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During early lactation cows can experience from negative energy deficit and metabolic imbalance that affect milk production and composition. At this age of precision husbandry, it is important to identify easily accessible molecules for early detection of animals suffering from extreme a negative energy balance and metabolic disorders. Milk contains a large number of molecules including metabolites and microRNA; small non-coding RNA known to regulate many biological processes, including in the mammary gland development and function. The objective of my thesis was to identify biomarkers of nutritional status and to characterize the effects of feed restriction on the mammary gland miRNome in dairy cows. Nineteen mid-lactation cows (9 Holstein and 10 Montbéliarde) were feed-restricted to 50% of their energy requirements for 6 days. The effects of this restriction on milk production and milk composition were determined. Its effects on mammary gland function was studied using nutrigenomic approaches. Milk production and blood metabolite data confirmed the energy deficit of the cows in response to the feed restriction model. The concentration of selected milk metabolites (glucose, glutamate, glucose-6P, isocitrate, β-hydroxybutyrate, uric acid and free amino acid) and fatty acids were modified by feed restriction. The study of their correlations with energy balance led us to propose glucose and glutamate as potential non-invasive biomarkers in milk. Possible differences between breeds and critical thresholds will have to be defined in a larger number of animals and during different lactation stages before these metabolites are used as on-farm indicators. 22 microRNA were differentially expressed between Holstein and Montbéliarde cows. Bioinformatic analyses highlight a potential role of these miRNAs in mammary development. The 6 most expressed miRNAs among the 22 that differentially expressed are involved in lipid synthesis. These results may partly explain the breed production differences.Feed restriction affected the expression of 27 miRNA and 374 mRNA in Holstein cows, but not in Montbéliarde. The analysis of the genomic positions of the 27 miRNAs and the literature review of the 8 most expressed miRNA reveal their role in lipid synthesis and cell proliferation. The comparison of the 374 differentially expresse mRNA with the list of potential target mRNAs of the 8 most expressed miRNA show 59 common mRNA that are mainly involved in lipid synthesis and cell development. These results suggest a role of miRNA, due to mRNA regulation, in the modulation of fatty acid profile and production during feed restriction.The short-term perspectives are to validate these results on a larger population and to study miRNA profiles in milk fat globules. In the long-term, the development of on-farm analytical methods would allow to use these indicators for the monitoring of diets and individuals.; Durant la lactation et plus particulièrement en son début les vaches peuvent subir un déficit énergétique conduisant à un déséquilibre métabolique. Ce dernier modifie la production et de la composition du lait. A l’heure de l’élevage de précision, identifier des molécules faciles d’accès pour détecter précocement les animaux en bilan énergétique négatif est un point important. Le lait est un fluide qui contient un grand nombre de molécules parmi lesquelles les métabolites et les microARN; petits ARN non-codants connus pour réguler de nombreux processus biologiques y compris dans la glande mammaire, ont été récemment détectés. L’objectif de mon travail de thèse est d’identifier des biomarqueurs du statut nutritionnel et de caractériser l’impact d’une restriction alimentaire sur le miRNome de la glande mammaire chez la vache laitière. Pour ce faire, dix-neuf vaches en milieu de lactation (9 Holstein et 10 Montbéliarde) ont été restreintes pendant 6 jours à 50% de leurs besoins énergétiques. Les effets de cette restriction sur la production et la composition fine du lait ont été déterminés. Son impact sur le fonctionnement de la glande mammaire a été étudié par des approches de nutrigénomique. Les données de production laitière et les métabolites sanguins ont confirmé le déficit énergétique des vaches. Les teneurs de certains métabolites du lait (glucose, glutamate, glucose-6P, isocitrate, β-hydroxybutyrate, acide urique et acide aminé libre) et les profils en acide gras ont été modifiés par la restriction alimentaire. L’étude de leurs corrélations avec le bilan énergétique nous ont conduits à proposer le glucose et le glutamate comme potentiels biomarqueurs non invasifs dans le lait. D’éventuelles différences entre races et des seuils critiques devront être définis sur un plus grand nombre d’animaux, et au cours de différents stades de lactation avant que ces métabolites ne soient utilisés en élevage.La comparaison des miRNomes mammaires entre les vaches Holstein et Montbéliarde a identifié 22 miARN différentiellement exprimés entre les deux races. Des analyses bioinformatiques ont mis en évidence un rôle potentiel de ces miARN dans le développement mammaire, et l’étude approfondie des 6 miARN les plus exprimés parmi les 22 a révélé leur potentiel rôle dans la synthèse lipidique. Ces deux résultats peuvent en partie expliquer les différences de production observées entre ces races.La restriction alimentaire a affecté l’expression de 27 miARN et 374 ARNm chez les vaches Holstein. Cependant aucun effet n’a été détecté sur les vaches Montbéliarde. L’analyse des positions génomiques des 27 miARN et l’analyse bibliographique des 8 miARN les plus exprimés révèlent une forte implication de ces miARN dans la synthèse lipidique et la prolifération cellulaire. L’intersection des 374 ARNm différentiels avec la liste des ARNm potentiellement cibles des 8 miARN les plus exprimés a mis en évidence 59 mARN communs majoritairement impliqués dans la synthèse lipidique et le développement cellulaire. Ces résultats suggèrent un rôle des miARN via la régulation des ARNm, dans les changements de profil d’acides gras ainsi que les pertes de production observées au cours d’une restriction alimentaire.Les perspectives de ce travail à court terme, sont de valider ces résultats sur une population plus large et d’étudier les profils en miARNs dans les globules gras du lait A plus long terme il faudra s’attacher à mettre en place des méthodes de dosages applicables en ferme afin de permettre à l’éleveur de piloter les rations et les animaux de manière précoce.

