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National audience; Pendant l'allaitement la lapine émet des fèces dures dans le nid, qui sont en partie ingérées par les lapereaux. L'objectif de notre étude est i) d'évaluer l'effet de l’ingestion de fèces maternelles au nid sur l'implantation du microbiote cæcal par séquençage 454 de la région V3-V4 des gènes codant pour l’ARN 16S, la croissance et la survie des lapereaux et ii) d’orienter le processus d'implantation du microbiote en substituant les fèces aternelles par des fèces issues d’autres femelles sous antibiothérapie ou non. Dans le lot témoin, les fèces maternelles sont dénombrées et laissées à disposition des lapereaux dans le nid (lot T, n=24 portées), dans le lot R (n=28 portées) les fèces sont comptées puis retirées. Dans les deux derniers lots les fèces maternelles sont comptées, retirées et remplacées par des fèces issues de femelles étrangères non traitées (E, n=28 portées) ou traitées aux antibiotiques (Eab, n=29 portées). L’apport de fèces de lapines étrangères multiplie par 3 le comportement de coprophagie du lapereau (p

Chantier qualité GA; National audience; The meat of overfed ducks and geese is quite different from that of waterfowl fed ad libitum, particularly because of its higher lipid content (2-fold more) affecting the nutritional and sensorial quality of products and their storage ability. However, these characteristics can be quite variable according to the technical conditions used during rearing and overfeeding periods such as the composition and distribution modalities of diets, age at the beginning of the overfeeding period and duration of overfeeding. The pre-slaughter conditions and the slaughtering and processing technologies are also important. The genetic parameters of carcass and meat quality traits have been mainly evaluated for ducks. Meat quality traits are weakly heritable. Recently, few QTL have been highlighted particularly for cooking loss, pH and meat texture. The knowledge of the genes involved in the control of these parameters should in the short or long term allow including them in selection programmes.; La viande de palmipèdes gavés se distingue de la viande de palmipèdes non gavés surtout par son enrichissement en lipides (teneur multipliée par deux) qui modifie la qualité nutritionnelle et sensorielle des produits et leur aptitude à la conservation. Toutefois, ces caractéristiques peuvent fortement varier selon l’itinéraire technique mis en oeuvre pendant les phases d’élevage et de gavage et en particulier en fonction de la composition et des modalités de distribution de l’aliment, de l’âge à la mise en gavage et de sa durée. Les étapes de pré-abattage et la technologie d’abattage et de transformation sont également importantes à considérer. Les paramètres génétiques de la qualité de la carcasse et de la viande ont surtout été étudiés chez le canard. Ces critères de qualité sont dans l’ensemble faiblement héritables. Récemment, plusieurs QTL ont été mis en évidence en particulier pour les pertes à la cuisson, le pH et la texture de la viande. La connaissance des gènes impliqués dans le contrôle de ces paramètres devrait permettre à plus ou moins long terme de les inclure dans les schémas de sélection.

International audience; The fattening performances, nitrogen excretion and health status of growing rabbits were studied in response to a linear reduction of the digestible fibre (DgF = water-insoluble pectins + hemicelluloses) to crude protein ratio (DFP) in four diets (from 1.01 to 1.55). As the crude protein level was reduced from 17.7% to 13.9% (in diets DFP1 DFP4), the DgF level was increased from 18.5% to 22.1%, without changes to poorly-digestible fibre levels (ADF = 19%). A total of 644 rabbits per diet were used in a multi-site study (n = 6). Between weaning (28d-37d according to sites) and 49d of age, reduction of the DFP ratio led to a linear decrease in weight gain (-4 g/d between DFP1 and DFP4, P 20%) reduced the mortality by diarrhoea for the two highest DFP ratios when compared to the two lowest ratios (5.2% vs. 7.8%, P

Caecal microbial activity and blood metabolic profiles were assessed according to the health status (diarrhoeic vs. healthy) in growing rabbits after induction of a nutritional enteropathy. Rabbits were fed ad libitum from weaning (28 days) to 70 days of age with a standard fibre content diet (n= 150) or with a deficient fibre diet (n = 209) known to induce non specific enteropathy. The reduction of fibre intake caused a significantly delayed weight growth and markedly increased the health risk index (mortality + morbidity). In diarrhoeic rabbits, dry matter and total volatile fatty acid (tVFAs) concentrations in the caecum dramatically decreased by 27 and 40%, respectively whereas the caecal ammonia concentration, minor VFA proportions and pH markedly increased by 2 and 8.5 times and by 0.7 unit, respectively. In parallel, the C3:C4 ratio increased fourfold and the pectinase activity was significantly depressed. Blood plasma glucose, potassium and albumin concentrations significantly decreased in diseased animals compared to the healthy ones while urea and total cholesterol concentrations showed a two-fold increase suggesting preferential metabolical utilisation of lipids and proteins. These results show that the caecal function and blood metabolic profiles were greatly affected during nutritionally induced enteropathy and that the observed changes were globally similar to those induced by coccidiosis or colibacillos

Après une présentation des principes de l’alimentation, seule la conduite de l’alimentation en élevage rationnel est étudiée

Chantier qualité GA; International audience; We investigated liver protease activity in force-fed and non-force-fed ducks using zymography gels to better understand mechanisms underlying liver steatosis in palmipeds. Male Muscovy and Pekin ducks were slaughtered before and after a short period (13 d) while they were conventionally fed or force fed. The force-fed regimen contained a high level of carbohydrates and was delivered in large doses. Main hepatic proteases (matrix metalloprotease-2, calpains, and cathepsins) were extracted from raw liver and specifically activated within electrophoretic gels. Both force-fed Muscovy and Pekin ducks presented higher liver weights and BW associated with lower matrix metalloprotease-2 and m-calpain hepatic activities. On the other hand, hepatic cathepsin activity was not affected by force feeding. It was concluded that Muscovy and Pekin duck hepatic proteases are affected similarly by the force feeding. Thus, this cannot explain differences observed between Muscovy and Pekin ducks regarding their ability to develop hepatic steatosis generally reported in literature.

