Dietary resistant starch (RS) may have prebiotic properties but its effects on fermentation and the microbial population are inconsistent. This meta-analysis aimed to quantify the relationship ...between RS type 2 (RS2) and intestinal short-chain fatty acids (SCFA) and pH as well as certain key bacterial taxa for intestinal health in pigs. From the 24 included articles with sufficient information about the animal, and dietary and physiological measurements published between 2000 and 2017, individual sub-data sets for fermentation metabolites, pH, bacterial abundances and apparent total tract digestibility were built and used to parameterize prediction models on the effect of RS2, accounting for inter- and intra-study variability. In addition, the effect of pig’s BW at the start of the experiment and duration of the experimental period on response variables were also evaluated using backward elimination analysis. Dietary RS levels ranged from 0% to 78.0% RS, with median and mean RS levels of 28.8% and 23.0%, respectively. Negative relationships could be established between dietary RS and pH in the large intestine (P<0.05), with a stronger effect in the mid and distal colon, and feces (R2=0.64 to 0.81; P<0.001). A dietary level of 15% RS would lower the pH in the proximal, mid-, distal colon and feces by 0.2, 0.6, 0.4 and 0.6 units, respectively. Increasing RS levels, however, did not affect SCFA concentrations in the hindgut, but enhanced the molar proportion of propionate in mid-colon and reduced those of acetate in mid-colon and of butyrate in mid- and distal colon (R2=0.46 to 0.52; P<0.05). Backward elimination indicated an age-related decrease in mid-colonic propionate proportion and increase in mid- and distal colonic butyrate proportion (P<0.05), thereby modulating RS2 effects. In feces, increasing RS levels promoted fecal lactobacilli (R2=0.46; P<0.01) and bifidobacteria (R2=0.57; P<0.01), whereby the slope showed the need for a minimal RS level of 10% for a 0.5 log unit-increase in their abundance. Best-fit equations further supported that a longer experimental period increased fecal lactobacilli but decreased fecal bifidobacteria (P<0.05). In conclusion, dietary RS2 seems to effectively decrease digesta pH throughout the large intestine and increase lactic acid-producing bacteria in feces of pigs which may limit the growth of opportunistic pathogens in the hindgut. To achieve these physiologically relevant changes, dietary RS should surpass 10% to 15%.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
L’amélioration de l’efficacité alimentaire est un enjeu majeur pour la compétitivité de la filière porcine. Elle est classiquement mesurée en élevage par l’indice de consommation, indicateur ...économique de l’efficacité d’utilisation des aliments pour la croissance. Un critère alternatif indépendant des performances des animaux, la Consommation Moyenne Journalière Résiduelle (CMJR), a été proposé dans les années 1960. Cet article synthétise les résultats obtenus à partir de la sélection divergente de deux lignées à l’INRA, une lignée à CMJR faible, animaux consommant moins que prédit pour leurs besoins de production et d’entretien, et donc plus efficaces, et une lignée à CMJR élevée, animaux consommant plus que prédit pour leurs besoins, moins efficaces. Ces recherches montrent qu’il est possible de sélectionner pour la CMJR chez le porc en croissance avec un impact limité sur les caractères de production et de reproduction femelle, permettant ainsi de diminuer les quantités d’aliments utilisées en élevage. La dégradation des paramètres de qualité technologique de la viande en réponse à l’amélioration génétique de l’efficacité alimentaire est un point de vigilance dans les stratégies de sélection, de même que la composition nutritionnelle de la ration alimentaire. Finalement, la capacité de réponse à des stress ou à des changements de conditions d’élevage ne semble pas affectée par la sélection, contrairement à ce qui est suggéré dans la littérature en réponse à la sélection pour une CMJR réduite. Les défis qui résultent de ces résultats pour poursuivre l’amélioration de ce caractère en production tout en répondant à l’évolution des contraintes de l’élevage sont discutés.
