement in metabolic research.     

Glucagon-like peptide-2 (GLP-2) increases net amino acid utilization by the portal-drained viscera of ruminating calves

Glucagon-like peptide-2 (GLP-2) increases small intestinal mass and blood flow in ruminant calves, but its impact on nutrient metabolism across the portal-drained viscera (PDV) and liver is unknown. Eight Holstein calves with catheters in the carotid artery, mesenteric vein, portal vein and hepatic vein were paired by age and randomly assigned to control (0.5% bovine serum albumin in saline; n = 4) or GLP-2 (100 μg/kg BW per day bovine GLP-2 in bovine serum albumin; n = 4). Treatments were administered subcutaneously every 12 h for 10 days. Blood flow was measured on days 0 and 10 and included 3 periods: baseline (saline infusion), treatment (infusion of bovine serum albumin or 3.76 μg/kg BW per h GLP-2) and recovery (saline infusion). Arterial concentrations and net PDV, hepatic and total splanchnic fluxes of glucose, lactate, glutamate, glutamine, β-hydroxybutyrate and urea-N were measured on days 0 and 10. Arterial concentrations and net fluxes of all amino acids and glucose metabolism using continuous intravenous infusion of [U¹³-C]glucose were measured on day 10 only. A 1-h infusion of GLP-2 increased blood flow in the portal and hepatic veins when administered to calves not previously exposed to exogenous GLP-2, but after a 10-day administration of GLP-2 the blood flow response to the 1-h GLP-2 infusion was substantially attenuated. The 1-h GLP-2 infusion also did not appreciably alter nutrient fluxes on either day 0 or 10. In contrast, long-term GLP-2 administration reduced arterial concentrations and net PDV flux of many essential and non-essential amino acids. Despite the significant alterations in amino acid metabolism, glucose irreversible loss and utilization by PDV and non-PDV tissues were not affected by GLP-2. Fluxes of amino acids across the PDV were generally reduced by GLP-2, potentially by increased small intestinal epithelial growth and thus energy and amino acid requirements of this tissue. Increased PDV extraction of glutamine and alterations in PDV metabolism of arginine, ornithine and citrulline support the concept that GLP-2 influences intestine-specific amino acid metabolism. Alterations in amino acid metabolism but unchanged glucose metabolism suggests that the growth effects induced by GLP-2 in ruminants increase reliance on amino acids preferentially over glucose. Thus, GLP-2 increases PDV utilization of amino acids, but not glucose, concurrent with stimulated growth of the small intestinal epithelium in post-absorptive ruminant calves.     

Somatotropin-induced protein anabolism in hindquarters and portal-drained viscera of growing pigs

To differentiate the effect of somatotropin (ST) treatment on protein metabolism in the hindquarter (HQ) and portal-drained viscera (PDV), growing swine (n = 20) treated with ST (0 or 150 microg x kg(-1) x day(-1)) for 7 days were infused intravenously with NaH(13)CO(3) and [(2)H(5)]phenylalanine and enterally with [1-(13)C]phenylalanine while in the fed state. Arterial, portal venous, and vena cava whole blood samples, breath samples, and blood flow measurements were obtained for determination of tissue and whole body phenylalanine kinetics under steady-state conditions. In the fed state, ST treatment decreased whole body phenylalanine flux, oxidation, and protein degradation without altering protein synthesis, resulting in an improvement in whole body net protein balance. Blood flow to the HQ (+80%), but not to the PDV, was increased with ST treatment. In the HQ and PDV, ST increased phenylalanine uptake (+44 and +23%, respectively) and protein synthesis (+43 and +41%, respectively), with no effect on protein degradation. In ST-treated and control pigs, phenylalanine was oxidized in the PDV (34-43% of enteral and arterial sources) but not the HQ. In both treatment groups, dietary (40%) rather than arterial (10%) extraction of phenylalanine predominated in gut amino acid metabolism, whereas localized blood flow influenced HQ amino acid metabolism. The results indicate that ST increases protein anabolism in young, growing swine by increasing protein synthesis in the HQ and PDV, with no effect on protein degradation. Differing results between the whole body and the HQ and PDV suggest that the effect of ST treatment on protein metabolism is tissue specific.     