L’objectif de cette étude est, d’une part, d’estimer les impacts environnementaux d’un système représentatif des pratiques de production nationale de lapin de chair, et d’autre part, d’évaluer les conséquences d’une restriction alimentaire pratiquée chez le lapin après le sevrage à l’aide de la méthode d’Analyse du Cycle de Vie. La restriction de l’ingestion entraîne une baisse du potentiel de réchauffement climatique (- 9 %), des potentiels d’eutrophisation (- 11 %) et d’acidification (- 12 %) et de l’occupation des surfaces agricoles (- 10 %). Elle montre également que l’alimentation des animaux et les effluents sont les postes qui contribuent le plus aux différents impacts environnementaux. L’étape d’engraissement contribue également plus que les étapes de maternité ou d’abattage. Ces résultats offrent des perspectives de travail pour proposer des stratégies possibles d’amélioration.

International audience; The aim of this trial was to study the influence of loose-mix feeding on behavior, feed intake, and BW of growing geese. In total, 252 one-day-old geese (Anser anser) were divided into 2 groups differing in the form of diet they received between 42 and 98 d of age (AME(n) 11.55 MJ/kg, CP 16%): a complete pelleted diet containing 500 g of sorghum/kg (control group) or a mixture containing 500 g of protein-rich pellets and 500 g of sorghum whole seeds/kg (mixed group). Feed intake was measured daily from 42 to 48 d and every 3 d from 49 to 98 d. Individual BW was measured weekly from 42 to 98 d. Goose behavior was monitored by the scan sampling method throughout the experiment, which was divided into 5 periods according to the timing of access to feed: period 1 from 42 to 55 d (ad libitum feeding access), period 2 from 56 to 62 d (2 + 2 h feeding access), period 3 from 63 to 70 d (2 h feeding access), period 4 from 71 to 94 d (1 h feeding access), and period 5 from 95 to 97 d (3 h feeding access). Over the whole period, the feed intake (13,968 and 14,480 g) and the feed conversion ratio (8.53 and 8.15) were similar in both groups (P = 0.112 and P = 0.168; respectively). Body weight was similar in both groups from 42 to 91 d of age, but at 98 d of age, BW was 3.7% lower in the control than in the mixed group (P = 0.006). Goose behavior was influenced by period, because the percentage of birds feeding increased when the daily access time to the feed decreased (P < 0.001), but not by group (P > 0.05). The results suggest that a loose-mix feeding could be recommended in feeding of growing geese because it weakly influences their feed behavior but slightly increases their weight at the end of the growing period.

Chantier qualité GA; International audience; To provide a comprehensive examination of the bacterial diversity in the rumen content of cows fed different diets, high-throughput 16S rRNA gene-based pyrosequencing was used. Four rumen fistulated nonlactating Holstein cows received 12 kg of dry matter per day of four diets based on maize silage during four periods: the low-starch diet (22% starch, 3% fat); the high-starch diet, supplemented with wheat plus barley (35% starch, 3% fat); the low-starch plus oil diet, supplemented with 5% of sunflower oil (20% starch, 7.6% fat) and the high-starch plus oil diet (33% starch, 7.3% fat). Samples were taken after 12 days of adaptation, 5 h postfeeding. Whatever the diet, bacterial community of sieved rumen contents was dominated by Firmicutes and Bacteroidetes. Lachnospiraceae, Ruminococcaceae, Prevotellaceae, and Rikenellaceae families were highly present and were clearly affected by cow diet. The highest abundance of Prevotellaceae and the lowest abundance of Ruminococcaceae and Rikenellaceae were found with the high-starch plus oil diet. Dietary starch increased the relative abundance of only three genera: Barnesiella, Oribacterium and Olsenella, but decreased the relative abundances of several genera, with very significant effects for Rikenellaceae_RC9 and Butyrivibrio-Pseudobutyrivibrio. Oil alone had a limited effect, but interestingly, starch plus oil addition differently affected the bacterial populations compared to starch addition without oil.

National audience; L'efficacité alimentaire est un indicateur essentiel pour juger de la performance et de la rentabilité d'un système d'élevage. En cuniculture, l'indice de consommation technique (maternité+engraissement) est passé de 3,8 à 3,4 durant les 15 dernières années. Ainsi, les rejets azotés et phosphorés ont été réduits d'environ 10%. Cette amélioration provient des progrès conjoints sur : la maîtrise sanitaire, les techniques d'alimentation (notamment le rationnement), la maîtrise du logement (ventilation, température, etc.) et le potentiel génétique. Cette synthèse résume l'impact de ces différents paramètres sur l'efficacité alimentaire. A l'avenir, il semble possible d'améliorer encore l'efficacité alimentaire, et donc de réduire à la fois les intrants et les rejets, pour atteindre un indice de consommation technique d'environ 3,0, comparable à celui enregistré en système porcin.

International audience; Trans fatty acids (FA), exhibit different biological properties. Among them, cis-9,trans-11 conjugated linoleic acid has some interesting putative health properties, whereas trans-10,cis-12 conjugated linoleic acid has negative effects on cow milk fat production and would negatively affect human health. In high-yielding dairy cows, a shift from trans-11 to trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. To study this shift, 4 rumen-fistulated nonlactating Holstein cows were assigned to a 4 x 4 Latin square design with 4 different diets during 4 periods. Cows received 12 kg of dry matter per day of 4 diets based on corn silage during 4 successive periods: a control diet (22% starch

National audience; The aim of our study was to elaborate a new biotechnical breeding system of mule ducks improving its sustainability. Four flocks of 2400 mule ducks were successively raised on classical grass free ranges (n=2) or with trees (n=2) between 4 and 12 weeks. Half of the ranges (one of each type) have been divided in two parts to allow rotation at 8 weeks. The instantaneous stocking density of ducks under rotation was twice (3 m 2 per duck instead of 6). The presence of trees can favour growth and live body weight at 12 weeks, being improved two fold over four. By contrast rotation can lead to lower growth performances, but these deleterious effects disappear after two weeks force feeding and thus, liver and breast muscle production are finally not affected. With rotation, ducks appear often more dirty and with less feathering. Presence of trees can enhance the dirtiness of ducks, but they improve the quality of feathering. During sunny days and hot temperatures ducks appreciate to stay in the shadow under the trees. However it does not improve their distribution in the range as far they keep close to the drinkers. Tree growth also seems to be influenced with their distribution in the range. When harvesting grass, the longer time without duck on half of the range in case of rotation can allow bringing off a larger amount of biomass. The soil analysis shows an increasing of organic matter due to leaves in presence of trees. The presence of trees seems comfortable for birds, it improve the visual aspect of the free ranges, and subsequently will produce valuable biomass.

