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The practice of weaning at 21 days of age has developed considerably in France. The objective of this trial was to study the impact of the age of piglets at weaning (at 21 or 28 days of age) on pig health after weaning under normal or degraded conditions of live. The study was performed in experimental facilities on two batches of 252 piglets from weaning until seven weeks after weaning. A feeding practice with a secure feed during the first 7 days of post-weaning was implemented for pigs weaned at 21 days. Mortality rate was recorded, and diarrhea was assessed by analyzing fecal scores and measuring the dry matter content of the feces. Blood was collected from 160 piglets (to analyze the complete blood count, haptoglobin, antioxidant defense and the production of reactive oxygen species. During the post-weaning period, 47% of piglets were observed to have diarrhea on at least one day, and this percentage was not significantly influenced by age at weaning. The piglets weaned at 21 days of age had a 7-day lag in the onset of diarrhea compared to those weaned at 28 days of age. Animals weaned at 21 days under normal conditions have a higher mortality rate than those weaned at 28 days but not under degraded conditions. These results should be confirmed by other studies.

Some plant-derived products are known for their antioxidant, anti-inflammatory or anti-bacterial properties. When provided to piglets or their dam, they may improve piglets’ ability to adapt to weaning stress. The effects of a supplementation with plant-derived products on sow and piglet physiology were investigated. Sixty-four sows were assigned to a Control or Extract group. Extract sows received 25 g/d of plant extract (Eleutherococcus senticocus, Uncaria tomentosa and Rosmarinus officinalis) in feed from day of gestation (DG) 106 to day of lactation (DL) 28 and 20 mL of essential oils (from Origanum vulgare and Eucalyptus globulus) on DG109. Within each sow group, 2 mL of essential oils (EO, from Origanum vulgare and Eucalyptus globulus) were administered to all piglets of 1 litter out of 2 at DL3. Piglets were weaned on DL28. Blood was collected from sows on DG94, DG112 and DL26 and from 2piglets/litter on DL25 and 5 d post-weaning to measure indicators of the metabolic, immune, inflammatory and oxidative status. Colostrum and milk were collected at farrowing and on DL6 and DL26. Extract supplementation had no effect on sow physiology except for fewer lymphocytes on DG112 and a lower free-fatty-acid concentration on DL26 (P < 0.05). Extract supplementation reduced fat and haptoglobin concentration in milk on DL26 (P < 0.05). On DL25, EO piglets had a lower granulocyte proportion (P < 0.05), a greater lymphocyte proportion and a lower oxidative stress index (OSI, P < 0.10), regardless of sow treatment. Piglet OSI, haptoglobin concentration and leukocytes number increased after weaning but were not influenced by sow or piglet supplementation. The present combination of plant-derived products could thus modify the composition of sow milk and the immune and inflammatory status of piglets before weaning.

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International audience; In pigs, the lean mass/fat mass ratio determines production efficiency and is strongly influenced by the number and size of cells in the tissues. During growth, the increase in the number of cells results from the recruitment of different populations of multipotent adult stem cells residing in the tissues. We hypothesized that the impact of a hygiene challenge on the proportions of adult stem cells in adipose tissue and skeletal muscle may differ between pigs with different residual feed intake (RFI), a measure of feed efficiency. At the age of 11 weeks, Large White pigs from two lines divergently selected for low and high RFI were placed in two contrasting housing hygiene conditions (good vs poor). After six weeks of challenge, pigs were slaughtered (n = 6/group). Samples of subcutaneous adipose tissue and longissimus muscle were removed, and cells from the stromal vascular fraction (SVF), which includes adult stem cells, were isolated for each tissue. Adipose and muscle cell populations from the SVF were phenotyped by flow cytometry using antibodies that targeted different cell-surface markers (CD45 to identify hematopoietic cells; CD34, CD38, CD56 and CD140a to identify cells with adipogenic and/or myogenic potential). Adipose tissue and muscle shared some common cell populations with differences in their proportions. For example, CD45-CD56+ cells were abundant in both tissues, with an average proportion of 74% in muscle and 40% in adipose tissue. Among the cell populations identified in adipose tissue, the proportion of CD45-CD56-CD34-cells were higher (P < 0.05) in pigs housed in poor hygiene than in good hygiene conditions whatever the RFI line. In skeletal muscle, preliminary analyses indicate there was an increase (P < 0.05) in the proportion of CD45+ cells in pigs of both RFI lines housed in poor hygiene conditions compared with those housed in good conditions. Other cell populations are poorly affected by hygiene of housing. This study shows that hygiene of housing conditions has an impact on some populations of adult stem cells in adipose and muscle tissue, without any difference between the two pig lines. The animal experimentation was funded by the EU FP7 PROHEALTH project (no. 613574).