Jejunal morphology and blood metabolites in tail biting,victim and control pigs

Tail biting has several identified feeding-related risk factors. Tail biters are often said to be lighter and thinner than other pigs in the pen, possibly because of nutrition-related problems such as reduced feed intake or inability to use nutrients efficiently. This can lead to an increase in foraging behavior and tail biting. In this study, a total of 55 pigs of different ages were selected according to their tail-biting behavior (bouts/hour) and pen-feeding system to form eight experimental groups: tail-biting pigs (TB), victim pigs (V) and control pigs from a tail-biting pen (Ctb) and control pen (Cno) having either free access to feed with limited feeding space or meal feeding from a long trough. After euthanasia, a segment of jejunal cell wall was cut from 50 cm (S50) and 100 cm (S100) posterior to the bile duct. Villus height, crypt depth and villus : crypt ratio (V : C) were measured morphometrically. Blood serum concentration of minerals and plasma concentration of amino acids (AA) was determined. Villus height was greater in Cno than Ctb pigs in the proximal and mid-jejunum (P < 0.05), indicative of better ability to absorb nutrients, and increased with age in the proximal jejunum (P < 0.001). Serum mineral concentration of inorganic phosphate (P_i) and calcium (Ca) was lower in Ctb compared with Cno pigs, and that of P_i in V compared with all the other pigs. Many non-essential AA were lower in pigs from tail-biting pens, and particularly in victim pigs. Free access feeding with shared feeding space was associated with lower levels of essential AA in blood than meal feeding with simultaneous feeding space. Our data suggest that being a pig in a tail-biting pen is associated with decreased jejunal villus height and blood AA levels, possibly because of depressed absorption capacity, feeding behavior or environmental stress associated with tail biting. Victim pigs had lower concentrations of AA and P_i in plasma, possibly as a consequence of being bitten.     

Effects of forage intake level on nitrogen net flux by portal-drained viscera of mature sheep with abomasal infusion of an amino acid mixture

This study aimed to investigate the pattern of nitrogen (N) metabolites flux across the portal-drained viscera (PDV) of mature sheep over a wide range of forage intake, and to determine the effect of dry matter intake (DMI) on the PDV recovery of an abomasally infused amino acids (AA) mixture. Four Suffolk mature sheep (61.4 ± 3.6 kg BW) surgically fitted with abomasal cannulae and multi-catheters were fed four levels of DMI of lucerne hay cubes ranging from 0.4 to 1.6 fold the metabolizable energy requirements for maintenance. Each period lasted for 17 days: 7 days for diet adaptation, 5 days for measurement of N balance and N metabolites flux under basal pre-infusion conditions (basal phase) and 5 days for determining the recovery of the infused AA (584 mmol/day) across the PDV (infusion phase). Six sets of blood samples were collected on the last day of both basal and infusion phases. Increasing DMI increased portal release of AA and enhanced N retention. At 0.4 M and as a proportion of digested N, there was a marked drop in total AA-N release accompanied by greater ammonia-N release and urea-N uptake across the PDV. The incremental recovery ratio of infused AA across the PDV was altered with increasing DMI accounting for 0.88, 1.12, 1.23 and 1.31 at 0.4, 0.8, 1.2 and 1.6 M, respectively. In addition, across the individual AA, the net portal recovery ratio of infused methionine and valine increased linearly (P < 0.05) while that of phenylalanine, branched-chain AA and total essential AA tended to increase linearly (P < 0.10) with increasing DMI. These results indicated that DMI affects the net portal recovery of AA available in the small intestine of mature sheep.     

Tetraethylammonium and p-aminohippurate as clearance markers for renal plasma flow in the rat during saline and glucose infusion.