International audience; A possible driver of feed inefficiency in dairy cows is overconsumption. The objective was therefore to test precision feed restriction as a lever to improve feed efficiency of the least efficient lactating dairy cows. An initial cohort of 68 Holstein lactating cows was monitored from calving to end of ad libitum feeding at 196 ± 16 d in milk, with the last 70 d being used to estimate feed efficiency. For a given expected dry matter (DM) intake (DMI) during ad libitum feeding, offered DMI during restriction was set to observed DMI of the 10% most efficient cows during ad libitum feeding for similar performance. Feed restriction lasted during 92 d, with only the last 70 d being used for data analyses. A single diet was fed during ad libitum and restriction periods, and was based on 64.9% of corn silage and 35.1% of concentrates on a DM basis. Individual DMI, body weight, milk production, milk composition, and body condition score were recorded, as well as methane emissions. Feed efficiency was defined as the repeatable part of the random effect of cow on the intercept in a mixed model predicting DMI with net energy in milk, maintenance and body weight gain and loss within parity, feeding level, and time. Milk energy efficiency was estimated in the same way, predicting net energy in milk instead of DMI. The 15 least efficient cows ate 2.6 kg of DM/d more than the 15 most efficient cows during ad libitum feeding with 2 g/kg of DMI lower methane yield, but similar daily methane emissions. Feed restriction decreased DMI by 2.6 kg of DMI/d for the least efficient cows, which was 1.8 kg of DMI/d more than the most efficient cows, and decreased daily methane emissions by 49.2 g/d for the least efficient cows, which was 22.4 g/d more than the most efficient cows. Feed restriction had no significant effect on milk, body weight, or body weight change. Feed restriction reduced the variability of both milk energy and feed efficiencies, as shown by a decrease of their standard deviation from 0.87 to 0.69 kg of DM/d for feed efficiency and from 1.14 to 0.65 UFL/d for milk energy efficiency. Despite narrow efficiency differences, the most efficient cows during ad libitum feeding remained more efficient during feed restriction (r = 0.46 for feed efficiency and 0.49 for milk energy efficiency). The 2 efficiency groups no longer differed in feed efficiency during precision feed restriction. Precision feed restriction seemed to bring the least efficient cows closer to the most efficient cows and to reduce their methane emissions without impairing their performance.

International audience; The villages where we collected food data are located in the silvopastoral zone of Senegal (Ferlo). This vast territory located in the northern part of the country is characterized by a semi-arid climate. Development and desertification control projects have been implemented there one after the other since the drought of the 1970s and 1980s. The majority of the population is Fulani but cohabitates with Wolofs and Moors, as well as Senegalese government officials and agents of national and international NGOs. This work aims at highlighting the meaning of the cultural dietary restrictions of the fulani people living in the Senegalese Ferlo region. We document the symbolic values held by particular tools and spaces related to the cooking in a context marqued by globalization and migration. The study of culinary restraint and food prohibitions brought to the foreground a strong feeling of membership in the Fulani culture and the beginnings of a deep change within the society of Ferlo.; Les villages où nous avons recueilli des données sur les pratiques alimentaires se situent dans la zone sylvo-pastorale du Sénégal (Ferlo). Ce vaste territoire situé au nord du pays se caractérise par un climat semi-aride. Les projets de développement et de lutte contre la désertification s’y succèdent depuis les sécheresses des années 1970-80. La population est majoritairement peule, mais elle cohabite avec quelques familles wolofs et maures, ainsi qu’avec des agents de l’administration sénégalaise et d’ONG nationales et internationales. Ce travail de recherche vise à mettre enlumière le sens accordé aux interdits alimentaires et à la valeur symbolique de certains lieux et objets afférents à la cuisine des Peuls du Ferlo. L’étude de la retenue et des interdits alimentaires a fait émerger un fort sentiment d’appartenance à la culture peule, se distinguant – selon les habitants du Ferlo – par des valeurs et des normes morales contraires à l’exubérance caractéristique des autres ethnies. Notre analyse a également révélé les prémices d’un profond changement de la société du Ferlo, impactée par la globalisation et les migrations

International audience; The villages where we collected food data are located in the silvopastoral zone of Senegal (Ferlo). This vast territory located in the northern part of the country is characterized by a semi-arid climate. Development and desertification control projects have been implemented there one after the other since the drought of the 1970s and 1980s. The majority of the population is Fulani but cohabitates with Wolofs and Moors, as well as Senegalese government officials and agents of national and international NGOs. This work aims at highlighting the meaning of the cultural dietary restrictions of the fulani people living in the Senegalese Ferlo region. We document the symbolic values held by particular tools and spaces related to the cooking in a context marqued by globalization and migration. The study of culinary restraint and food prohibitions brought to the foreground a strong feeling of membership in the Fulani culture and the beginnings of a deep change within the society of Ferlo.; Les villages où nous avons recueilli des données sur les pratiques alimentaires se situent dans la zone sylvo-pastorale du Sénégal (Ferlo). Ce vaste territoire situé au nord du pays se caractérise par un climat semi-aride. Les projets de développement et de lutte contre la désertification s’y succèdent depuis les sécheresses des années 1970-80. La population est majoritairement peule, mais elle cohabite avec quelques familles wolofs et maures, ainsi qu’avec des agents de l’administration sénégalaise et d’ONG nationales et internationales. Ce travail de recherche vise à mettre enlumière le sens accordé aux interdits alimentaires et à la valeur symbolique de certains lieux et objets afférents à la cuisine des Peuls du Ferlo. L’étude de la retenue et des interdits alimentaires a fait émerger un fort sentiment d’appartenance à la culture peule, se distinguant – selon les habitants du Ferlo – par des valeurs et des normes morales contraires à l’exubérance caractéristique des autres ethnies. Notre analyse a également révélé les prémices d’un profond changement de la société du Ferlo, impactée par la globalisation et les migrations

Session : Reproduction; Impact positif d’une restriction alimentaire modérée sur les performances de reproduction de la truitearc en ciel Oncorhynchus mykiss. 6. Journées de la Recherche Filière Piscicole

Rainbow trout (Oncorhynchus mykiss) egg production is a key sector for aquaculture. This industry relies on well-controlled reproductive cycles and the extensive use of photoperiod control to obtain year-round egg production. However, feed management practices are very diverse among producers and not always designed to optimize egg production. Among these different practices, feed restriction is of major interest due to its direct impact on the reduction of egg production costs. It is however not always used under optimal conditions. The aim of the present study was to evaluate the impact of moderate feed restriction on reproductive performances and egg quality in rainbow trout. For that purpose, two feeding strategies were implemented during the last five months before the second reproduction. Females were either fed (1) ad libitum, or (2) 80% of ad libitum (i.e. restricted) with a commercial diet. An artificial photoperiod was applied to trigger reproduction during the summer. As expected, feed restriction resulted in smaller females in comparison to those fed ad libitum whereas gonado-somatic index was significantly higher in restricted females. In addition, hatching rate was significantly higher for eggs from originating from restricted females. Feed restriction led to the production of bigger eggs with less size variability and lower number of non-viable eggs. These restricted females also exhibited lower viscero-somatic index suggesting an impact of feed restriction on the allocation of reserves. However, lipid content in eggs and muscle were not different between groups, while fatty acid profile of eggs presented some differences. PUFA analysis revealed that proportions of ALA, AA and EPA were higher in eggs from restricted females, a feature possibly linked to higher egg quality. Together, these results demonstrate that feed intake of female rainbow trout broodstock can be reduced by at least 20% without any negative impact on egg production and egg quality.