This review summarizes the results from the INRA (Institut National de la Recherche Agronomique) divergent selection experiment on residual feed intake (RFI) in growing Large White pigs during nine ...generations of selection. It discusses the remaining challenges and perspectives for the improvement of feed efficiency in growing pigs. The impacts on growing pigs raised under standard conditions and in alternative situations such as heat stress, inflammatory challenges or lactation have been studied. After nine generations of selection, the divergent selection for RFI led to highly significant (P<0.001) line differences for RFI (−165 g/day in the low RFI (LRFI) line compared with high RFI line) and daily feed intake (−270 g/day). Low responses were observed on growth rate (−12.8 g/day, P<0.05) and body composition (+0.9 mm backfat thickness, P=0.57; −2.64% lean meat content, P<0.001) with a marked response on feed conversion ratio (−0.32 kg feed/kg gain, P<0.001). Reduced ultimate pH and increased lightness of the meat (P<0.001) were observed in LRFI pigs with minor impact on the sensory quality of the meat. These changes in meat quality were associated with changes of the muscular energy metabolism. Reduced maintenance energy requirements (−10% after five generations of selection) and activity (−21% of time standing after six generations of selection) of LRFI pigs greatly contributed to the gain in energy efficiency. However, the impact of selection for RFI on the protein metabolism of the pig remains unclear. Digestibility of energy and nutrients was not affected by selection, neither for pigs fed conventional diets nor for pigs fed high-fibre diets. A significant improvement of digestive efficiency could likely be achieved by selecting pigs on fibre diets. No convincing genetic or blood biomarker has been identified for explaining the differences in RFI, suggesting that pigs have various ways to achieve an efficient use of feed. No deleterious impact of the selection on the sow reproduction performance was observed. The resource allocation theory states that low RFI may reduce the ability to cope with stressors, via the reduction of a buffer compartment dedicated to responses to stress. None of the experiments focussed on the response of pigs to stress or challenges could confirm this theory. Understanding the relationships between RFI and responses to stress and energy demanding processes, as such immunity and lactation, remains a major challenge for a better understanding of the underlying biological mechanisms of the trait and to reconcile the experimental results with the resource allocation theory.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•Non-castration of males and organic farming contribute to the societal image of pork.•Feeding strategy is a way to improve many quality dimensions of organic pork.•Feeding improves technological ...quality without impairing the growth of organic pigs.•Linseed, camelina meal and roughage improve the fatty acid n-3 and n-6 profile of pork.•Modulating quality dimensions concerns many stakeholders along the pork chain value.
Since 2022, European specifications for organic pig farming have evolved to distribute 100 % organic feed and to reinforce the link to the soil with feed resources that should primarily be obtained from the farm or the same region. Feeding strategy acts as a lever to improve various quality dimensions of organic (as well as conventional) pork, including intrinsic dimensions (carcass composition, nutritional, organoleptic, technological, sanitary qualities) and extrinsic dimensions related to animal farming (image). Diet may also influence the risk of undesirable odours or flavours that may be found in pork from non-castrated male pigs. This study aimed at evaluating the effects of a specific feeding strategy on several quality dimensions of organic meat from non-castrated male pigs. The experiment was conducted with 77 organic non-castrated male pigs (Piétrain NN × Large White) reared according to organic specifications and distributed in two batches. Within litters, male littermates were allocated at around 33 kg of live weight to either a Control group which received a Control feed (C) corresponding to the organic specifications or in a Bio+ group which received an organic test feed based mainly on French raw materials and which contained more fibres (faba bean and access to forages) and omega-3 fatty acids (linseed, camelina). All pigs were reared in the same building on deep straw bedding (1.3 m2/pig) with free outdoor access (1.0 m2/pig) using one pen per experimental group. Pigs were fed ad libitum until slaughter at about 125 kg live weight. Average daily gain, carcass weight and lean meat content did not differ significantly between C and Bio+ pigs. Compared to C, Bio+ pigs had higher (P < 0.05) ultimate pH in the loin (Longissimus muscle) and ham (Gluteus medius, and Semimembranosus) muscles, associated with a lower Longissimus muscle glycolytic potential (P < 0.001). Loin and ham meat from Bio+ vs. C pigs was lighter (P < 0.05) and had a more intense red colour (P < 0.10). The Bio+ strategy led to a lower Longissimus muscle n-6:n-3 fatty acid ratio (P < 0.001), indicating an improvement in pork nutritional value. Backfat skatole concentration was lower in Bio+ than in C pigs whereas backfat androstenone was higher in Bio+ than in C pigs (P < 0.05). Altogether, we demonstrated that the Bio+ strategy had positive impacts on several qualities of organic pork from non-castrated male pigs.