Renal plasma clearances (C) of 14C-tetraethylammonium (TEA) and p-aminohippurate (PAH) as estimates of arterial renal plasma flow (ARPF) were evaluated in anesthetized rats during control conditions and during intravenous glucose infusion. Venous renal blood flow was measured directly by means of a servo-controlled pump, keeping the renal venous pressure constant. Arteriovenous extraction fractions (E = 1 - P(renal venous)/P(renal arterial)) for PAH averaged 88.3 +/- (SE) 0.8% in control rats and 82.0 +/- 0.9% in glucose-infused rats (p less than 0.001); E(TEA) averaged 92.0 +/- 0.6 and 90.1 +/- 0.6%, respectively (p less than 0.05). Under both experimental conditions, (C/E)PAH did not differ significantly from ARPF, while (C/E)TEA underestimated ARPF; the rate of extraction of TEA exceeded the rate of excretion by 15-20%, probably due to accumulation of TEA in renal tissue. It is concluded that, when corrected for E, C(PAH) is in general a more accurate estimate for ARPF than C(TEA). However, under conditions involving changes in plasma glucose levels C(TEA) may provide a better estimate of the effective renal plasma flow than C(PAH).     

Effects of resistant starch on behaviour,satiety-related hormones and metabolites in growing pigs

Resistant starch (RS) has been suggested to prolong satiety in adult pigs. The present study investigated RS-induced changes in behaviour, satiety-related hormones and metabolites in catheterized growing pigs to explore possible underlying mechanisms for RS-induced satiety. In a cross-over design with two 14-day periods, 10 pigs (initial BW: 58 kg) were assigned to two treatments comprising diets containing either 35% pregelatinized starch (PS) or 34% retrograded starch (RS). Diets were isoenergetic on gross energy. Pigs were fed at 2.8× maintenance. Postprandial plasma response of satiety-related hormones and metabolites was measured at the end of each period using frequent blood sampling. Faecal and urinary energy losses were measured at the end of each period. Behaviour was scored 24 h from video recordings using scan sampling. Energy digestibility and metabolizability were ~6% lower in RS compared with PS diet (P<0.001), and metabolizable energy (ME) intake was ~3% lower in RS-fed than in PS-fed pigs (P<0.001). RS-fed pigs showed less feeder-directed (P=0.001) and drinking (P=0.10) behaviours than PS-fed pigs throughout the day. Postprandial peripheral short-chain fatty acid (SCFA) levels were higher in RS-fed than in PS-fed pigs (P<0.001). Postprandial glucose and insulin responses were lower in RS-fed than in PS-fed pigs (P<0.001). Triglyceride levels were higher in RS-fed than in PS-fed pigs (P<0.01), and non-esterified fatty acid levels did not differ between diets (P=0.90). Glucagon-like peptide-1 (GLP-1) levels were lower in RS-fed than in PS-fed pigs (P<0.001), and peptide tyrosine tyrosine (PYY) levels did not differ between diets (P=0.90). Blood serotonin levels were lower (P<0.001), whereas monoamine oxidase activity (P<0.05) and tryptophan (P<0.01) levels were higher in RS-fed than in PS-fed pigs. Despite a lower ME intake, RS seemed to prolong satiety, based on behavioural observations. Possible underlying mechanisms for RS-induced satiety include increased 24 h plasma SCFA levels, and decreased postprandial glucose and insulin responses. GLP-1 and PYY seemed not to play a role in RS-induced satiety. Low blood serotonin levels in RS-fed pigs suggested a difference in intestinal serotonin release between treatments. Increased postprandial plasma triglyceride levels corresponded with increased SCFA levels, but it is unclear whether triglycerides may have signalled satiety in RS-fed pigs.     

Effect of harvesting period on the nutritive value of rice grass (Echinochloa sp.) hay given as sole diet to lambs