Cet article présente le déroulement d’une démarche d’éco-conception pour proposer des innovations permettant de réduire les impacts environnementaux de la production de foie gras d’oie. Une Analyse de Cycle de Vie portant sur l’itinéraire standard de production du foie gras d’oie français a permis de montrer que l’alimentation explique la majeure partie des impacts environnementaux de ce produit (plus de 50% en moyenne) et qu’elle représente donc le levier d’action le plus pertinent. Plusieurs expérimentations ont été réalisées afin d’évaluer les possibilités d’utilisation du sorgho, la réponse du système biologique par rapport à l’utilisation du maïs, et les conséquences sur la durabilité environnementale à l’échelle du cycle de vie du produit jusqu’à la sortie de l’abattoir et sur la durabilité économique et sociale à l’échelle de l’exploitation, d’une substitution du maïs par du sorgho dans la ration alimentaire des oies. Les travaux montrent qu’une substitution totale du maïs par du sorgho dans la ration alimentaire est techniquement possible. Elle réduit la plupart des impacts environnementaux de la fabrication d’1 kg de foie gras (potentiel de réchauffement climatique : - 18%, potentiel d’acidification : -12%, utilisation d’énergie primaire : - 23%, utilisation de la ressource en eau : - 62%) et améliore de nombreux indicateurs de performances de durabilité économique, tel que l’indice de consommation (- 9,4%) ou le poids de foie (+ 13%). Cependant certains indicateurs économiques et sociaux sont dégradés, tels que l’intention de consommer à nouveau le produit (- 17 pts) en raison d’un foie de couleur plus pâle, et l’augmentation de la mortalité en gavage (+ 4,6 pts). L’ensemble des résultats suggère que l'utilisation du sorgho dans l’alimentation des oies peut améliorer la durabilité de la production de foie gras. Plusieurs ajustements dans l’itinéraire de production sont nécessaires pour optimiser l’utilisation de cette matière première., We present the results of an eco-design approach to offer innovations that reduce the environmental impacts of the production of foie gras. A Life Cycle Assessment was carried out on the standard French foie gras production system. It shows that the feed explains most of the environmental impact of the product (more than 50% on average) and thus represents the most powerful action point. Several experiments were conducted to evaluate the technical feasibility, the response of the biological system and the consequences on system sustainability of a substitution of corn by sorghum in the diet of geese The studies show that the use of sorghum is technically possible and that complete substitution of corn by sorghum reduced the environmental impact of the production of 1 kg of foie gras (global warming potential: - 18%, acidification potential : - 12%, primary energy use: - 23%, water use: - 62%). However, some indicators were reduced, such as the intension reuptake product (- 17 pts) due to a paler color of the fatty liver, and viability during the overfeeding period (+ 4.6 pts in mortality rate). The overall results suggest that the use of sorghum in the diet of geese may improve the sustainability of the production of foie gras. Some adjustments in production practices are needed to optimize the use of this feedstuff.

International audience; The present experiment aimed at demonstrating that the Greylag geese (Anser anser), commonly used for the production of foie gras, are able to develop spontaneous hyperphagia and subsequent liver steatosis under specific handling conditions and without overfeeding. One hundred and eighty male geese were used in this experiment. After a period of feed restriction, at the age of 19 wk, corn was provided ad libitum. From wk 21 to 23, the daylight duration was progressively reduced from 10 to 7 h and kept as such until the end of the experiment (wk 31). Thirty birds were slaughtered at wk 19, 23, 25, 27, 29, and 31. During the first 2 wk after corn delivery, the average consumption rose up to 600 g/bird/d and decreased slowly thereafter to reach 270 g at wk 31. The liver weight increased from 95 (wk 19) to 514 g (wk 31), and most of these changes were due to the increase in liver lipid content from 6 to 50% of liver weight. There was no mortality during the experimental period. Histological observations indicate that the accumulation of fat in the livers occurred through a large increase in the size of the hepatocytes without modification of the cell boundaries and without any sign of inflammation or degeneration. Our data clearly show that under specific management conditions of feeding and photoperiod, the geese are able to initiate spontaneous liver steatosis. These results demonstrate their natural ability to store fat in the liver without any visible sign of tissue alteration. However, the variability in the response remains very high (at wk 31, the CV in liver weight was 45%). Further research is needed to better understand the origin of this variability.

Chantier qualité GA; International audience; The aim of this trial was to study the effects of substitution of yellow corn with sorghum during the growing-finishing (G period), overfeeding (O period), or both periods on magret and foie gras quality in geese. In total, 260 ganders were divided into 4 groups (65 birds in each) differing in the cereal (yellow corn or sorghum) included in the diet given during the G and the O periods, using a 2 × 2 factorial arrangement of treatments. The groups differed in the nature of the cereal in the diet offered to birds between 44 and 104 d of age (G period: a diet containing 500 g of sorghum/kg (SS and SC groups) or a diet containing 500 g of yellow corn/kg (CS and CC groups). The groups differed also in the diet offered to birds between 105 and 120 d of age (O period): 967 g of yellow corn/kg (SC and CC groups) or 965 g of sorghum/kg (SS and CS groups). At the end of the O period, the birds were slaughtered after 10 h of fasting to measure foie gras and breast muscle weight, color, and chemical composition. The mortality in the SC group was higher (P < 0.05) than in the other 3 groups (14.29 vs. 3.58%, average of the 3 groups). After overfeeding, birds fed with sorghum had foie gras that were heavier 984 vs. 885 g, in CS+SS vs. CC+SC groups, respectively; P < 0.001) and less yellow (18.03 vs. 23.97 for b*, in CS+SS vs. CC+SC groups, respectively, P < 0.001) than birds fed with corn. The substitution of yellow corn with sorghum during the G and O periods (SS group) increased the weight of the foie gras, but altered its color to a paler yellow. In contrast, a substitution during the G period only (SC group) resulted in increased mortality during the O period.