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•Iodine-containing phosphate-based glasses are compared in terms of durability.•Phosho-molybdate glasses are more durable than phosphate glasses in pure water.•Nb2O5 improves the chemical durability ...of phospho-molybdate glasses.•Acidic conditions seem detrimental to the durability of these conditioning matrices.
Silver phosphate glasses have been investigated for the conditioning of radioactive iodine 129. Their disposal in a deep geological repository requires high chemical durability, and to improve this property, two crosslinking agents were examined here: Nb2O5 and Bi2O3. In addition, for some of these glasses, 50 % of phosphorus was replaced by molybdenum to assess the role of glass former entities. The effect of these modifications on the glass chemical durability was studied in pure water, at 50°C. Given the very long half-life of iodine 129 (15.7 × 106 years), only long-term alteration tests were carried out, in order to check if a passivating alteration layer could be formed in these conditions. Alteration rates were then calculated following various methods and compared. Results showed that the use of elemental releases in solution alone leads to an underestimation of the alteration rate, as there is no tracer element in the glass composition. For phospho-molybdate glasses, the addition of Nb2O5 had a significant effect on their chemical durability, i.e. their ability to form a passivating layer that retains most of the elements that are part of the pristine glass. For phosphorus, the more mobile element, release rates decreased by two orders of magnitude compared to phosphate-only glasses, and this trend depends on the Nb2O5 concentration.
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Iodine 129 is a radioactive waste produced by the nuclear industry. Due to its high volatility, it cannot be vitrified in conventional borosilicate glasses. This paper investigates the feasibility of ...iodine conditioning using a glass matrix intended for long-term storage in a geological repository. Silver phosphate glasses, which can incorporate high amounts of iodine and can be synthesized at low temperature, were chosen for this study. In order to increase their chemical durability, the glasses were cross-linked by niobium and bismuth oxides. Niobium and bismuth incorporation limits were determined for an iodine amount of 12 wt% and ranged from 1.6 mol% to 4.0 mol%, depending on the Ag2O/P2O5 ratio. The glass structures were investigated using 31P MAS NMR, RAMAN spectroscopy and X-ray absorption spectroscopy. The iodine local environment was determined by EXAFS at iodine K-edge. Structural investigations showed that the introduction of these crosslinking reagents induces a significant increase in the polymerization degree of the glasses. However despite this higher connectivity, the two crosslinking reagents have a low impact on the glass transition temperature after iodine addition.
•Nb2O5 and Bi2O3 display a higher solubility in silver phosphate glasses than Al2O3.•Their solubility depends on the Ag/P molar ratio in iodine –containing glasses.•A higher solubility is linked to a higher polarizability.•Addition of the crosslinking reagents increases the polymerization degree.•Tg is less affected by crosslinking reagents in the presence of iodine.