Data regarding the influence of maturity within the vegetative stage of tropical grasses on forage quality are limited and conflicting. The change in chemical composition of rice grass (Echinochloa sp.) hay harvested at 32, 46, 72 and 90 days of regrowth, and its effect on intake, digestibility, ruminal fermentation, rumen microbial protein synthesis (Experiment 1) and splanchnic oxygen uptake (Experiment 2) by lambs was evaluated. Except intake of indigestible neutral detergent fibre (NDF) which was similar for all treatments, intake of all hay components and the apparent digestibility of dry matter, organic matter (OM), NDF, N, as well as OM and N true digestibility, N retention and rumen microbial protein synthesis decreased linearly (P < 0.05) with increased regrowth age. Rumen fluid pH, ammonia N and peptide concentrations were similar for all treatments while sugars and amino acid concentrations decreased linearly with increased regrowth age of rice grass (P < 0.05). Passage rate of particles through reticulum-rumen (PRrr) was quadratically related (P < 0.05) to regrowth age. The highest PRrr and, consequently, the lowest retention time in the reticulum-rumen were obtained at 72 days of regrowth. There was a quadratic effect (P < 0.05) on net portal-drained viscera (PDV) flux of oxygen and heat production, while OM intake, portal blood flow and heat production as proportion of digestible energy (DE) intake were not affected by the increased regrowth age of rice grass. The highest means of oxygen uptake and heat production by PDV tissues were in 72 days treatment. In the whole splanchnic metabolism assay neither hay intake nor blood flow, oxygen uptake or heat production were affected by forage regrowth age. In conclusion, the nutritive value of rice grass hay decreased as regrowth age increased from 32 to 90 days due to decrease both OM intake and digestibility.     

Effects of low-protein diets supplemented with indispensable amino acids on growth performance,intestinal morphology and immunological parameters in 13 to 35 kg pigs

The objective of this study was to determine if a moderate or high reduction of dietary CP, supplemented with indispensable amino acids (IAA), would affect growth, intestinal morphology and immunological parameters of pigs. A total of 40 barrows (initial BW=13.50±0.50 kg, 45±2 day of age) were used in a completely randomized block design, and allocated to four dietary treatments containing CP levels at 20.00%, 17.16%, 15.30% and 13.90%, respectively. Industrial AA were added to meet the IAA requirements of pigs. After 4-week feeding, blood and tissue samples were obtained from pigs. The results showed that reducing dietary CP level decreased average daily gain, plasma urea nitrogen concentration and relative organ weights of liver and pancreas (P<0.01), and increased feed conversion ratio (P<0.01). Pigs fed the 13.90% CP diet had significantly lower growth performance than that of pigs fed higher CP at 20.00%, 17.16% or 15.30%. Moreover, reducing dietary CP level decreased villous height in duodenum (P<0.01) and crypt depth in duodenum, jejunum and ileum (P<0.01). The reduction in the dietary CP level increased plasma concentrations of methionine, alanine (P<0.01) and lysine (P<0.05), and decreased arginine (P<0.05). Intriguingly, reducing dietary CP level from 20.00% to 13.90% resulted in a significant decrease in plasma concentration of IgG (P<0.05), percentage of CD3⁺T cells of the peripheral blood (P<0.01), also down-regulated the mRNA abundance of innate immunity-related genes on toll-like receptor 4, myeloid differentiation factor 88 (P<0.01) and nuclear factor kappa B (P<0.05) in the ileum. These results indicate that reducing dietary CP level from 20.00% to 15.30%, supplemented with IAA, had no significant effect on growth performance and had a limited effect on immunological parameters. However, a further reduction of dietary CP level up to 13.90% would lead to poor growth performance and organ development, associated with the modifications of intestinal morphology and immune function.     

Betaine increases net portal absorption of volatile fatty acids in Iberian pigs

Betaine is an osmolyte with the potential to increase volatile fatty acids (VFAs) production and hence improve intestinal health.The present study investigated how betaine affects portal and arterial concentrations and net portal absorption (NPA) of VFA in growing Iberian pigs. Eight 30 kg BW Iberian growing barrows with indwelling catheters in portal vein, ileal vein and carotid artery were randomly assigned to a control diet or a diet supplemented with 0.5% betaine. Para-aminohippuric acid was infused into the ileal vein as a marker to determine portal blood flow using the dilution method. Blood samples were simultaneously taken from the carotid artery and portal vein at −60, 60, 120, 180, 240, 300 and 360 min after feeding 1 200 g of the diet. The NPA of VFA (acetate, propionate, butyrate, valerate, isobutyrate and caproate) was determined by multiplying the porto-arterial plasma concentration differences by portal plasma flow. Betaine increased NPA of acetate (1.44 fold; P < 0.001) and total VFA (0.55 fold; P < 0.001) while decreased NPA of propionate (−0.38 fold; P < 0.05) and valerate (−1.46 fold; P < 0.05) compared with control pigs. Estimated heat production potentially derived from NPA of VFA accounted for 0.20–0.27 of metabolizable energy for maintenance. Acetate and propionate accounted for most of the total VFA estimated heat production (0.83–0.89). Regarding bacterial communities, betaine apparently did not change the DNA abundance of fecal total bacteria, Lactobacillus, Bifidobacterium, Enterobacteriaceae, Bacteroides and the Clostridium clusters I, IV and XIV. In conclusion, betaine increased portal appearance and NPA of VFA, contributing to cover maintenance energy requirements.     