International audience; In dairy cows, feed restriction is known to decrease milk yield by reducing the number of mammary epithelial cells (MEC) in the udder through a shift in the MEC proliferation-apoptosis balance, by reducing the metabolic activity of MEC, or both. The exfoliation of MEC from the mammary epithelium into milk is another process that may participate in regulating the number of MEC during feed restriction. The aim of the present study was to clarify the mechanisms that underlie the milk yield loss induced by feed restriction. Nineteen Holstein dairy cows producing 40.0 +/- 0.7 kg/d at 77 +/- 5 d in milk were divided into a control group (n = 9) and a feed-restricted group (n = 10). Ad libitum dry matter intake (DMI) was recorded during a pre-experimental period of 2 wk. For 29 d (period 1), cows were fed either 100 (control) or 80% (feedrestricted) of their ad libitum DMI measured during the pre-experimental period. Then, all cows were fed ad libitum for 35 d (period 2). Milk production and DMI were recorded daily. Blood and milk samples were collected once during the pre-experimental period; on d 5, 9, and 27 of period 1; and on d 5, 9, and 30 of period 2. Mammary epithelial cells were purified from milk using an immunomagnetic method to determine the rate of MEC exfoliation. Mammary tissue samples were collected by biopsy at the end of each period to analyze the rates of cell proliferation and apoptosis and the expression of genes involved in synthesizing constituents of milk. Feed restriction decreased milk yield by 3 kg/d but had no effect on rates of proliferation and apoptosis in the mammary tissue or on the expression of genes involved in milk synthesis. The daily MEC exfoliation rate was 65% greater in feed-restricted cows than in control cows. These effects in feed-restricted cows were associated with reduced insulin-like growth factor-1 and cortisol plasma concentrations. When all cows returned to ad libitum feeding, no significant difference on milk yield or MEC exfoliation rate was observed between feed-restricted and control cows, but refeeding increased prolactin release during milking. These results show that the exfoliation process may play a role in regulating the number of MEC in the udders of dairy cows during feed restriction without any carryover effect on their milk production.

La restriction alimentaire induit une période de perturbation de l’homéostasie de l’animal pouvant provoquer un déficit énergétique et des troubles de santé chez la vache laitière. Dans le projet casdar BioMarq’Lait, nous recherchons des biomarqueurs non invasifs (dans le lait) dans le but de fournir aux éleveurs un moyen d’identifier précocement les individus nécessitant une attention particulière, afin d’adapter leur alimentation au cas par cas, pour éviter l’apparition de troubles métaboliques et de bien-être. Le lait contient des cellules épithéliales mammaires (CEM) progressivement exfoliées de l'épithélium au cours de la lactation. Le taux d’exfoliation des CEM, correspondant au nombre de CEM exfoliées dans le lait par jour, pourrait représenter un biomarqueur indicateur de l’adaptation des vaches laitières à la restriction alimentaire. Pour tester cette hypothèse nous avons mis en place 2 essais sur vaches laitières. Dans un premier essai, dix-neuf vaches laitières Holstein à 77 ± 5 j de lactation et produisant 40 ± 0.7 kg de lait/j ont été nourries pendant 4 semaines à hauteur de 100 % (groupe témoin, n=9) ou de 80 % (groupe restreint, n=10), de leur matière sèche ingérée ad libitum pendant les deux semaines précédant le début de l’expérimentation. Du lait a été collecté après 5, 9 et 27 jours de restriction afin de purifier les CEM par une méthode d’immuno-séparation magnétique et de déterminer leur concentration. Le taux d’exfoliation des CEM a ensuite été obtenu en multipliant la concentration en CEM dans le lait par le volume de lait produit par jour. La perte de production laitière de 3,5 kg de lait par j (- 9 %) chez les vaches restreintes par rapport aux vaches témoins s’est accompagnée d’une augmentation de 65 % du taux d’exfoliation des CEM dans le lait (P

Reduction in feed intake is a common physiological response of growing pigs facing stressful environmental conditions. The present experiment aims to study (1) the effects of a short-term feed restriction and refeeding on pig performance and metabolism and (2) the differential response between two breeds, Large White (LW), which has been selected for high performance, and Creole (CR), which is adapted to tropical conditions. A trial of 36 castrated male pigs (18 LW and 18 CR) was carried out. For each breed, half of the animals were restrictively fed at 50% of the standard feed allowance for 6 days and then fed normally for the next 14 days. Growth performance, thermoregulatory responses, plasma hormones and metabolites were measured. Results showed that, for all traits, the difference in response between the two breeds was small and rarely significant, which may be due to the short duration of the feed restriction. Irrespective of breed, feed restriction induced a reduction of growth rate and feed efficiency that was rapidly compensated for upon refeeding. Feed restriction also reduced skin temperature, rectal temperature and respiratory rate, as well as blood urea and cholesterol, which are of interest as potential biomarkers for feed restriction.

Cet article discute du recours à l’alimentation en pleine conscience comme approche thérapeutique du trouble d’accès hyperphagique. Caractérisé par la consommation de grandes quantités de nourriture dans un court laps de temps, ce trouble des conduites alimentaires, le plus prévalent d’ailleurs, s’accompagne d’un sentiment de perte de contrôle sur la prise alimentaire et d’une détresse importante. Cette approche donne des résultats positifs en diminuant la fréquence des accès hyperphagiques (AH) et la quantité d’aliments consommés lors d’un AH. Elle intervient sur les trois principaux déclencheurs d’AH : la restriction alimentaire, la restriction cognitive et les envies de manger émotionnelles. La pratique quotidienne et soutenue de la méditation en pleine conscience est le plus important prédicteur des bienfaits. Elle favorise chez la personne qui la pratique la reconnaissance des signaux de la faim et de la satiété permettant ainsi de mieux réguler les apports énergétiques; elle lève les restrictions alimentaires favorisant la reconnaissance des préférences alimentaires et la satisfaction sensorielle; finalement, elle développe la conscience corporelle et l’aptitude à reconnaître les envies de manger émotionnelles qui permettra de diminuer progressivement l’alimentation émotionnelle. Puisque le champ d’exercices des diététistes-nutritionnistes n’englobe pas la modification du fonctionnement émotionnel du client ou de la cliente, une collaboration interprofessionnelle est grandement souhaitable.