Chantier qualité GA; International audience; The mule duck, an interspecific hybrid obtained by crossing common duck (Anas platyrhynchos) females with Muscovy (Cairina moschata) drakes, is widely used for fatty liver production. The purpose of the present study was to detect and map single and pleiotropic QTL that segregate in the common duck species, and influence the expression of traits in their overfed mule duck offspring. To this end, we generated a common duck backcross (BC) population by crossing Kaiya and heavy Pekin experimental lines, which differ notably in regard to the BW and overfeeding ability of their mule progeny. The BC females were mated to Muscovy drakes and, on average, 4 male mule ducks hatched per BC female (1600 in total) and were measured for growth, metabolism during growth and the overfeeding period, overfeeding ability, and the quality of their breast meat and fatty liver. The phenotypic value of BC females was estimated for each trait by assigning to each female the mean value of the phenotypes of her offspring. Estimations allowed for variance, which depended on the number of male offspring per BC and the heritability of the trait considered. The genetic map used for QTL detection consisted of 91 microsatellite markers aggregated into 16 linkage groups (LG) covering a total of 778 cM. Twenty-two QTL were found to be significant at the 1% chromosome-wide threshold level using the single-trait detection option of the QTLMap software. Most of the QTL detected were related to the quality of breast meat and fatty liver: QTL for meat pH 20 min post mortem were mapped to LG4 (at the 1% genome-wide significance level), and QTL for meat lipid content and cooking losses were mapped to LG2a. The QTL related to fatty liver weight and liver protein and lipid content were for the most part detected on LG2c and LG9. Multitrait analysis highlighted the pleiotropic effects of QTL in these chromosome regions. Apart from the strong QTL for plasma triglyceride content at the end of the overfeeding period mapped to chromosome Z using single-trait analysis, all metabolic trait QTL were detected with the multitrait approach: the QTL mapped to LG14 and LG21 affected the plasma cholesterol and triglyceride contents, whereas the QTL mapped to LG2a seemed to impact glycemia and the basal plasma corticosterone content. A greater density genetic map will be needed to further fine map the QTL.

International audience; Raising and caring rabbits for purposes of companionship has become more popular within households. This has recently created attention in formulating balanced diets that include raw materials with nutritional characteristics capable of improving animal health status. The aim of this study was to compare, in balanced diets formulated for growing dwarf rabbits, the effect of the dietary inclusion of 3% microalga Spirulina (Arthrospira platensis, S) and/or 2.5% Thyme (Thymus vulgaris, T) leaves on the dietary fatty acid (FA) profile, the coefficients of total tract apparent digestibility (CTTAD), and the nutritive value of such diets on animal growth performance and health status. Four isonitrogenous (161 +/- 4 g/kg) and iso-energetic (16.8 +/- 0.1 MJ/kg) diets for growing pet rabbits were formulated: a control diet (C), a diet with 2.5% Thyme (T diet), a diet containing 3% Spirulina (S diet), and a diet with both 2.5% T and 3% S supplementations (TS diet). Diets were fed for 14 weeks to 120 dwarf rabbits (divided in 4 groups of 30 each) initially aged 7 weeks with a mean body weight of 643 +/- 4.7 g. Supplementing T and S resulted in diets numerically richer on polyunsaturated FA (PUFA), notably in C18:2n - 6 in S, T and TS diets and in C18:3n - 3 in S diets, although formulating diets with different proportions of raw materials to obtain equal energy contents may have played a role in the differences in the FA profile. The GLA (C18:3n - 6) level was 10-fold higher in the S-enriched diets. The n - 6/n - 3 ratio was favourably low in all diets (on average 2.6), and the lowest ratio was observed in the S and TS diets (2.12 and 2.53, respectively, although there were no statistically significant differences). At the end of the study females reached a higher body weight (P < 0.05) probably due to the higher feed intake during the experimental period, possibly as a result of reaching puberty. Dietary treatments did not negatively affect the animal growth performance. A decrease (P < 0.01) of the CTTAD of ether extract (0.87 vs 0.85 vs 0.85 vs 0.84, in C, T, S, and TS, respectively) was observed, which was probably due to the slight decrease of dietary EE content and the increase of PUFA proportion in the diets. The CTTAD of ADF and cellulose increased with TS addition compared to the C diet (0.22 vs 0.17 and 0.28 vs 0.22 for TS and C diets, respectively; P < 0.05). Morbidity and mortality were unaffected by the dietary treatment. We conclude that S and/or T can be included at a rate of 3% and 2.5% respectively in the diet of growing dwarf rabbits with no substantial effects on growth performance and energy or nutrients digestibility. At these rates of inclusion, S and T did not prevent animals from getting sick or dying during the 14 weeks of study period. A longer follow-up is necessary in companion dwarf rabbits to investigate whether S and T confer beneficial effects in healthy mature, elderly and debilitated animals. (c) 2012 Elsevier B.V. All rights reserved.