International audience; Dietary methionine affects protein metabolism, lean gain and growth performance and acts in the control of oxidative stress. When supplied in large excess relative to growth requirements in diets for pigs, positive effects on pork quality traits have been recently reported. This study aimed to decipher the molecular and biochemical mechanisms affected by a dietary methionine supply above growth requirements in the loin muscle of finishing pigs. During the last 14 days before slaughter, crossbred female pigs (n = 15 pigs/diet) were fed a diet supplemented with hydroxy-methionine (Met5; 1.1% of methionine) or not (CONT, 0.22% of methionine). Blood was sampled at slaughter to assess key metabolites. At the same time, free amino acid concentrations and expression or activity levels of genes involved in protein or energy metabolism were measured in the longissimus lumborum muscle (LM). The Met5 pigs exhibited a greater activity of creatine kinase in plasma when compared with CONT pigs. The concentrations of free methionine, alpha-aminobutyric acid, anserine, 3-methyl-histidine, lysine, and proline were greater in the LM of Met5 pigs than in CONT pigs. Expression levels of genes involved in protein synthesis, protein breakdown or autophagy were only scarcely affected by the diet. Among ubiquitin ligases, MURF1, a gene known to target creatine kinase and muscle contractile proteins, and OTUD1 coding for a deubiquitinase protease, were up-regulated in the LM of Met5 pigs. A lower activity of citrate synthase, a reduced expression level of ME1 acting in lipogenesis but a higher expression of PPARD regulating energy metabolism, were also observed in the LM of Met5 pigs compared with CONT pigs. Principal component analysis revealed that expression levels of many studied genes involved in protein and energy metabolism were correlated with meat quality traits across dietary treatments, suggesting that subtle modifications in expression of those genes had cumulative effects on the regulation of processes leading to the muscle transformation into meat. In conclusion, dietary methionine supplementation beyond nutritional requirements in pigs during the last days before slaughter modified the free amino acid profile in muscle and its redox capacities, and slightly affected molecular pathways related to protein breakdown and energy metabolism. These modifications were associated with benefits on pork quality traits.

International audience; Histidine is a constituent amino acid of body proteins and, once incorporated in protein, histidine can be methylated post-translationally to methyl-histidine. Histidine is also a precursor of histamine, a neurotransmitter and involved in the immune response. Histidine and histamine are constituents of a number of dipeptides, which act as pH buffers, metal chelating agents, and anti-oxidants, especially in skeletal muscles and in the brain. A considerable fraction of whole-body histidine is present as carnosine, the dipeptide of histidine and β-alanine. In the longissimus muscle, about 40% of the total histidine content is present as carnosine. The histidine in carnosine can be methylated to anserine or balenine, and the pig is among the few species that synthesize both forms. Hydrolysis of body protein and of histidine-containing dipeptides results in the release of the constituent amino acids. However, only the histidine of protein and carnosine can be reused for protein synthesis. Methyl-histidine is either excreted in the urine or remains bound in the dipeptides and accumulates in the body. Because carnosine represents such a large histidine reservoir, a dietary histidine deficiency may not directly lead to a reduction in growth, especially if growth is given a higher priority for histidine utilization than maintaining or depleting the histidine-containing dipeptide reserves. Few histidine dose-response studies have been done in piglets and differences in the estimated requirements may be due to differences in diluting or depleting the dipeptide reserves. However, at low histidine intakes, both feed intake and growth are reduced and a reduction of the histidine-to-lysine supply by 1 percentage point results in a growth reduction of 4%. Histidine dose-response studies need to consider the role of histidine as a constituent amino acid of body protein as well as its role in dipeptides.