A sandwich enzyme-linked immunosorbent assay for adducts of polycyclic aromatic hydrocarbons with human serum albumin

Adducts of benzo[a]pyrene-diolepoxide (BPDE) with blood nucleophiles have been used as biomarkers of exposure to polycyclic aromatic hydrocarbons (PAHs). The most popular such assay is a competitive enzyme-linked immunosorbent assay (ELISA) that employs monoclonal antibody 8E11 to detect benzo[a]pyrene tetrols following hydrolysis of BPDE adducts from lymphocyte DNA or human serum albumin (HSA). Here we used 8E11 as the capture antibody in a sandwich ELISA to detect BPDE-HSA adducts directly in 1-mg samples of HSA or 20 μl of serum/plasma. The assay employs an anti-HSA antibody for detection, and this is amplified by an avidin/biotinylated horseradish peroxidase complex. The sandwich ELISA has advantages of specificity and simplicity and is approximately 10 times more sensitive than the competitive ELISA. To validate the assay, HSA samples were assayed from three populations with known high PAH exposures (coke oven workers), medium PAH exposures (steel factory control workers), and low PAH exposures (volunteer subjects) (n = 30). The respective geometric mean levels of BPDE-HSA adducts—67.8, 14.7, and 1.93 ng/mg HSA (1010, 220, and 28.9 fmol BPDE equiv/mg HSA)—were significantly different (P < 0.05). The sandwich ELISA will be useful for screening PAH exposures in large epidemiologic studies and can be extended to other adducts for which capture antibodies are available.     

Clinical assay of four thiol amino acid redox couples by LC–MS/MS: Utility in thalassemia

The total concentrations of four sulfur amino acid (SAA) metabolite redox couples (reduced and oxidized forms of homocysteine, cysteine, glutathione, and cysteinylglycine) in human blood are assayed with a simple and sensitive method by liquid chromatography–electrospray positive ionization–tandem mass spectrometry. To prevent ex vivo thiol oxidation, iodoacetamide (IAM) is used immediately following the blood draw. To selectively enrich for S-carboxyamidomethylated SAA, and other cationic amino acids metabolites, proprietary strong cation-exchange solid phase extraction tips are used. Analytes are further derivatized with isopropylchloroformate (IPCF) to esterify the amino and the carboxylic groups. Double derivatization with IAM and IPCF improves the reverse phase liquid chromatography separation of SAA metabolites. The use of detection mode of multiple-reaction monitoring (MRM) allows sensitive and specific simultaneous detection of SAA. The internal standards used to account for the matrix effects of human plasma and erythrocytes were plant glutathione analogue, homoglutathione, and stable isotopes of cystine and homocystine. The method was validated for its linearity, accuracy, and precision. Excellent linearity of detection (r² > 0.98) was observed over relevant ranges for plasma and erythrocyte samples, and the limits of detection were established to be between 5 and 20 nM. Relative standard deviations were <9% for within-day variations and <15% for between-day variations. The method was used to assess thiol redox states in plasma and erythrocytes isolated from healthy subjects and thalassemia patients.     