National audience; Pendant l'allaitement la lapine émet des fèces dures dans le nid, qui sont en partie ingérées par les lapereaux. L'objectif de notre étude est i) d'évaluer l'effet de l’ingestion de fèces maternelles au nid sur l'implantation du microbiote cæcal par séquençage 454 de la région V3-V4 des gènes codant pour l’ARN 16S, la croissance et la survie des lapereaux et ii) d’orienter le processus d'implantation du microbiote en substituant les fèces aternelles par des fèces issues d’autres femelles sous antibiothérapie ou non. Dans le lot témoin, les fèces maternelles sont dénombrées et laissées à disposition des lapereaux dans le nid (lot T, n=24 portées), dans le lot R (n=28 portées) les fèces sont comptées puis retirées. Dans les deux derniers lots les fèces maternelles sont comptées, retirées et remplacées par des fèces issues de femelles étrangères non traitées (E, n=28 portées) ou traitées aux antibiotiques (Eab, n=29 portées). L’apport de fèces de lapines étrangères multiplie par 3 le comportement de coprophagie du lapereau (p

International audience; Feeding has high economic and environmental costs in poultry production. The feeding of waterfowl for fatty liver production is largely based on the use of maize as an energy source.The aim of this trial was to study the effect of the form of presentation (whole grain or flour) and the amount (40.5, 56, or 100%, depending on the form) of sorghum in the overfeeding diet on the performance of geese. During overfeeding, a diet mainly composed of sorghum reduced the FCR of the geese and increased the weight of fatty liver, but reduced their commercial grading. The use of sorghum during geese overfeeding offers interesting prospects for a more sustainable fatty liver production system. Indeed, it could reduce the environmental effect of goose feeding while improving the flexibility of production systems, making it possible to use a cereal other than maize for overfeeding.

A reprendre; absent

International audience

International audience

International audience; The effects of protein replacement by digestible fibre fractions "DgF" (hemicellu-loses + water-insoluble pectins) on the digestive physiology of the weaned rabbit were analysed by comparing four diets with a linear increase of the digestible fibre:crude protein ratio "DgFP" (1.01, 1.16, 1.34 and 1.55 for DgFP1 to DgFP4 groups, respectively), without changes of poorly digestible fibre levels (acid detergent fibre = 190 g/kg). 12 male rabbits were allotted to each of the four diets at weaning (32 days), housed in metabolism cages up to 71 days of age, and fed freely one of the four diets. Faecal and urine excretion were individually measured from 43 to 47 days of age, and from 63 and 67 days. At 71 days of age, the caecal contents of DgFP1 and DgFP4 groups were sampled to assess microbial activity (pH, volatile fatty acids concentration, etc.). The organic matter digestibility was similar for the four diets, but decreased by 2 units (0.65-0.63, P

International audience; It has been suggested that the ability of live yeast to improve milk yield and weight gain in cattle is because the yeast stimulates bacterial activity within the rumen. However it remains unclear if this is a general stimulation of all species or a specific stimulation of certain species. Here we characterised the change in the bacterial population within the rumen of cattle fed supplemental live yeast. Three cannulated lactating cows received a daily ration (24 kg/d) of corn silage (61% of DM), concentrates (30% of DM), dehydrated alfalfa (9% of DM) and a minerals and vitamins mix (1% of DM). The effect of yeast (BIOSAF SC 47, Lesaffre Feed Additives, France; 0.5 or 5 g/d) was compared to a control (no additive) in a 363 Latin square design. The variation in the rumen bacterial community between treatments was assessed using Serial Analysis of V1 Ribosomal Sequence Tag (SARST-V1) and 454 pyrosequencing based on analysis of the 16S rRNA gene. Compared to the control diet supplementation of probiotic yeast maintained a healthy fermentation in the rumen of lactating cattle (higher VFA concentration [high yeast dose only], higher rumen pH, and lower Eh and lactate). These improvements were accompanied with a shift in the main fibrolytic group (Fibrobacter and Ruminococcus) and lactate utilising bacteria (Megasphaera and Selenomonas). In addition we have shown that the analysis of short V1 region of 16s rRNA gene (50-60 bp) could give as much phylogenetic information as a longer read (454 pyrosequencing of 250 bp). This study also highlights the difficulty of drawing conclusions on composition and diversity of complex microbiota because of the variation caused by the use of different methods (sequencing technology and/or analysis).

National audience; L’objectif de cette synthèse, centrée sur le lapereau de la naissance au sevrage, est de faire un constat de ses vulnérabilités, de présenter les outils physiologiques et comportementaux dont il dispose pour pallier en partie ces difficultés et enfin de proposer des pratiques d’élevage et des pistes de recherches pour sécuriser la période du sevrage. Le lapereau nait nu, incapable d’assurer une thermorégulation autonome suffisante et il n’est qu’en partie mature sur les plans sensoriel, physiologique et moteur. Ses interactions avec sa mère sont limitées (une tétée par jour). L’alimentation solide débute lorsque les lapereaux sont capables de quitter le nid ; ils accèdent alors au même aliment que leur mère bien qu’ils n’ont pas les mêmes besoins. Certaines maladies rencontrées au nid peuvent être dues à des conditions d’élevage inadéquates. Pourtant cette espèce a développé des adaptations physiologiques et comportementales qui permettent d’assurer la survie des jeunes. L’existence d’une phéromone mammaire, le comportement coprophage au nid, la dynamique de maturation du système digestif sont autant d’atouts qui contribuent à la robustesse des lapereaux. Les leviers d’action potentiellement favorables concernent des pratiques d’élevage (manipulations des nids, homogénéisation des tailles et poids de portée, allaitement contrôlé) et l’utilisation d’animaux sélectionnés pour l’homogénéité des portées ou des stratégies d’alimentation (alimentation séparée mère jeune, alimentation précoce).