Résumé; Nutritional programming in juveniles of the whiteleg shrimp (Litopenaeus vannamei) followed by a strong early feed restriction at post-larval stage. 18. ISFNF International Symposium on Fish Nutrition and Feeding "40 years of research in fish nutrition"

Résumé; Effect of food restriction on reproductive performances and egg quality in rainbow trout (Oncorhynchus mykiss). 18. ISFNF International Symposium on Fish Nutrition and Feeding "40 years of research in fish nutrition"

Effect of milking time, temperature and diet nitrogen level on milk composition of dairy cows and on some milk properties (freezing point, lipolysis and heat stability). 10. International Symposium on the Nutrition of Herbivores (ISNH)

In this study, the concept of metabolic programming has been tested for the first time in whiteleg shrimp (L. vannamei). Shrimp were raised under a 70% feed restriction during the post-larval stage over three days and compared to a control group. After 46 days, shrimp were challenged with 3 diets showing different nitrogen free-extract: crude protein ratios (1.5, 1.0 and 0.7) for 70 days. In order to test the existence of metabolic programming, we analyzed shrimp growth performance as well as mRNA levels of different metabolic and digestive actors after the stimulus, and also before and after the challenge. No direct effects of the stimulus were observed for several digestive and metabolic actors, except for the trypsin mRNA (lower in the feed-restricted group, probably linked to a decrease in dietary protein intake). As expected, significant effects associated with the diet challenge were detected for shrimp performance, i.e., growth was lower in shrimp fed with reduced levels of dietary proteins. More interestingly, some effects linked to the nutritional history were also detected showing an improved growth performance for shrimp previously restricted at the post-larvae stage. After the dietary challenge, significantly lower mRNA levels for hepatopancreatic genes involved in digestion (lipase, preamylase and trypsin), amino acid metabolism (gs), energy metabolism (cox VI b) and glucose metabolism (lvglut 1, lvglut 2 and pk) were found in restricted shrimp. The link between an enhanced growth performance and these molecular markers in early feed restricted shrimp requires further studies. Overall, our study has demonstrated for the first time that shrimp can be programmed by an early nutritional stimulus. This will allow the development of new feeding strategies in shrimp for sustainable aquaculture.

The study was conducted to investigate the effect of a quantitative feed restriction phase on the live weight of broilers and assess their compensatory growth performance. Four hundred day-old chicks (Arbor Acres) were reared in four units of 100 chicks. These units were randomized into a control group (T) fed ad libitum and three restricted groups (A, B and C). Chickens of groups A, B and C were limited to 90, 80 and 70%, respectively, of the ad libitum feed intake between 16 and 23 days of age. After the 23rd day of age, all chickens were fed ad libitum until the end of the experiment (42 days of age). Results showed that during the restriction phase the body weight and average daily gain were significantly different (p < 0.01) between the four groups, and higher in chicks fed ad libitum than in those in the restricted groups. Delayed growth was more pronounced in chicks restricted at 70% of ad libitum consumption. After returning to ad libitum feeding, compensatory growth, characterized by rapid growth, was observed just after refeeding in chicks restricted at 70%, at 35 days of age in those assigned the least severe restriction (90%), and in the last week of rearing in the group assigned an intermediate level of restriction (80%). Feed efficiency improved in the restricted groups but the final body weights remained lower than those in the group fed ad libitum. Thus, with an intermediate reduction of the amount of feed consumed (20% for eight days), a final acceptable body weight was obtained.

Effect of food restriction on reproductive performances and egg quality in the trout Oncorhynchus mykiss. 6. International Workshop on the Biology of Fish Gametes

In dairy cows, feed restriction is known to decrease milk yield by reducing the number of mammary epithelial cells (MEC) in the udder, due to an increased rate of MEC apoptosis. The exfoliation of MEC from the mammary epithelium into milk is another process that could participate in regulating MEC number. We hypothesized that the decreased number of MEC in the udder of feed-restricted cows might also result froman increase in MEC exfoliation rate. Nineteen Holstein dairy cows producing 40 ± 0.7 kg at 80 ± 4 DIM were divided into 2 groups, control (n = 9) and feed restricted (n = 10). Ad libitum DMI was recorded during a pre-experimental period of 2 wk. For 29 d (period 1), cows were fed either 100 or 80% of their DMI measured during the pre-experimental period. Then, all cows were fed ad libitum for 35 d (period 2). Feed intake andmilk production were recorded daily. Blood and milk samples were collected once during the pre-experimental period and 5, 9, and 27 d after the beginning of periods 1 and 2. Mammary epithelial cells were purified from milk samples using an immunomagnetic method. Lipid mobilization was assessed by plasma NEFA concentration. Mammary epithelium integrity was assessed by plasma lactose concentration, milk Na, andmilk Na:K ratio. Mammary tissue samples were collected by biopsy at the end of each period in order to analyze the rate of cell proliferation and apoptosis. Data were analyzed using the mixed procedure of SAS. Compared with control feeding, feed restriction induced a decrease in DMI by 20% (P < 0.001), an increase in plasma concentration of NEFA (P < 0.001), and a 3-kg/d milk yield loss (P < 0.001) but had no effect on the rate of proliferation and apoptosis in the mammary tissue. Daily MEC exfoliation rate was 65% greater in feed-restricted cows compared with control cows (P < 0.05). Feed restriction had no effect on plasma lactose concentration and milk Na:K ratio but increased milk Na concentration, which does not allow conclusions about the integrity of the mammary epithelium. In period 2, when all cows returned to ad libitum feeding, no significant difference was observed on DMI, milk yield, MEC exfoliation rate, and mammary epithelium integrity between feed-restricted and control cows. These results show that the exfoliation process could play a role in regulating the number of MEC in the udder of dairy cows during a feed restriction without a carryover effect on their milk production.

Effect of food restriction and fatty acid supplementation on metabolic parameters and plasma levels ofseveral adipokines in reproductive hens In livestock, reproductive hens are subjected to restricted diet to limit the decline of fertility associated with body mass changes. Thus, we have established an in vivo protocol of assessing the effect of different levels of restricted diet with or without polyunsaturated fatty acid supplementation (FAS) on metabolic parameters and plasma levels of adipokines (chemerin, visfatin, adiponectin) in reproductive hens. Our analysis indicates that hens fed with ad libitum diet (Ad, receiving an amount of feeding to achieve growth 1,7 times greater than the animals of the restricted diet) have a body weight, a percentage of fat, a surface of pectoral and “sot l’y laisse” muscles significantly (p, En élevage, les poules reproductrices sont soumises à une restriction alimentaire pour limiter la baisse de lafertilité, associée à des changements de masse corporelle. Ainsi, nous avons établi un protocole in vivo consistant à évaluer les effets de différents niveaux de restriction alimentaire associés ou non à une supplémentation en acide gras poly-insaturés (AGPI) sur les paramètres métaboliques et les concentrations plasmatiques des adipocytokines (chémérine, visfatine, adiponectine) chez la poule reproductrice. Nos analyses indiquent que les poules nourries avec un régime ad libitum (Ad, recevant une quantité d’aliment permettant une croissance 1,7 fois plus importante que celle des animaux du régime restreint) ont un poids corporel, un pourcentage de matière grasse, une surface de muscles pectoraux ainsi que de sot-l’y-laisse significativement (p