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Sanitary challenges negatively affect feed intake and growth, leading to a negative impact on animal well-being and economic losses. The aim of this study was to carry out a meta-analysis to quantify ...the dynamic feed intake and growth responses of growing pigs after a sanitary challenge. A database was constructed using 122 published experiments reporting the average daily feed intake (ADFI) and the average daily gain (ADG) of pigs subjected to one of six sanitary challenges: digestive bacterial infections, poor housing conditions, lipopolysaccharide (LPS) challenges, mycotoxicoses, parasitic infections and respiratory diseases. The responses to experimental challenges were calculated relative to that of a control group. Statistical analyses were carried out for each challenge to quantify the mean and the dynamic responses in feed intake and growth and to identify the basis of the reduction in growth (i.e. reduction in feed intake or reduction in feed efficiency related to changes in maintenance requirements). All challenges resulted in a reduction in ADFI and ADG, with the strongest responses for mycotoxicoses, respiratory diseases and digestive bacterial infections (8% to 23% reduction in ADFI and 16% to 29% reduction in ADG). The reduction in ADG was linearly related to the reduction in ADFI for digestive bacterial infections, LPS challenge, parasitic infections and respiratory diseases. For poor housing conditions and mycotoxicoses, the relationship was curvilinear. A 10% reduction in ADFI resulted in a reduction in ADG varying from 10% for mycotoxicoses to 43% for digestive bacterial infections. More than 70% of the reduction in ADG could be explained by the reduction in ADFI for mycotoxicoses, LPS challenge and respiratory diseases. For challenges associated with the gastrointestinal tract, a large part of the reduction in ADG was due to an increase in maintenance requirements, suggesting digestive and metabolic changes. A dynamic pattern in the reduction in feed intake and growth rate could be identified for digestive bacterial infections, mycotoxicoses and respiratory diseases. For digestive bacterial infections and mycotoxicoses, pigs did not fully recover from the challenge during the experimental period. The results of this study can be used to quantify the effects of a sanitary challenge in growth models of pigs.
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Introduction Le diabète MODY (Maturity-Onset Diabetes of the Young) est une forme monogénique autosomale-dominante de diabète non auto-immun diagnostiqué avant 25 ans. Le MODY est caractérisé par un ...déficit primaire de la sécrétion d’insuline. Ses causes génétiques sont hétérogènes et ∼30 % des cas restent non-élucidés (MODY-X). Nous avons utilisé le séquençage de l’exome entier (SEE) dans une large famille MODY-X pour identifier une nouvelle étiologie du MODY. Matériels et méthodes Un SEE a été réalisé chez quatre membres d’une famille MODY-X incluant le cas index (diabétique à 17 ans), son père diabétique (diagnostiqué à 20 ans), sa mère non-diabétique et son cousin germain diabétique (diagnostiqué à 13 ans). Après capture des exons (Agilent SureSelect-50 Mb), les librairies exomiques ont été séquencées en utilisant deux lignes du séquenceur GAIIx (Illumina) avec une couverture moyenne d’au moins 100×. Les mutations potentiellement causales ont été testées dans la famille (au total, 8 diabétiques et 18 non-diabétiques sur quatre générations) et chez 406 contrôles normoglycémiques, par une puce à ADN (BeadXpress-Illumina). Résultats Après le SEE du quartet et l’identification des variants génétiques (∼50 000 par individu), nous avons éliminé les variants présents dans la base publique dbSNP130 et chez la mère non-diabétique, et avons ciblé les variants co-ségrégeant avec le diabète au sein du quartet. Les 153 mutations restantes ont été testées dans la famille étendue et chez 406 contrôles. Une seule mutation non synonyme co-ségrégeait avec le diabète et n’était pas présente chez les contrôles : la mutation p. E227K du gène KCNJ11, déjà référencée chez des patients avec diabète néonatal transitoire. Conclusion En l’absence de diabète néonatal dans la famille (diagnostic > 13 ans), ce résultat élargit le spectre des phénotypes associés aux mutations du canal potassique ATP-dépendant, et suggère que le séquençage du gène KCNJ11 doit être proposé en routine dans l’exploration des formes familiales de DT2 à début précoce.