absent

National audience

National audience

International audience; A divergent selection for digestive disorders, R for resistance and S for sensitivity, based on routine observational data of signs of enteropathy, was carried out in AGP39 and AGP59 commercial lines of the Hypharm breeding company. Two successive batches (B1 and B2) of 178 crossbred animals, 89 R and 89 S, were produced by mating AGP39 well evaluated bucks with AGP59 well evaluated does and AGP39 bad evaluated bucks with AGP59 bad evaluated does, respectively. In each batch, 27 R animals (RC) and 27 animals (SC) were chosen to constitute the control group while 62 R animals (RI) and 62 S animals (SI) were chosen for inoculation. Individual EBV of animals of the RI group and of the SI group was calculated as the mean of their sire and dam’s EBV. In each batch, 31 animals with the lowest EBV in the RI group and 31 animals with the highest EBV in the SI group were sorted to constitute the group RRI and the group SSI, respectively.Young rabbits were carried from Hypharm to the INRA Experimental Platform for Infectious Disease (PFIE) just after weaning at 30 days of age. Inoculated rabbits received 105 bacteria of the strain LY265, E. Coli O103:H2:K-, rhamnose negative (Licois et al., 1992), by oral administration, at 37 days of age. All animals were weighed and checked for clinical symptoms just before the inoculation, 2 days, 6 days, 9 days and 13 days after the inoculation. Average daily weight gain was calculated for each interval. Individual mortality was recorded daily. 13 days after inoculation, 9 rabbits of each sub-group were sacrificed to measure pH of the caecal digesta and for caecum and caecum appendix weighing. The impact of the E. coli challenge was significant for growth and for the caecum relative weight. Although mortality tended to be higher in sensitive animals than in resistant animals in batch 1 (p=0.12) there was no significant difference between RI and SI groups for cumulative mortality, daily weight gain and caecum measurements. Mortality was significantly lower (p=0.04) in RRI group than in SSI group at day 11, day 12 and day 13 (31.8 %, 34,8 % and 36.6 % vs. 50 %, 5.1 % and 54.7 % respectively). This difference corresponded to 11 animals for each of the 3 periods.

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International audience; The nutritive value and potential use of sun-dried common reed (Phragmites australis) leaves "CRL", for the growing rabbit was studied by comparing 3 diets (regression method) containing an increasing incorporation of CRL: 0% (control, CRL0), 15 % (CRL15) and 30% (CRL30) in substitution to the control diet (356 g NDF and 197 g CP/ kg). Three groups of 37 rabbits (individually caged) were fed ad libitum the three diets from weaning (35 d, mean weight: 722 ± 142 g) to 77 d of age. The faecal digestibility of the diets was measured between 42 and 46 days of age on 10 rabbits per group. Common reed leaves can be considered as a roughage since it contained 64% of NDF (38% of ADF) and 10.2% of crude protein. The digestible energy (DE) content of CRL calculated by regression was null (-1.8±0.29 MJ/kg as fed) that classed this roughage as a source of ballast, probably active for transit stimulation. The digestibility of crude protein reached 28.5%, corresponding to a digestible crude protein concentration of 29.0±5.6 g/kg as fed basis. Health status was not affected by the CRL incorporation rate. However, incorporation of CRL in feeds impaired the growth less than 10% (34.2 for CRL0 vs 31.4 g/d for CRL15 and CRL30, from 35 to 77d old) and feed conversion 16%.

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International audience

Chantier qualité spécifique "Auteurs Externes" département de Génétique animale : uniquement liaison auteur au référentiel HR-Access; Genetic parameters of feed efficiency and growth traits were estimated in two selected rabbit lines after 6 generations of selection. The ConsR line was selected for residual feed intake (RFI) under ad libitum feeding. The AlimR line was selected for average daily gain (ADG from 30 to 63 days) under restricted feeding corresponding to 80 % of ad libitum feed intake of control animals. Estimates of heritability of ADG and FCR (feed conversion ratio) were higher in the AlimR line than in the ConsR line, while estimates of heritability of weight at 30 and 63 days-old were similar between lines. Heritability of ADG (0.25), the selection criterion of the AlimR line, was higher than RFI (0.15), the selection criterion of the ConsR line. Estimates of heritability and genetic correlations between weaning weight, weight at 63 days, ADG and FCR are also presented for each line.

International audience; Due to the role of soluble fibre (SF) on the digestive physiology and gut health of post-weaning rabbits and to the lack of reference methods for SF determination, in the framework of the harmonization activity on rabbit science methodologies carried out by EGRAN (European Group on Rabbit Nutrition), a collaborative study was achieved on the determination of total dietary fibre (TDF), aNDF corrected for protein and ash (aNDFcorr) and SF calculated as the difference between TDF and aNDFcorr. Five EGRAN laboratories analysed nine samples: four compound diets and five raw materials (alfalfa meal, wheat bran, grape marc, sunflower meal, sugarbeet pulp) with different levels of fibre fractions and SF. Each sample was analysed 3 runs for TDF and aNDFcorr. TDF was analysed according to the AOAC Method 991.43 using the kit and the procedure of Megazyme®. TDF averaged 48.2% DM, with one laboratory having higher values (49.3% vs 47.9%; P

International audience; The aim of this trial was to study the effects of cereal (corn or sorghum) and of the presentationof the diet (pelleted diet or a mixture with cereal)on the performance of geese. In total, 480 one-day-oldgeese were divided into 4 groups differing in the dietthey received between 52 and 102 d of age: a pelleteddiet containing 500 g of sorghum/kg (CS group; AMEn11.29 MJ/kg, CP 16.70%); a mixture containing 500g of protein-rich pellets and 500 g of sorghum wholeseeds/kg (MS group; AMEn 11.61 MJ/kg, CP 14.30%);a pelleted diet containing 500 g of corn/kg (group CC;AMEn 11.33 MJ/kg, CP 16.40%); and a mixture containing500 g of protein-rich pellets and 500 g of cornmash/kg (group MC; AMEn 11.48 MJ/kg, CP 14.50%).From 102 to 117 d, 33 birds/sex/group were force-fedwith corn. Between 52 and 102 d of age, individual BWand collective feed intake (40 birds/pen) were measuredweekly. Body traits were measured at 69, 96, and 117d and the volume of the crop was measured at 102 dof age. The cereal had no significant effect on totalfeed intake (15,028 g, NS) or BW (5,811 g, NS) butthe breast development at 102 d was less in birds fedsorghum compared with corn (−4.9%; P < 0.05). Feedintake (+8.4% between 69 and 102 d; P < 0.001), BW(+3.9%; P < 0.001) and gut development (+9.3%; P< 0.001) were higher when the diet was offered as amixture compared with a complete pelleted diet. Thebirds fed the complete pelleted diets had a larger crop(+10.1%; P < 0.05) than others. The cereal and thepresentation of the diet had no effect on the body traitsat the end of the force feeding. The results suggest thatthe use of sorghum whole seeds is interesting for feedinggeese.