This article belongs to a special issueConference: 24th Annual Meeting of the Society-for-the-Study-of-Ingestive-Behavior (SSIB)Location: Porto, PORTUGALDate: JUL 12-16, 2016Sponsor(s):Soc Study Ingest BehavThe authors want to thank the adolescents who took part in the study as well as Miss Nais Petiot and Miss Audrey Marion for their help; BACKGROUND: To compare the energy and macronutrient intake responses to equivalent energy deficits induced by diet (food restriction) and exercise in adolescents with obesity. METHODS: Fourteen 12-15years old obese adolescents completed three experimental conditions (08:00am to 07:30pm) in a randomized crossover design: i) control session (CON); ii) diet-induced 25% energy depletion (Def-EI), iii) and an exercise-induced 25% energy depletion (Def-EX). The sessions order was either CON/Def-EI/Def-EX or CON/Def-EX/Def-EI as the deficit corresponded to 25% of the energy ingested at lunch on the control day (CON) and was imposed either by exercise (Def-EX) or diet (Def-EI). Ad libitum EI and macronutrients preferences were assessed at dinner and appetite sensations assessed using visual analogue scales. RESULTS: Mean BMI was 36.6+/-5.0kg/m2 (z-BMI: 2.40+/-0.29). The individually calibrated 25% energy deficit represented 254+/-92kcal. Ad libitum EI was significantly higher during both Def-EX (971+/-225kcal) and Def-EI (949+/-246kcal) compared with CON (742+/-297) (p

In broiler hens, rapid growth is often associated with a disruption of reproduction. One of the methods used byfarmers to limit the decline of fertility is feed restriction. The aim of this study is to assess the consequences ofthis type of feed intake management and polyunsaturated fatty acid supplementation (FAS) known to increaseadipokines (hormones produced by the adipose tissue) production, on fertility, steroidogenesis and eggs quantity and quality. Hence, we followed 320 hens divided into 4 equal groups fed with a restricted (Rt) or ad libitum (Ad, receiving an amount of feed to reach a 1.7 times heavier weight than the animals of the restricted diet), supplemented or not with FAS (1%). Our analyses have shown that Ad hens lay significantly (p, Chez la volaille de type chair, une croissance rapide est souvent accompagnée d’une altération de lareproduction. Une des méthodes utilisées par les éleveurs pour pallier à ces conséquences défavorables sur la fertilité est la restriction alimentaire. L’objectif de cette étude est d’évaluer les conséquences de ce typed’alimentation et d’une supplémentation en acide gras polyinsaturés (AGPI), connus pour augmenter laproduction d’adipocytokines (hormones produites par le tissu adipeux), sur la fertilité, la stéroïdogenèse et laqualité de ponte. Ainsi, nous avons suivi 320 poules réparties en 4 groupes égaux nourries avec une alimentation restreinte (Rt) ou ad libitum (Ad, recevant une quantité d’aliment permettant une croissance 1.7 fois plus importante que celle des animaux Rt), supplémentée ou non en AGPI. Nos analyses ont montré que les poules Ad pondent significativement (p

Methane generated during enteric fermentation in ruminant livestock species is a major contributor to global anthropogenic greenhouse gas emissions. A period of moderate feed restriction followed by ad libitum access to feed is widely applied in cattle management to exploit the animal’s compensatory growth potential and reduce feed costs. In the present study, we utilised microbial RNA from rumen digesta samples to assess the phylogenetic diversity of transcriptionally active methanogens from feed-restricted and non-restricted animals. To determine the contribution of different rumen methanogens to methanogenesis during dietary restriction of cattle, we conducted high-throughput mcrA cDNA amplicon sequencing on an Illumina MiSeq and analysed both the abundance and phylogenetic origin of different mcrA cDNA sequences. When compared to their unrestricted contemporaries, in feed-restricted animals, the methanogenic activity, based on mcrA transcript abundance, of Methanobrevibacter gottschalkii clade increased while the methanogenic activity of the Methanobrevibacter ruminantium clade and members of the Methanomassiliicoccaceae family decreased. This study shows that the quantity of feed consumed can evoke large effects on the composition of methanogenically active species in the rumen of cattle. These data potentially have major implications for targeted CH4 mitigation approaches such as anti-methanogen vaccines and/or tailored dietary management.

The aim of this investigation was to evaluate the effect of a 6-day food restriction period on the physiological responses and performance of 11 high-level weightlifters. After a period of weight maintenance (T2), they were assigned into two groups depending on whether they lost (Diet group, n = 6) or maintained their body weight (Control group, n = 5) during the course of those 6 days. An evaluation of performance and the measurement of salivary cortisol concentrations and salivary α-amylase (sAA) activity were performed during a simulated weightlifting competition which took place at T2, after a 6-day period of food restriction (T3). Dietary data were collected using a 6-day diet record. We noted a 41.8% decrease in mean energy intake during the dietary restriction period, leading to a 4.34% weight loss for the Diet group. Dietary restriction did not modify absolute performance levels, whilst a significant improvement was noted for the Control group. Furthermore, we noted a response of decreased...

International audience; The aims of this research is to highlight similarities and differences as well as pros and cons of face-to-face and online weight loss support communities. Thus, opinions from nutrition experts and online communities’ users are gathered. Results show that these two types of communities are similar (shared goal, mutual support, immediacy) but also different (relationship closeness, ease of expression, degree of involvement). Positive and negative effects are emphasized in a general path (support, accessibility, involvement) and then applied to eating behaviors (food diversification, restrained choices).; L'objectif de cette recherche est d'étudier les effets des communautés en ligne de soutien à la perte de poids. Les similitudes et les différences ainsi que les aspects positifs et négatifs des communautés en face-à-face et des communautés en ligne de perte de poids sont mises en évidence, grâce à des avis d'experts en nutrition et d'utilisateurs de communautés en ligne. Les résultats de cette étude montrent que ces deux types de communautés sont similaires (intérêt commun, entraide, immédiateté) mais aussi différents (proximité de la relation, facilité d'expression, degré d'implication). Les effets positifs et négatifs sont aussi mis en lumière de façon générale (soutien, accessibilité, implication) puis appliqués aux comportements alimentaires (diversification de l'alimentation, choix restrictifs).