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Feed restriction could be a relevant strategy to preserve gut health, reduce systemic inflammatory response and finally limit antibiotic use. This study assessed the effect of feed restriction on ...growing pigs submitted to a moderate inflammatory challenge induced by the degradation of the environmental hygiene that is known to alter growth rate. The experiment was run on 80 pigs selected at 7 weeks of age according to a 2×2 factorial design: two feeding levels, ad libitum (AL) and feed restricted (FR) at 60% of AL, and two conditions of environmental hygiene, clean and dirty. Pigs were housed individually throughout the experiment. From 61 to 68 days of age (day 0 to 7), pigs were housed in a post weaning unit and feed restriction was applied to half of the pigs from day 0 to day 29. At 68 days of age (day 7 of the experiment), pigs were transferred in a growing unit where half of FR and half of AL pigs were housed in a dirty environment (poor hygiene) and the other half in a clean environment (good hygiene) until day 42. Growth performance was recorded weekly. Blood and faeces samples were collected to measure indicators of inflammation, nutrient digestibility and microbiota composition. Faecal consistency was monitored daily to detect diarrhoeas. Feed restriction decreased daily weight gain (−35% to −50%, P<0.001), increased the feed conversion ratio (+15%, P<0.001) and CP digestibility (+3%, P<0.05) and reduced the occurrence of diarrhoeas irrespective of hygiene conditions. Poor hygiene conditions decreased growth performance (−20%, P<0.05) and total tract digestibility of all nutrients (P<0.001). Haptoglobin (+50%) concentrations and lymphocyte (+10%) and granulocyte (+40%) numbers were higher in poor hygiene conditions (P<0.05), confirming that the model was effective to induce a systemic inflammatory response. Both feed restriction and hygiene modified the profile of the faecal microbiota. In this study, feed restriction did not reduce the systemic inflammatory response caused by poor hygiene conditions despite the limitation of the occurrence of digestive disorders. However, our study opens discussions regarding the impact of hygiene and feed restriction on gut microbial communities and digestive health.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Feed intake and its daily pattern are regulated both at a short and a long term by several control pathways, including energy balance regulation. This trial aimed to determine the effect of dietary ...fibre (DB) (mix of wheat, soy and sugar beet pulp fibres) and aleurone supplementation and their interaction on energy and nitrogen balances in growing pigs with ad libitum access to feed. Forty pigs (BW: 35 kg) were fed diets differing by fibre concentration (NDF concentration: 10% or 14% DM) and aleurone supplementation (0, 2 or 4 g/kg) during 3 weeks. Pigs were housed individually in a respiration chamber during the last week to record feeding behaviour and measure energy and nitrogen balances (n = 36). Glucose oxidation was studied on the 6th day with an injection of U-13C glucose and measurement of 13CO2 production. There was no significant interaction between DB inclusion and aleurone supplementation on any variables characterizing feeding behaviour. Pigs had less but longer meals with high level of DB, with an increased interval between two meals without effect on daily feed intake. The meal frequency significantly decreased when aleurone supplementation increased. Total tract apparent digestibility coefficient of DM, organic matter, ash, nitrogen and gross energy decreased when pigs received high DB level. Dietary fibre level increased significantly faecal excreted nitrogen. Aleurone supplementation decreased nitrogen retention. Free access to the feed induced a great individual variability not only in feed intake level (from 784 to 2290 g/day) but also in feeding behaviour (from 5.5 to 21.5 meals per day). This variability can be linked with the importance of underlying feed intake regulation pathways and difference in energy balance and metabolism efficiency. Several profiles of metabolism efficiency can be discriminate, thanks to a clustering based on feeding behaviour and pre-prandial concentrations of metabolites and hormones. In conclusion, DB inclusion decreased meal frequency, increased average meal size, decreased total tract apparent faecal digestibility coefficient of nitrogen and gross energy. Supplementation of aleurone decreased average daily feed intake with a reduction of the meal number per day, without modification of average meal size. Aleurone supplementation decreased nitrogen retention and nutrient deposition. Independently of experimental diets, the high individual variability permitted discriminating different profiles with different metabolic strategies. Efficient pigs with a high energy retention as protein and lipid seem to be able to adapt their metabolism according to energy sources.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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