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International audience; Fumonisins (FBs) are mycotoxins that are found worldwide in maize and maize products. Their main toxic effects have been well characterized in poultry, but differences between species have been demonstrated. Ducks appeared very sensitive to toxicity, whereas turkeys are more resistant. At the same time, alterations of sphingolipid metabolism, with an increase of the concentration of the free sphinganine (Sa) in serum and liver, have been demonstrated in the two species, but the link between the toxicity of FBs and Sa accumulation remains difficult to interpret. The aim of the present work was to compare the effects of FBs (10 mg FBI + FB2/kg body weight) on sphingolipid metabolism in ducks and turkeys. Growth, feed consumption, and serum biochemistry were also investigated to evaluate toxicity. The main results showed that FBs increased Sa concentrations in liver and serum in ducks and turkeys, but these accumulations were not directly correlated with toxicity. Sa accumulation was higher in the livers of turkeys than in ducks, whereas Sa levels were higher in the sera of ducks than in turkeys. Hepatic toxicity was more pronounced in ducks than in turkeys and accompanied a decrease of body weight and an increase of serum biochemistry in ducks bur not in turkeys. So, although FBs increase Sa concentration in the livers of both species, this effect is not directly proportional to toxicity. The mechanisms of FB toxicity and/or the mechanisms of protection of ducks and turkeys to the Sa accumulation within the liver remain to be established.

International audience; This study investigated the effects of various stunning methods on the quality of French ‘foie gras’ in ducks and geese. The ducks (n530 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130mA, 4 s), head-only electrical stunning (50 Hz AC, 600mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)–O2 (30%)–N2 (30%), for 2min followed by phase 2, CO2 .85% in air, for 2min). The same methods (except head-only stunning which was not applied) were used in geese (n540 per group). The weight of the liver at slaughter was not affected by the stunning techniques, neither was its colour (L*, a*, b* coordinates), despite the differences in bleeding rate between the stunning treatments. The loss of fat during the cooking of canned fatty liver did not depend upon stunning treatment. Some appearance defects of raw fatty livers were significantly affected by the treatment: mechanical and head-only stunning induced higher incidence of petechial haemorrhages in duck liver, whereas in geese, incidence of superficial haemorrhages was significantly higher after CAS and water-bath stunning. The calculation of an overall score based on the incidence and severity of the different appearance defects observed in the present experiment showed that CAS was associated with the least favourable position in ducks as well as in geese, compared to the other treatments. The commercial grading of ducks and geese fatty livers, carried out by an expert from the industry, clearly showed the detrimental effect of CAS on the commercial value of raw livers. CAS, under the conditions applied in the present work cannot be recommended, because of its drastic effect on liver quality. The underlying mechanisms deserve further investigations.

International audience; The effects of a quantitative feed restriction on the digestive physiology of the young rabbit remain largely unclear. Several digestive functions were thus analysed in the rabbit after weaning, using a monofactorial design that produces a linear reduction of the intake, from ad libitum (AL group) to 80%, 70% and 60% of AL (I80, I70 and I60). The restriction programme was applied by giving a daily meal during 21 days after weaning (34 days), and then a 4-day transition period was managed where the feed intake was fixed at 80% of the AL group, before to be fed ad libitum till 69 days of age. The young rabbit quickly adapted to the restriction programme, since within 4 days after weaning they ate totally their ration within 6–7 h after the feed distribution at 8:00, while AL animals consumed 75% of their feed between 15:00 and 8:00. From 55 to 59 days old, rabbits of I70 and I60 groups reached the intake of the I80 group within 1 day, and then the feed intake of restricted animals increased progressively without over-eating. From 54 to 69 days old, the intake of the four groups did not differ and averaged 143.7 g/day per rabbit. During restriction, the live weight and the weight gain decreased linearly with the restriction level. From 55 to 69 days, the weight gain increased linearly according to the restriction level previously applied, but the final weight of restricted rabbits remained lower than AL ones (23%, 25% and 27%, respectively, for I80, I70 and I60). After 7 days of restriction, the digestibility was not significantly affected by the restriction level, except for crude protein that presented a slightly higher (11.5 unit, P50.05) coefficient in I70 and I60 groups. The mean retention time (MRT) of particles increased by 50% for restricted animals (mean: 26.2 h for I80 and I60) compared to the AL ones, while that of the liquid phase (three times longer than the particles) was linearly and moderately increased with restriction (120% between AL and I60). In restricted groups, the caecal pH was lower (20.3 unit, P,0.05) and could be related to their higher volatile fatty acid (VFA) concentration (116 mmol/l compared to AL, P,0.05). The fermentation pattern, ammonia concentration and the caecal bacterial fibrolytic activity remained similar among treatments, although the butyrate proportion tended to be higher in restricted animals. Impact of feed restriction on performances and digestive health is reported in the second part of this study.

International audience; This study investigated the effects of various stunning methods on the quality of carcass and meat in ducks and geese force-fed for the production of French ‘ foie gras’. The ducks (n530 per group) were stunned with one of the following techniques: electrical stunning in a water bath (50 Hz AC, 130 mA, 4 s), head-only electrical stunning (50 Hz AC, 600mA, 4 s), mechanical stunning (captive bolt) and controlled atmosphere stunning (CAS: phase 1, CO2 (40%)–O2 (30%)–N2 (30%), for 2 min followed by phase 2, CO2.85% in air, for 2 min). The same methods (except head-only stunning which was not applied) were used in geese (n540 per group). During the first 5 min after slaughter, the stunning techniques that did not kill the animals were associated with a high incidence of head movements (mechanical and electrical head-only stunning), convulsions and convulsive wing flapping (mechanical stunning), in both species. Consequently, the rate of post-mortem pH fall in breast muscle was enhanced and the meat was paler when measured at 24 h or 6 days post mortem ( L*, a*, b* coordinates). In ducks, the animals stunned in the water bath showed the lowest bleeding efficiency, compared to the three other procedures. In geese, the mechanical stunning allowed the highest recovery of blood compared to the CAS and the water-bath methods. Meat texture assessed instrumentally and fluid losses during storage and processing were not affected by the stunning method in any species. Sensory analysis showed a higher score for bloody appearance of raw meat in ducks stunned with the methods that kill before neck cutting (water-bath and CAS). This effect was, however, not linked to the rate of bleeding. The sensory properties of cooked meat were not affected by the stunning method. In both ducks and geese, CAS was associated with the lowest rate of fractures of humeral bone but CAS-stunned geese showed the most engorged wing veins. Overall, these results show the positive effect of CAS on the appearance defects of carcass and meat of ducks and geese, and, on the contrary, they confirm the detrimental effects of water-bath stunning on these criteria. However, the incidences on meat sensory qualities were scarce.