The objective is to study the effects of nutrient restrictions, which induce a metabolic imbalance on the inflammatory response of the mammary gland in early lactation cows. The aim is to decipher the molecular mechanisms involved, by comparing a control, with a restriction group, a transcriptome and proteome, after an intra-mammary lipopolysaccharide challenge. Multi-parous cows were either allowed ad libitum intake of a lactation diet (n = 8), or a ration containing low nutrient density (n = 8; 48% barley straw and dry matter basis) for four days starting at 24 ± 3 days in milk. Three days after the initiation of their treatments, one healthy rear mammary quarter of 12 lactating cows was challenged with 50 µg of lipopolysaccharide (LPS). Transcriptomic and proteomic analyses were performed on mammary biopsies obtained 24 h after the LPS challenge, using bovine 44K microarrays, and nano-LC-MS/MS, respectively. Restriction-induced deficits in energy, led to a marked negative energy balance (41 versus 97 ± 15% of Net Energy for Lactation (NEL) requirements) and metabolic imbalance. A microarray analyses identified 25 differentially expressed genes in response to restriction, suggesting that restriction had modified mammary metabolism, specifically β-oxidation process. Proteomic analyses identified 53 differentially expressed proteins, which suggests that the modification of protein synthesis from mRNA splicing to folding. Under-nutrition influenced mammary gland expression of the genes involved in metabolism, thereby increasing β-oxidation and altering protein synthesis, which may affect the response to inflammation.

International audience

Peut-on orienter le transfert membranaire des nutriments par une limitation de l'ingestion ou un apport en fibres dans l'aliment ?

Adipose tissue is a primary sensor for nutrient availability and regulates many functions including feed intake and energy homeostasis. This study was undertaken to determine the molecular responses of adipose tissue to differences in feed intake and feed efficiency. Subcutaneous adipose tissue was collected from two lines of pigs divergently selected for residual feed intake (RFI), a measure of feed efficiency defined as the difference between actual and expected feed intake, and from a subset of high-RFI pigs that were feed-restricted at the level of the voluntary feed intake of low-RFI pigs during the growing-finishing period. Transcriptomics analyses indicated that the number of genes that were differentially expressed (P < 0.01) between low- and high-RFI pigs (n = 8 per group at each stage) in adipose tissue was much lower when pigs were considered at 19 kg (postweaning) than at 115 kg BW (market weight). Extended investigations were performed at 115 kg BW to compare low-RFI (n =8), high-RFI (n = 8), and feed-restricted high-RFI (n =8) pigs. They included in silico pathway analyses of the differentially expressed (DE) genes (P < 0.01) and a complementary proteomic investigation to list adipose proteins with a differential abundance (P < 0.10). Only 23% of the DE genes were affected by both RFI and feed restriction. This indicates that the responses of adipose tissue to RFI difference shared only some common mechanisms with feed intake modulation, notably the regulation of cell cycle (including IGF2) and transferase activity pathway. Two carboxylesterase genes (CES1, CES3) involved in lipolysis, were among the most overexpressed genes in the low-RFI pigs; they were also affected by feed restriction within the high-RFI line. About 60% of the molecular changes between low- and high-RFI pigs were specific to genetic divergence in feed efficiency, independently of feed intake. Different genes and proteins known to be associated with mitochondrial oxidative metabolism were overexpressed in adipose tissue of low-RFI pigs compared with high-RFI pigs; other proteins participating in the generation of energy were also affected by feed restriction within the high-RFI line. Finally, mitochondrial antioxidant genes were upregulated in low-RFI pigs vs. high-RFI pigs. Altogether, increased oxidative and antioxidant processes in adipose tissue might be associated with improved feed efficiency.

Des travaux récents ont porté sur les difficultés à initier et maintenir les patients dans des démarches structurées d’accompagnement de l’arrêt du tabac. Les préoccupations concernant la prise de poids au cours de cette démarche ont été particulièrement étudiées. L’arrêt est accompagné par une prise de poids et ces préoccupations sont plus fréquentes chez les femmes. Parmi ces patients, beaucoup ne sont pas prêts à faire des efforts pour cesser de fumer. Ils ont également tendance à abandonner les traitements en cours et ont moins de succès dans leur démarche. De nombreuses femmes semblent utiliser la consommation de tabac comme un comportement compensatoire, en plus de conduites alimentaires péjoratives et d’autres comportements compensatoires variés comme les régimes, les jeûnes, les vomissements et les exercices physiques. Afin de les accompagner dans les programmes d’arrêt, il est important d’aborder les difficultés liées à l’image du corps en lien avec l’estime de soi, les comportements alimentaires et la dépendance au tabac. Plusieurs domaines doivent être explorés : les caractéristiques anthropométriques, le niveau de dépendance, les comportements compensatoires, les préoccupations pondérales, le niveau de confiance dans sa capacité à contrôler son poids, les restrictions cognitives et les troubles alimentaires, le niveau de satisfaction vis-à-vis de l’image du corps, l’existence d’autres troubles psychiatriques et la motivation à l’arrêt. Différentes stratégies d’accompagnement sont intégrées à partir de programmes éprouvés dans l’obésité et les troubles alimentaires, et à partir des thérapies cognitives, de l’approche transthéorique et des entretiens motivationnels. Recent attention has been paid to the difficulty in recruiting and retaining patients in smoking cessation programs. Worry about cessation-related weight gain has received substantial attention. Smoking cessation is accompanied by weight gain, and weight gain worries are more frequent among women than men. Many of these patients are unlikely to try to quit smoking. They are also likely to drop out of treatment, less likely to quit successfully or abandon their quit attempts early. Many women seem to use smoking as a "compensatory behaviour". This concerns essentially women, who are engaged in a pattern of unhealthy nutritional practices and compensatory behaviours, including dieting, fasting, purging, and physical exercise. In order to help women in smoking cessation programs, we discuss the need to address body image disturbance itself, in association with self-esteem, eating patterns and smoking dependence. Several domains have to be measured and explored during functional analysis: anthropometrics data, level of dependence, "compensatory" behaviours, weight preoccupations, confidence in the capacity to control weight, cognitive restrictions and eating disorders, level of body-image satisfaction, psychiatric disorders, and motivation for quitting. Different strategies are incorporated from many disorder treatment programs, including the leading evidence-based for obesity and eating disorders, the cognitive therapy, the transtheoretical approach and the motivational interviewing. 19;2