National audience; Background. In pigs, the ratio between lean mass and fat mass determines production efficiency and is strongly influenced by the number and size of cells in tissues. During growth, the increase in the number of cells results from the recruitment of different populations of multipotent adult stem cells residing in the tissues. We hypothesized that the impact of a hygiene challenge on the proportions of adult stem cells in adipose tissue and skeletal muscle may differ between pigs with different residual feed intake (RFI), a measure of feed efficiency. Methods. At the age of 11 weeks, Large White pigs from two lines divergently selected for low and high RFI were housed in two contrasting hygiene conditions (good vs poor). After six weeks of challenge, pigs were slaughtered (n = 5-9/group). Samples of subcutaneous adipose tissue and longissimus muscle were collected, and cells from the stromal vascular fraction (FSV), which includes adult stem cell populations, were isolated from each tissue. Adipose and muscle cell populations from the FSV were phenotyped by flow cytometry using antibodies that targeted different cell surface markers (CD45 to identify hematopoietic cells; CD34, CD38, CD56 and CD140a to identify mesenchymal stem cells (MSC) with adipogenic and/or myogenic potential).Results. Adipose tissue and muscle shared some common MSC populations although MSC diversity was higher in muscle than in adipose tissue. In muscle, the CD45- CD56+ CD34- CD140a+ and CD45- CD56+ CD34+ CD140a+ cell populations were abundant. Of these two cell populations, only the proportions of CD45- CD56+ CD34+ CD140a+ cells increased (P < 0.05) in pigs housed in poor hygiene compared with good hygiene conditions. For the CD45-CD56- CD34- cell population, present in low proportion, there was an interaction between hygiene condition and genetic line (P < 0.05) with a decrease in low RFI pigs housed in poor hygiene conditions. In adipose tissue, the two abundant MSC populations were CD45- CD56- CD34- and CD45- CD56+ CD34-. Moreover, the proportion of CD45- CD56- CD34- cells increased (P < 0.05) whereas the proportion of CD45- CD56+ CD34- tended to decrease (P < 0.1) in pigs housed in poor conditions. This study shows that the proportions of some MSC populations were affected by hygiene of housing conditions in a tissue-dependent manner in pigs of both RFI lines. Therefore, these cell populations could be targeted to modulate growth and body composition in growing animals.

International audience; The European PROHEALTH project focused on production diseases in pigs and poultry. For the pig species, INRAE has brought new knowledge to validate the role of husbandry practices in production diseases, to propose how farming conditions could be improved to preserve the health of pigs and to understand the biological mechanisms influencing the expression of these diseases. Enrichment of the housing environment of sows during gestation improved their welfare, and reduced neonatal mortality of piglets. The response over time to the stress of weaning and the prevalence of digestive problems were modulated by the feed sequence. In growing pigs, increasing the living space could be beneficial for the prevention of locomotion disorders according to the pig genetic predisposition to increase their physical activity. Also, in growing pigs, ensuring of good hygiene of housing conditions improved health and growth performance by preventing systemic inflammation and respiratory disorders. We used a model of lines divergently selected on Residual Feed Intake (RFI), a measure of feed efficiency, to show that the genetic background affected the susceptibility of pigs to diseases such as post-weaning digestive disorders, osteochondrosis and the inflammation caused by the poor hygiene of housing conditions.; Le projet européen PROHEALTH portait sur les maladies de production des porcs et des volailles. Pour l’espèce porcine, INRAE a apporté des connaissances nouvelles permettant de comprendre les mécanismes biologiques qui conduisent ou non à l’expression de ces maladies et de proposer des voies d’amélioration des conditions d’élevage pour préserver la santé des porcs. Ainsi, enrichir l’environnement des truies pendant la gestation a permis de réduire leur stress et donc d’améliorer leur bien-être et de réduire la mortalité néonatale des porcelets. Chez les porcelets, la dynamique de réponse aux stress du sevrage et la prévalence des problèmes digestifs ont été modulées par l’alimentation. Chez les porcs en croissance, augmenter la surface disponible en élevage contribuerait à prévenir l’apparition de troubles locomoteurs selon la prédisposition génétique des porcs à augmenter leur activité physique. Chez les porcs en croissance également, le respect de bonnes conditions d’hygiène du logement permet de préserver la santé et les performances de croissance en limitant l’inflammation systémique et les troubles respiratoires. En s’appuyant sur un modèle de lignées génétiques divergentes sélectionnées sur la Consommation Moyenne Journalière Résiduelle (CMJR), un indicateur de l’efficacité alimentaire, nous avons montré l’implication de facteurs génétiques dans la susceptibilité des porcs à certaines maladies comme les troubles digestifs du sevrage, l’ostéochondrose et l’inflammation causée par les mauvaises conditions d’hygiène du logement.