The effects of air dried poultry manure on performance,organ weights and haematological measurements of weaner pigs reared in the tropics

Sixty-three Large White and Large White × Landrace pigs, initially weighing approximately 10 kg, were allocated to 9 groups of 7 pigs each with equal constant sex and breed ratios. These were fed on one of 9 diets containing 0, 5 and 10% dried poultry manure (DPM) at three levels of protein (17, 19 and 21%) for 16 weeks. Growth rate, feed intake and nutrient digestibility were measured. At the end, all animals were slaughtered, blood samples collected for haematological studies, fresh organ weights recorded and tissue and organs examined for evidence of pathological conditions. Growth rate was not significantly influenced by DPM levels but was significantly (P < 0.05) influenced by protein levels. Apparent digestibility of nutrients was not significantly influenced by protein or DPM levels. Increasing DPM levels significantly increased feed consumption and worsened feed/gain ratio. Organ weights were not significantly influenced by treatments but total white blood cells, percentage banded neutrophils, segmented neutrophils and eosinophils differed significantly (P < 0.05) among groups. The banded and segmented neutrophils were higher, while the lymphocytes were lower, than the normal values; this suggests the presence of pathogenic organisms in pigs fed on these DPM diets.     

Effect of dietary fish oil on selected inflammatory markers in pigs

The present study tested a hypothesis that dietary fish oil (eicosapentaenoic acid+docosahexaenoic acid) in a commonly achievable dose ameliorates a systemic inflammation in pigs. Two groups of pigs of 16 animals each were fed a diet with either 2.5% of fish oil (F) or a control diet with 2.5% of palm oil (P). After 70 days of fattening, eight F and eight P pigs were challenged (F⁺; P⁺) i.v. by lipopolysaccharide. After 3 h, all pigs were sacrificed and blood, liver and visceral adipose tissue (VAT) samples were taken. No significant effect (P>0.05) of dietary oil on the feed intake and daily weight gain was found out. Less neutrophils (16.8% v. 28.8%; P<0.05) were found in the F⁺-leukocytes of the peripheral blood; F⁺ pigs had lower (P<0.05) percentage of the swine leukocyte antigen-D-related CD163⁺ (SLA-DR⁺ CD163⁺) macrophages in the VAT (15.4% v. 21.8%) and lower expression of the SLA-DR-CD163⁺ surface molecules of the VAT macrophages. No difference (P>0.05) between F⁺ and P⁺ pigs in the peroxisome proliferator-activated receptor γ, GPR120, Adipor1 and Adipor2 (adiponectin receptor) gene expression, respectively, was established; plasma adiponectin was the same (21.1 ng/ml) in F⁺ and P⁺ pigs. In comparison with the P⁺ pigs, increased expression of the lipopolysaccharide-binding protein (LBP) gene and intercellular adhesion molecule 1 (ICAM1) gene was found out in the liver of the F⁺ pigs; expression of the tumor necrosis factor α (TNFα) gene was higher in the liver but lower in the VAT of the F⁺ pigs (P<0.05). The F⁺ pigs had higher (P<0.05) plasma concentration of both anti-inflammatory cytokine interleukin-4 (0.46 v. 0.04 ng/ml) and pro-inflammatory TNF-α (13.41 v. 7.72 ng/ml). It was concluded that dietary fish oil at the tested amount had a negligible effect on expression of the evaluated receptor genes and plasma adiponectin, and had an ambiguous effect on expression of cytokine genes and plasma cytokine levels.     

Contribution of erythrocytes and plasma in threonine and lysine transfer across the portal drained viscera and the liver in pigs. Effect of threonine and lysine dietary supply

Contributions of erythrocytes and plasma to threonine and lysine transport across the PDV and the liver were determined in growing pigs successively fed a threonine deficient diet and a control well-balanced diet (experiment 1) or a lysine deficient or a well-balanced diet (experiment 2). The animals were surgically prepared for insertion of chronic catheters in the mesenteric vein (MV), the portal vein (PV), a hepatic vein (HV) and the carotid artery (CA). Plasma and whole blood AA concentrations in PV, HV and CA and PV and HV blood flows were determined during 6 hours of para-aminohippuric acid constant infusion. During this period the pigs were continuously fed (1 meal per hour). The contribution of plasma to lysine and threonine transport was higher in pigs fed the well balanced diets. More than 50% of threonine and lysine appearing in the PV and in the HV are transported by the plasma. Our results suggest that erythrocytes are probably little involved in lysine and threonine transfer across the liver and digestive tract of pig continuously fed.     