Growth hormone (GH) transgenic salmon possesses markedly increased metabolic rate, appetite, and feed conversion efficiency, as well as an increased ability to compete for food resources. Thus, the ability of GH-transgenic fish to withstand periods of food deprivation as occurs in nature is potentially different than that of nontransgenic fish. However, the physiological and genetic effects of transgenic GH production over long periods of food deprivation remain largely unknown. Here, GH-transgenic coho salmon (Oncorhynchus kisutch) and nontransgenic, wild-type coho salmon were subjected to a 3- month food deprivation trial, during which time performance characteristics related to growth were measured along with proximate compositions. To examine potential genetic effects of GH-transgenesis on long-term food deprivation, a group of genes related to muscle development and liver metabolism was selected for quantitative PCR analysis. Results showed that GH-transgenic fish lose weight at an increased rate compared to wild-type even though proximate compositions remained relatively similar between the groups. A total of nine genes related to muscle physiology (cathepsin, cee, insulin-like growth factor, myostatin, murf-1, myosin, myogenin, proteasome delta, tumor necrosis factor) and five genes related to liver metabolism (carnitine palmitoyltransferase, fatty acid synthase, glucose-6-phosphatase, glucose-6-phosphate dehydrogenase, glucokinase) were shown to be differentially regulated between GH-transgenic and wild-type coho salmon over time. These genetic and physiological responses assist in identifying differences between GH-transgenic and wild-type salmon in relation to fitness effects arising from elevated growth hormone during periods of long-term food shortage

As nutritional status and inflammation are strongly connected, feeding and nutritional strategies could be effective to improve the ability of pigs to cope with disease. The aims of this study were to investigate the impact of a feed restriction on the ability of pigs to resist and be tolerant to a coinfection with Mycoplasma hyopneumoniae (Mhp) and the European H1N1 swine influenza virus, and the consequences for nutrient metabolism, with a focus on amino acids. Two groups of specific pathogen-free pigs were inoculated with Mhp and H1N1 21 days apart. One group was fed ad libitum, the other group was subjected to a two-week 40% feed restriction starting one week before H1N1 infection. The two respective mock control groups were included. Three days post-H1N1 infection, 200 g of feed was given to pigs previously fasted overnight and serial blood samples were taken over 4 hours to measure plasma nutrient concentrations. Throughout the study, clinical signs were observed and pathogens were detected in nasal swabs and lung tissues. Feed-restricted pigs presented shorter hyperthermia and a positive mean weight gain over the 3 days post-H1N1 infection whereas animals fed ad libitum lost weight. Both infection and feed restriction reduced postprandial glucose concentrations, indicating changes in glucose metabolism. Post-prandial plasma concentrations of the essential amino acids histidine, arginine and threonine were lower in co-infected pigs suggesting a greater use of those amino acids for metabolic purposes associated with the immune response. Altogether, these results indicate that modifying feeding practices could help to prepare animals to overcome an influenza infection. Connections with metabolism changes are discussed.

Dietary restriction (DR) increases healthspan and longevity in many species, including primates, but it is often accompanied by impaired reproductive function. Whether signals associated with the reproductive system contribute to or are required for DR effects on lifespan has not been established. In my doctoral thesis presented here, we show that expression of DAF-9/CYP27A1 and production of the steroid hormone ∆7-dafachronic acid (DA) are increased in C. elegans subjected to DR. DA signaling through the non-canonical nuclear hormone receptor NHR-8/NHR and the nutrient-responsive kinase let-363/mTOR is essential for DR-mediated longevity. Steroid signaling also affects germline plasticity in response to nutrient deprivation and this is required to achieve lifespan extension. Results presented in my thesis demonstrate that steroid signaling is activated by nutrient scarcity and is required for DR effects on lifespan extension through TOR signaling. In the absence of proper steroid signaling, let-363/mTOR levels remain high during starvation and the number of germ cells within the proliferative zone of the germ line is no longer affected by nutrient availability. Interestingly, genetic reduction of germ cells alleviates the requirement for steroid signaling for DR-mediated lifespan extension. Genetically lowering the germ cell count mimics the response of the germ line to DR. These data demonstrate that steroid signaling links germline physiology to lifespan when nutrients are limited, and establish a central role for let-363/mTOR in integrating signals derived from nutrients and steroid hormones. We speculate that this induces a signal that is usually emitted when nutrients are scarce and the germ line becomes less active. Taken together, this thesis work suggests that, diet-induced lifespan extension is part of a coordinated response that involves reproductive phenotypes., Une restriction alimentaire améliore la qualité du vieillissement et augmente la durée de vie chez de nombreuses espèces, y compris certains primates. Cependant, cette intervention s'accompagne souvent d'une baisse significative des capacités reproductives. Il est donc légitime de se demander si des signaux provenant du système reproductif contribuent aux effets positifs de la restriction alimentaire sur la longévité. Durant ma thèse, j'ai montré que l'expression de DAF-9/CYP27A1 et la production de l'hormone stéroïdienne D7- acide dafachronique (DA) sont augmentées chez C. elegans lorsque les vers sont soumis à une restriction alimentaire. De plus, la signalisation à l'acide dafachronique via le récepteur hormonal nucléaire NHR-8/NHR et la kinase let-363/mTOR est essentielle à l'augmentation de la durée de vie par restriction alimentaire. La signalisation stéroïde affecte également la plasticité de la lignée germinale en condition de jeûne. De plus, nous montrons que cette plasticité est nécessaire à l'augmentation de la longévité dans ce context de restriction. Les résultats présentés dans cette thèse démontrent que la signalisation des hormones stéroïdes est activée par le manque de nutriments et est requise pour l'augmentation de la longévité par la voie mTOR. En effet, chez un animal sauvage, le niveau d’expression de let-363/mTOR diminue en condition de jeûne. Ceci n’est pas observé lorsque les hormones stéroïdes sont absentes. De plus, le nombre de cellules de la lignée germinale au sein de la zone proliférative n'est plus affecté par le jeûne chez des animaux pour lesquels la synthèse d'hormones stéroïdes est inhibée. Une réduction artificielle du nombre de cellules germinales suffit à rétablir une réponse normale à la restriction alimentaire. Ceci suggère donc qu'il existe un lien étroit entre la lignée germinale et la longévité induite par une restriction alimentaire, et que ce lien repose en partie sur la signalisation des hormones stéroïdes. La kinase let-363/mTOR joue également un rôle central dans l'intégration de signaux nutritionnels et reproductifs. Nos données suggèrent également l'existence d'un signal entre lignée germinale et soma produit en condition de restriction alimentaire. L'augmentation de la durée de vie par restriction alimentaire implique donc une réponse systémique coordonnée qui implique l'appareil reproducteur.