International audience; Impact of a hygiene challenge on adult stem-cell populations in adipose tissue of growing pigs Adipose tissue is now recognized for its secretory capacity. It helps regulate metabolism and interacts with the immune system. We hypothesized that the impact of a hygiene challenge on the proportions and properties of adult stem cells in adipose tissue may differ between pigs that differ in feed efficiency. At the age of 11 weeks, Large White pigs from two genetic lines divergent in average residual feed intake (RFI) were placed in two contrasting housing hygiene conditions (optimal vs degraded). After six weeks of challenge, pigs were slaughtered (n = 6/group). Subcutaneous adipose tissue was removed, and cells from the stromal vascular fraction (FSV), which includes adult stem-cell populations, were isolated. Differentiation of these cells was studied in vitro in the absence or presence of Tumor Necrosis Factor-α (TNF-α ), a pro-inflammatory cytokine. The ability of these cells to differentiate in the absence or presence of TNF-α did not differ among the four groups of animals (P > 0.05). Cell populations from the FSV were phenotyped by flow cytometry using antibodies that targeted different cell-surface markers (CD45 to identify hematopoietic cells; CD34, CD38, CD56 and CD140a to identify cells with adipogenic potential). While the proportions of CD45+ and CD56+ did not differ (P > 0.05) between groups, there was an interaction (P < 0.05) between genotype and hygiene conditions for the proportions of CD34+ and CD38+ cells. Overall, this study indicates that these cells were affected by poor hygiene in pig housing only in RFI-pigs.

National audience; High quality protein sources are important for both animals and humans and to limit theircompetition, animals can be fed with alternative protein sources that are not-intended forhuman consumption is needed. The acid hydrolysis of feathers (EHFM) produces a product with a very high protein digestibility but the amino acid (AA) profile is unbalanced for pigs. Although unbalanced dietary AA profile can negatively affect the overall metabolism of pigs, it can be corrected by supplementing the diet with synthetic AA. The objective of the experiment was to compare the postprandial plasma profiles of AA, glucose, free fatty acids, urea, lactate, and insulin of pigs with contrasting protein deposition (adult vs growing pigs) potential after feeding diets either unbalanced (UNB) or balanced (BAL) in AA using EHFMas a protein source. The UNB diet for both sets of pigs had low levels of certain essential AA like Lys, Met, Tyr, and His while having high levels of branched-chain AA except for Ile. Therefore, their BAL diet was supplemented with these AA to attain a more favourable AA profile for pigs. All diets were formulated to provide the same amount of total AA. Four adult and four growing pigs were fitted with a jugular catheter for serial blood collection. After an overnight fast,pigs were fed 75% of their meal allowance, then blood was collected during 6h after the meal. Each pig received each diet three times. In both stages, feeding either diet didnot affect (P > 0.05) the average concentrations of total plasma AA. Supplementation with essential AA inBAL resulted in greater (P > 0.05) average plasma concentrations of Lys, Met, Ile and His, and of Tyr in growing pigs. However, supplementation of non-essential AA to both diets resulted in lower (P < 0.05) plasma concentrations of Ala, Glu, and Gly (and Ser, which was not supplemented) in BAL compared to UNB. Lower Ser and Gly may be due to the use of these AA for Cys synthesis. The concentrations of Thr, Trp, and Val did not differ between diets (P > 0.05). With the exception of Arg, Asp, and Tyr, growing and adult pigs responded in a similar way to balancing of the diet. Average postprandial plasma concentrations of the other metabolites and insulin were unaffected (P > 0.10) by the diet. In conclusion, AA supplementation to balance a diet results in changes in plasma AA profile in growing and adult pigs. Changes in non-essential AA may be due to their roles in carbon and nitrogen metabolism.