Starvation-induced changes in metabolic rate, blood flow, and regional energy expenditure in rats

Starvation results in an energy-conserving reduction in metabolic rate that has features of an adaptive response. Tissue and organ sites of this response were investigated by examining the effects of starvation for 5 d on tissue blood flow (microsphere method) and regional arteriovenous O2 differences ((a-v)O2) in conscious rats resting quietly at 28 degrees C. Comparison was with fed and overnight-fasted animals. Whole body resting metabolic rates (MR), colonic temperatures (Tc), and tissue weights were also determined. Quantitative changes in energy expenditure (as O2 consumption) were obtained for two regions: the portal-drained viscera (PDV) and the hindquarters (HQ). Fasting overnight resulted in increased blood flow to white adipose tissue (WAT) and decreased flow to the brain, PDV, testes, and skin; however, MR, Tc, the two regional ((a-v)O2, and the weights of most tissues were not significantly altered. In comparison with overnight fasting, starvation for 5 d resulted in a 13% reduction in body weight, weight loss in many tissues and organs, a 26% reduction in MR, a decline of 0.5 degree C in Tc, decreased (a-v)O2 across both the PDV and HQ, reduced cardiac output, and decreased blood flow to the heart, PDV, skin, WAT, leg muscle, HQ, and the musculoskeletal body as a whole. Utilization of O2 by the PDV and HQ (flow X (a-v)O2) declined by amounts that accounted for 22 and 18%, respectively, of the reduction in MR. The reductions in cardiac output (18%) and heart blood flow (36%) indicate that the heart also made a contribution to energy conservation (roughly estimated as 5%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Diet supplemented either with dried chicory root or chicory inulin significantly influence kidney and liver mineral content and antioxidative capacity in growing pigs

According to the Regulation No. 1831/2003 of the European Parliament and European Union Council, the use of antibiotics as a dietary supplements has been prohibited. It seems that the administration of prebiotics, instead of antibiotics, into the pig's diet, may regulate the intestinal microbiota and has a long-term health-related impact on the host. Inulin-type fructans can stimulate mineral absorption from the gut. Additionally, it may regulate energy metabolism and activate enzymatic mechanisms preventing oxidative stress. The goal of the present study was to estimate the influence of dietary supplementation with dried chicory root or native chicory inulin on 1) liver histology; 2) liver and kidney lipid metabolism indices, activity of selected enzymes, concentration of macro- and micronutrients and heavy metals; 3) blood plasma, liver and kidney oxidative stress biomarkers and 4) blood plasma water–electrolyte homeostasis indices in growing pigs. The nutritional study was conducted on 24 piglets assigned to 3 dietary groups (n = 8): control (C) fed a basal diet and two experimental groups receiving basal diet supplemented with 2% of inulin (IN) either 4% of dried chicory root (CR). The animals were fed with a group-specific diets for 40 days and then subjected to euthanasia. Subsequently, blood, liver and kidney samples were harvested for further processing. In the control and experimental groups, no apparent morphological abnormalities in the liver tissues were seen. The percent of periodic acid Schiff positive glycogen liver cells was significantly lower in the CR group as compared to C and IN groups (P < 0.001). Chicory root supplementation improved blood plasma prooxidative-antioxidative balance – PAB (P < 0.001) and liver PAB (P < 0.01) and thiobarbituric acid reactive substances – thiobarbituric acid-reactive substances (P < 0.05). Feeding the CR diet increased calcium (P < 0.001) and potassium (P < 0.05) and decreased cadmium (P ≥ 0.05) content in the liver when compared to the C group. Administration of the CR and IN diets increased selenium (Se) and sodium concentrations, whereas decreased zinc content both in the liver (P < 0.01; P < 0.05 and P < 0.05, respectively) and in the kidney (P < 0.01; P < 0.001 and P < 0.001, respectively) of pigs. Additionally, a higher concentration of lead (P < 0.05) was observed in the kidney of pigs fed the CR diet. In conclusion, both dietary supplements had a potential to significantly improve the Se status and oxidoreductive homeostasis in growing pigs.     