With the reduction in antibiotic use new strategies are required in order to preserve animal health, particularly around weaning. In rabbit breading feed restriction strategies allow for the reduction of post-weaning digestive disorders and improve feed efficiency, but are inevitably responsible for a reduced growth and carcass yield at slaughter. This work aimed to optimize the growth performances and slaughter yield of restricted fed rabbits through a modulation of the dietary energy concentration and quality. The second objective of this work was to explain the physiological mechanisms underlying the beneficial effects of feed restriction upon health and feed efficiency. We demonstrated that, under a restriction strategy, a diet rich in digestible energy increased growth (+2%), slaughter yield (+0.6 points) and feed efficiency (+11%), through an improved digestive efficiency, without penalizing the sanitary parameters. The reduced growth induced by feed restriction was however only partially compensated for (-3% in final weight compared to the ad libitum fed animals). A diet rich in starch induced a higher growth and slaughter yield and did not penalize the sanitary parameters under a restriction strategy. Feed restriction and, to a lesser extent, the dietary energy concentration, modulated the immune response through a reduced humoral response at the digestive (fecal IgA) and systemic (plasmatic IgA and IgG) levels without modifying the inflammatory response. The cecal microbial activity was modulated by the amount of feed ingested while the cecal bacterial community profile, diversity and richness were not affected by the feed intake level. However, the relative abundance of certain families (Eubacteriaceae, Peptococcaceae and Christensenellaceae) and generas demonstrated specific variations according to the feed intake level and the dietary energy concentration. These results indicate that the relationship between the physiological measurements and the beneficial effects of feed restriction upon health remain complex and suggest the implication of other metabolic parameters that weren’t measured. Complementary work hypothesis must therefore be considered. This work however enabled us to establish the economic advantage of feed restriction strategies regardless of the sanitary status and demonstrated the beneficial effects of a high energy diet on growth parameters. Our study opens the door to new complementary research projects regarding the optimization of the feeding strategies through for instance the modulation of the restriction length and the dietary energy quality., Dans un contexte de limitation de l’utilisation des antibiotiques, de nouvelles stratégies doivent être mises en place pour préserver la santé des animaux, en particulier lors du sevrage. En cuniculture, les stratégies de limitation de l’ingestion permettent de réduire les troubles digestifs en post sevrage et améliorent l’efficacité alimentaire, mais induisent inévitablement un retard de croissance et une baisse du rendement à l’abattage. Ce travail de thèse avait pour objectif d’une part d’optimiser les performances de croissance et de rendement à l’abattage des animaux soumis à une restriction alimentaire via une modulation de la quantité et de la qualité énergétique des aliments et d’autre part d’expliciter les mécanismes physiologiques sous-jacents aux effets bénéfiques d'une ingestion restreinte sur la santé et l’efficacité alimentaire. Nous avons démontré que dans le cadre d’une stratégie de restriction alimentaire un aliment riche en énergie digestible permet d’optimiser la croissance (+2%), le rendement à l’abattage (+0,6 points) et l’efficacité alimentaire (+11%), via notamment une amélioration de l’efficacité digestive, sans pénaliser les paramètres sanitaires, mais ne permet de rattraper que partiellement le retard de croissance induit par la restriction alimentaire (-3% de poids à l’abattage par rapport aux animaux nourris à volonté). Un aliment riche en amidon était favorable à la croissance de ces animaux et en particulier au rendement à l'abattage et n’avait pas d’effet délétère sur les paramètres sanitaires. La restriction alimentaire et la concentration énergétique alimentaire dans une moindre mesure, modulaient la réponse immunitaire via une réduction de la réponse humorale digestive (IgA intestinaux) et systémique (IgA et IgG circulants) sans modification de la réponse inflammatoire. L’activité du microbiote caecal était quant à elle modulée par la masse d’aliment ingérée alors que le profil de la communauté bactérienne caecale, sa diversité et sa richesse ne semblaient pas modifiés par la restriction alimentaire. Toutefois l’abondance relative de certaines familles (Eubacteriaceae, Peptococcaceae et Christensenellaceae) et genres montraient des variations spécifiques à la restriction ou à la concentration énergétique de l'aliment. L'ensemble de ces résultats indiquent que les relations entre les mesures physiologiques et les effets bénéfiques de la restriction alimentaire sur la santé digestive restent complexes et suggèrent l'implication d'autres paramètres métaboliques non évalués. Des hypothèses complémentaires de travail doivent ainsi être envisagées Toutefois nos travaux établissent l’intérêt économique de la restriction alimentaire, quel que soit le contexte sanitaire, et celui de l'utilisation d'aliments à haute valeur énergétique sur les performances zootechniques. Notre étude ouvre dès lors des perspectives de recherches complémentaires d'optimisation des stratégies alimentaires via une modulation de la durée de restriction alimentaire et de la qualité énergétique des aliments.

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

International audience; European avian-like swine H1N1 was identified as one major pathogen of the porcine respiratory disease complex (PRDC) together with Mycoplasma hyopneumoniae (Mhp), and experimental pre-infection of pigs with Mhp was shown to increase the severity of a subsequent infection with H1N1. In order to evaluate novel control strategies towards such a multifactorial disease, we studied the impact of a moderate feed restriction on the ability of Mhp/H1N1 co-inoculated animals to resist the infection, as efficiency of inflammatory responses might be influenced by the nutritional status of the animal. Two groups of 8 SPF pigs were intra-tracheally inoculated with Mhp and H1N1 21 days apart. One group was fed ad libitum whereas the other one was applied a 40% feed restriction one week before H1N1 infection. Two similar mock-inoculated groups of 4 pigs each were included. All pigs were fitted with a jugular catheter. Three days post-H1N1 infection, the same amount of a standardized meal was given to all animals and kinetics of blood samples were performed during 4 hours for measuring plasma postprandial nutrient concentrations. Pigs were slaughtered 7 days post-H1N1 infection. Clinical signs were observed throughout the study and pathogens were detected in nasal swabs and lung tissues. Feed restriction had no effect on pathogen excretion and dissemination in infected host or on pulmonary lesions. However, feed- restricted pigs presented a shorter hyperthermia as well as a positive mean weight gain over the 3 first days following H1N1 infection as compared to animals fed ad libitum which lost weight during that period. Both infection and feed restriction modified postprandial kinetics of glucose and amino acid concentrations showing dramatic changes in nutrient metabolism. Our results indicated that feeding practices could be a strategy to prepare animals to overcome an influenza infection, especially in a PRDC context.