International audience; Feeding probiotics like live Saccharomyces cerevisiae var. boulardii (SB) in swine diets is recommended to promote a better health and reduce antibiotic use during critical periods like weaning. This study was conducted to determine if SB added in the diet of sows during the last 2 months of gestation and the 4 weeks of lactation may contribute to supporting health and performance of the piglets before and after weaning. Crossbred sows (n=45) from parity one to nine were allocated to two dietary treatments, Control (n=23) and SB (n=22). Sows in the SB group were fed the same standard gestation then lactation diet as the Control sows but with the addition of SB at 1×109 cfu/kg of feed. Piglets were weaned in challenging conditions (mixing of litters, no pen cleaning). SB supplementation in sow diets influenced faecal microbiota of the sows and their piglets. Five days after weaning, the alpha-diversity was lower (P0.05) on most of health criteria measured in blood and growth performance of piglets during lactation and the post-weaning period. Moreover, dietary supplementation of SB to sows did not elicit any changes (P>0.05) on their reproductive performance, metabolic and health status, nor in the immunoglobulin and nutrient content of colostrum and milk. In the present experimental conditions, feeding SB to sows influenced sow and piglet microbiota with no consequences on health and performance.

Impact du stress oxydant sur les performances, la robustesse et la santé des animaux de rente et sur la qualité de leurs produits. Défis scientifiques Phase

International audience; Methionine (Met) is an essential amino acid (AA) in pigs and the third limiting AA in cereal based diets. Met supplementation improves animal’s performance and protein gain. Besides, Met is considered as an important factor in the control of oxidative status with potential benefits on health and meat quality. This study aimed at investigating the effects of dietary Met provided in excess relative to growth requirements on muscle metabolism in finishing pigs. During the last 14 days before slaughter, crossbred pigs were individually fed diets (13.6% protein, 5.8% fat, 10.8 MJ/kg Net energy, 0.73% Lys) supplemented (Met++) or not (CONT) with OH-Met (n=15 pigs/diet). Dietary Met content was 0.22% and 1.1% in CONT and Met++ diets, respectively. Growth rate, carcass lean meat content and Longissimus muscle (LM) weight at slaughter did not differ between the two groups. In LM, the free AA profile was modified (P

Functional roles of amino acids in improving the health of swine . International conference on green feeds and animal product safety

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Nutritional strategies for coping with health problems in pigs – A focus on amino acids. XXXIII Jornadas Téchnicas de Indukern