Hand-held lactate analyzer as a tool for the real-time measurement of physical fatigue before slaughter and pork quality prediction

The objectives of this study were to assess the relationship between blood lactate variation measured at the plant, and pork quality variation on a large sample size and under commercial preslaughter handling conditions. A total of 600 pigs were randomly chosen on arrival at a commercial slaughter plant and blood samples taken from the ear vein at unloading (UN), after lairage (LA), in the restrainer (RE; before stunning) and at exsanguination (EX) were analysed for lactate content using a Lactate Scout Analyzer (LSA). In order to have a large range of measures, pigs were distributed into two groups; one kept in lairage overnight (G1) and the other for 2 to 3 h (G2) before slaughter. Meat quality was assessed in the Longissimus thoracis (LT), Semimembranosus (SM) and Adductor (AD) muscles by measuring the pH 30 min postmortem (pH1) and at 24 h postmortem (pHu), the colour and the drip loss. Blood lactate levels did not differ between G1 and G2 (P>0.05). A reduced muscle lactate and glucose contents (P=0.02 and P=0.004, respectively) resulting in a lower (P<0.001) glycolytic potential (GP) was observed in the LT muscle of G1 pigs when compared with G2 loins. In the LT muscle of G1 pigs, the lower GP resulted in an increased pHu (r=−0.67; P<0.001), decreased drip loss (r=0.57; P<0.001) and darker colour (r=0.50; P<0.001) compared with G2. In both G1 and G2 pigs, the lower GP was correlated to higher pHu value in the SM and AD muscles (r=−0.73; P<0.001). The greatest correlation was observed in G2 between blood lactate levels at LA and pHu value of the SM and AD muscles (r=0.46 and r=0.44, respectively; P<0.001 for both muscles). The second greatest correlation was found between blood lactate levels at EX and pH1 value in the SM muscle in both groups (r=−0.37 and r=−0.41, respectively; P<0.001 for both groups). Based on the results of this study, it appears that blood lactate levels, as measured by the LSA, reliably reflect the physiological response of pigs to perimortem stress and may help explain the variation in pork quality.     

Influence of source and micronization of soya bean meal on growth performance,nutrient digestibility and ileal mucosal morphology of Iberian piglets

The effects of inclusion in the diet of different sources of soya bean meal (SBM) on growth performance, total tract apparent digestibility (TTAD) and apparent ileal digestibility (AID) of major dietary components and mucosal ileum morphology were studied in Iberian pigs weaned at 30 days of age. From 30 to 51 days of age (phase I), there was a control diet based on regular soya bean meal (R-SBM; 44% CP) of Argentina (ARG) origin and five extra diets in which a high-protein soya bean meal (HP-SBM; 49% CP) of the USA or ARG origin, either ground (990 μm) or micronized (60 μm), or a soya protein concentrate (SPC; 65% CP) substituted the R-SBM. From 51 to 61 days of age (phase II), all pigs were fed a common commercial diet in mash form. The following pre-planned orthogonal contrasts were conducted: (1) R-SBM v. all the other diets, (2) SPC v. all the HP-SBM diets, (3) micronized HP-SBM v. ground HP-SBM, (4) HP-SBM of ARG origin v. HP-SBM of US origin and (5) interaction between source and the degree of grinding of the HP-SBM. Dietary treatment did not affect growth performance of the pigs at any age but from 30 to 51 days of age, post weaning diarrhoea (PWD) was higher (P<0.001) and the TTAD and AID of all nutrients were lower for pigs fed the R-SBM diet than for pigs fed the HP-SBM or the SPC diets. However, no differences between the HP-SBM and the SPC containing diets were detected for any trait. The TTAD of organic matter (P=0.07) and gross energy (GE) (P=0.05) tended to be higher for the micronized HP-SBM than for the ground HP-SBM and that of GE was higher (P<0.05) for US meal than for the ARG meal. Pigs fed R-SBM had lower villus height (P<0.01) than pigs fed HP-SBM or SPC but no differences in ileal mucosal morphology were detected between SPC and HP-SBM containing diets. It is concluded that feeding the HP-SBM or SPC-reduced PWD and improved nutrient digestibility and ileal morphology as compared with feeding the R-SBM, but had no effect on pig performance. The inclusion in the diet of added value soya products (micronized SBM or SPC) in substitution of the R-SBM increased the TTAD of all nutrients and reduced PWD but had no advantage in terms of growth performance over the use of ground HP-SBM.