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National audience

International audience; Waterfowl production has been on an upward trend and has become increasingly important around the world over time. The production of ducks worldwide in 2010 was 6-fold greater that of 1961, and that of geese was 9.8-fold over the same period. The progress in waterfowl production represents not only an increase in the quantity of the product, but also in quality. Waterfowl performance progress, genetics and breeding, reproduction, nutrition, management and housing, and product quality and utilisation are discussed in this article, alongside a review of the history of the Waterfowl Working Group (WWG) which was established in 1969 as Working Group 8 under the European Federation (EF). After moving to the Asian Pacific Federation (APF) in 2011, it became Working Group 2.

International audience; Among trans fatty acids, trans-10,cis-12 CLA has negative effects on cow milk fat production and can affect human health. In high-yielding dairy cows, a shift from the trans-11 to the trans-10 pathway of biohydrogenation (BH) can occur in the rumen of cows receiving high-concentrate diets, especially when the diet is supplemented with unsaturated fat sources. In some but not all experiments, vitamin E has been shown to control this shift To ascertain the effects of vitamin E on this shift of BH pathway, 2 studies were conducted. The first study explored in vitro the effects of addition of natural (RRR-alpha-tocopherol acetate) and synthetic (DL-alpha-tocopherol acetate) vitamin E. Compared with control and synthetic vitamin E, the natural form resulted in a greater trans-10 I trans-11 ratio; however, the effect was very low, suggesting that vitamin E was neither a limiting factor for rumen BH nor a modulator of the BH pathway. An in vivo study investigated the effect of natural vitamin E (RRR-alpha-tocopherol) on this shift and subsequent milk fat depression. Six rumen-fistulated lactating Holstein cows were assigned to a 2 x 2 crossover design. Cows received 20-kg DM of a control diet based on corn silage with 22% of wheat, and after 2 wk of adaptation, the diet was supplemented with 600 g of sunflower oil for 2 more weeks. During the last week of this 4-wk experimental period, cows were divided into 2 groups: an unsupplemented control group and a group receiving 11 g of RRR-alpha-tocopherol acetate per day. A trans-10 shift of ruminal BH associated with milk fat depression due to oil supplementation of a high-wheat diet was observed, but vitamin E supplementation of dairy cows did not result in a reversal toward a trans-11 BH pathway, and did not restore milk fat content.

International audience; For determining the nutritive value of Sulla (Hedysarum flexuosum), containing organic matter (OM) 84.3; crude protein (CP) 22.5; neutral detergent fibre (NDF) 49.0; acid detergent fibre (ADF) 34.3; acid detergent lignin (ADL) 10.8 % on DM basis, sixteen rabbits of Algerian white local population (individually caged) weaned at 35d old (mean body weight: 541±29g) were fedad libitum fresh green Sulla as a sole feed during five weeks. The faecal digestibility of the Sulla was measured between 49 and 53 days of age on 12 rabbits. The digestibility of DM, OM, CP, NDF and ADF was 52.3; 52; 64.4; 35.5 and 28%, respectively. The average DM intake reached 114.2 g/d (125.6 g/kg LW 0.75), while the digestible CP intake was 17.7g/d (19.5 g/kg LW 0.75 d) and that of digestible energy (DE) was 1.05 MJ/d (1.15 MJ/kg LW 0.75). These digestible nutrients intake allowed to meet not only the maintenance requirement, but also to support a growth rate of 18.9 g/d. The digestible energy concentration of the fresh Sulla was 9.2±0.15 MJ/kg DM, while the digestible crude protein concentration was 145±1.8g/kg DM. Harvested at young stage of growth, Sulla could be considered as a good and balanced fibre source for the growing rabbit and comparable to other good quality forages such as alfalfa and ryegrass.

Background: beta-Carotene is an important precursor of vitamin A, and is associated with bovine fertility. beta-Carotene concentrations in plasma are used to optimize beta-carotene supplementation in cattle, but measurement requires specialized equipment to separate plasma and extract and measure beta-carotene, either using spectrophotometry or high performance liquid chromatography (HPLC). Objective: The objective of this study was to validate a new 2-step point-of-care (POC) assay for measuring beta-carotene in whole blood and plasma. Methods: beta-carotene concentrations in plasma from 166 cows were measured using HPLC and compared with results obtained using a POC assay, the iCheck-iEx-Carotene test kit. Whole blood samples from 23 of these cattle were also evaluated using the POC assay and compared with HPLC-plasma results from the same 23 animals. The POC assay includes an extraction vial (iEx Carotene) and hand-held photometer (iCheck Carotene). Results: Concentrations of beta-carotene in plasma measured using the POC assay ranged from 0.40 to 15.84 mg/L (n = 166). No differences were observed between methods for assay of plasma (mean +/- SD; n = 166): HPLC-plasma 4.23 +/- 2.35 mg/L; POC-plasma 4.49 +/- 2.36 mg/L. Similar good agreement was found when plasma analyzed using HPLC was compared with whole blood analyzed using the POC system (n = 23): HPLC-plasma 3.46 +/- 2.12 mg/L; POC-whole blood 3.67 +/- 2.29 mg/L. Conclusions: Concentrations of beta-carotene can be measured in blood and plasma from cattle easily and rapidly using a POC assay, and results are comparable to those obtained by the highly sophisticated HPLC method. Immediate feedback regarding beta-carotene deficiency facilitates rapid and appropriate optimization of beta-carotene supplementation in feed.

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