La croissance et la santé des porcs sont affectées par les conditions d’hygiène du logement. Le ralentissement de la croissance en conditions dégradées s’explique par la baisse d’ingestion et des modifications métaboliques induites par l’activation des fonctions de défense. Une précédente étude a rapporté des réponses moyennes contrastées en termes de performances, métabolites sanguins et indicateurs immunitaires chez des porcs soumis à un challenge sanitaire durant leur croissance. L’objectif de cette étude est de prendre en compte la variabilité interindividuelle des réponses observées afin de déterminer, par des méthodes statistiques multivariées, si un profil sanguin particulier peut prédire la variabilité de croissance. Les données ont été collectées sur 160 porcs en croissance soumis pour la moitié d’entre eux à un challenge sanitaire pendant six semaines. Les animaux ont été pesés à jeun et des prises de sang effectuées à trois reprises : avant puis trois et six semaines après le début du challenge. Le jeu de données est constitué de 51 variables comprenant des métabolites et des indicateurs des statuts redox et immunitaires sanguins. La méthode des forêts aléatoires (Random Forest) a été utilisée pour identifier 22 variables constituant de bons prédicteurs du gain de poids (GMQ). Parmi ces variables, une recherche semi-exhaustive de modèles linéaires a permis d’identifier sept variables sanguines relatives à l’inflammation, aux défenses antioxydantes et des acides aminés, permettant de prédire le GMQ avec une précision de 63% environ (R2 ajusté). Cette approche nous permet de proposer des métabolites sanguins indicateurs du ralentissement de la croissance et de mettre en exergue des modifications métaboliques en situation d’inflammation., Health and growth of pigs are affected by the hygienic conditions of housing. The lower growth rate observed in poor hygienic conditions is explained by reduced feed intake and metabolic changes caused by the activation of body defences. A previous study reported contrasting average values for growth performance, blood metabolites, redox and immune indicators in pigs subjected to a hygiene challenge during the growing period compared to pigs housed under good conditions. The objective of this study was to consider inter-individual variability in responses to determine, using a machine learning method and multivariate statistics, whether a particular blood profile can predict average daily gain (ADG). The data were collected from 160 growing pigs, half of which were subjected to a health challenge for six weeks. The animals were weighed in the fasted state, and blood samples were taken three times: before, and then three and six weeks after the beginning of the challenge. The dataset consisted of 51 variables including metabolites and immune indicators. The random forest method was used to identify 22 variables that were good predictors of ADG. Among these variables, a semi-exhaustive search of the best linear models made it possible to identify seven variables (indicators of inflammation and antioxidant status, amino acids) to predict ADG with an accuracy of about 63% (adjusted R2). This approach allows us to propose blood metabolites as indicators of slower growth and to highlight metabolic changes in a situation of inflammation.

International audience; In organic farming, piglets at weaning are often heterogeneous in age and weight, and weaning remains a critical period, despite piglets are weaned later than in the conventional system. The heterogeneity is reinforced by a poorly adapted solid diet after weaning. The aim of this pilot study was to establish profiles of piglets with different adaptive strategies at weaning based on body weight, feeding behaviour, and blood indicators. Fifty piglets were born from five sows (Landrace x Duroc) and a boar (Large White x Piétrain). On day 10 (d10), solid feed was provided ad libitum. After weaning (d42), piglets had still access to the solid feed and had access to Wrapped alfalfa roughage, both ad libitum. Piglets were allotted in five pens of 10 weaned piglets. Piglets were weighed before (d1-10-21-28) and every week after weaning (d42) up to d70. Blood was collected on d42 and d48. Behavioural observations were video-recorded the day after weaning (d43). Despite the late age at weaning, greater concentrations in haptoglobin and dROM were observed on d48 (P < 0.05). Three classes of piglets were identified according to their body weight on d42: Small [5.9-12.4 kg], Medium [12.4-13.9 kg] and Large [14.0-18.4 kg] piglets. The Small piglets spent on average more time (P = 0.006) in the feeding area and had higher (P < 0.05) haptoglobin plasma concentration compared to the Large piglets. Average weight still differed (P < 0.001) between all three categories on d70 showing that the Small piglets did not compensate their low body weight to catch up the larger piglets. Further analyses are currently ongoing for a better characterization of the adaptive profiles.

Lien vers la version preprint déposée sur Biorxiv.org https://prodinra.inra.fr/record/447811; Weaning is a critical transition phase in swine production in which piglets must cope with different stressors that may affect their health. During this period, the prophylactic use of antibiotics is still frequent to limit piglet morbidity, which raises both economic and public health concerns such as the appearance of antimicrobial-resistant microbes. With the interest of developing tools for assisting health and management decisions around weaning, it is key to provide robustness indexes that inform on the animals’ capacity to endure the challenges associated with weaning. This work aimed at developing a modelling approach for facilitating the quantification of piglet resilience to weaning. A total of 325 Large White pigs weaned at 28 days of age were monitored and further housed and fed conventionally during the post-weaning period without antibiotic administration. Body weight and diarrhoea scores were recorded before and after weaning, and blood was sampled at weaning and 1 week later for collecting haematological data. A dynamic model was constructed based on the Gompertz–Makeham law to describe live weight trajectories during the first 75 days after weaning, following the rationale that the animal response is partitioned in two time windows (a perturbation and a recovery window). Model calibration was performed for each animal. Our results show that the transition time between the two time windows, as well as the weight trajectories are characteristic for each individual. The model captured the weight dynamics of animals at different degrees of perturbation, with an average coefficient of determination of 0.99, and a concordance correlation coefficient of 0.99. The utility of the model is that it provides biologically meaningful parameters that inform on the amplitude and length of perturbation, and the rate of animal recovery. Our rationale is that the dynamics of weight inform on the capability of the animal to cope with the weaning disturbance. Indeed, there were significant correlations between model parameters and individual diarrhoea scores and haematological traits. Overall, the parameters of our model can be useful for constructing weaning robustness indexes by using exclusively the growth curves. We foresee that this modelling approach will provide a step forward in the quantitative characterisation of robustness.

The aim of this study was to evaluate the associated effects of ambient temperature and inflammation caused by repeated administration of Escherichia coli lipopolysaccharide (LPS) on insulin, energy, and AA metabolism. Twenty-eight pigs were assigned to one of the two thermal conditions: thermoneutral (24 °C) or high ambient temperature (30 °C). The experimental period lasted 17 d, which was divided into a 7-d period without LPS (days −7 to −1), and a subsequent 10-d LPS period (days 1 to 10) in which pigs were administered 5 repeated injections of LPS at 2-d intervals. Postprandial profiles of plasma insulin and nutrients were evaluated through serial blood samples taken on days −4 (P0), 4 (P1), and 8 (P2). Before the LPS-challenge (P0), postprandial concentrations of glucose, lactate, Gln, Ile, Leu, Phe, Tyr, and Val were greater in pigs kept at 24 °C than at 30 °C (P < 0.05). In contrast, Arg, Asp, Gly, His, and Met postprandial concentrations at P0 were lower at 24 °C than at 30 °C (P < 0.05). At both 24 and 30 °C conditions, pigs had greater postprandial concentrations of insulin (P < 0.01) and lower concentrations of NEFA (P < 0.01) and α-amino nitrogen (P < 0.05) at P1 and P2 than at P0. Compared with P0, postprandial concentrations of glucose were greater (P < 0.05) at P1 in pigs kept at 24 °C, and at P1 and P2 in pigs kept at 30 °C. At both ambient temperatures, pigs had lower (P < 0.05) postprandial concentrations of Ala, Gly, His, Ile, Leu, Pro, Ser, Thr, Trp, and Val at P1 and P2 than at P0. Arginine postprandial concentration at P1 was lower than at P0 in pigs kept at 24 °C (P < 0.05), whereas no difference was observed in pigs at 30 °C. Relative to P0, Gln and Tyr concentrations were lower at P1 and P2 in pigs kept at 24 °C (P < 0.01), whereas lower Gln concentration was observed only at P2 (P < 0.01) and lower Tyr only at P1 (P < 0.01) in pigs kept at 30 °C. Our study shows a hyperglycemic and hyperinsulinemic state in LPS-challenged pigs and a greater magnitude of this response in pigs kept at 30 °C. Furthermore, LPS caused important changes in BCAA, His, Thr, and Trp profiles, suggesting the role these AA in supporting the inflammatory response. Finally, our results suggest that LPS-induced effects on postprandial profiles of specific AA (Arg, Gln, Phe, and Tyr) may be modulated by ambient temperature.

International audience; This project has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement No. 613574. 2 Ghent, November 26th 2018 * WP1 : Chantziaras et al, 2018 PROHEALTH survey on 4 European countries Biocheck-Ugent™ biosecurity scoring system

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