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International audience; Locusts are able to migrate over long distances across areas with different vegetation structures. This work investigates how the spatial arrangement of vegetation might affect locust collective motion. The behavior of groups of third instar Schistocerca gregaria hoppers that had been fed or starved for 24 h was studied experimentally. Food patches were introduced into a circular arena where locust groups were marching. We tested two different types of food distribution: uniform and clustered. The starved locust groups were used to simulate how encountering vegetation affected locusts after crossing a large bare area. We analyzed the directed motion and mean speed of the locust groups. On the small scale of the arena, the results did not show any effects of vegetation distribution on the oriented motion and mean speed of the groups (fed group). However, encountering vegetation greatly affected the oriented movement and walking speed in the starved group, mimicking the crossing of a large bare area (group starved for 24 h). After feeding, the individuals entered a post-prandial period. That period was significantly longer for the starved hoppers than for the fed hoppers. After the post-prandial period, the hoppers started marching and did not return to feed on the food. It is therefore suggested that the marching activity of hoppers is not directly related to their hunger level. The effect of the spatial distribution of vegetation on the hunger status of hoppers and the implication for barrier treatments used in locust control are further discussed.

International audience; Galactolipids are the most abundant lipids on earth where they are mainly found in photosynthetic membranes of plant, algae, and cyanobacteria. Pancreatic lipase-related protein 2 (PLRP2) is an enzyme with galactolipase activity allowing mammals, especially herbivores, to digest this important source of fatty acids. We present a method for the quantitative analysis of galactolipids and galactosylated products resulting from their digestion by guinea pig PLRP2 (GPLRP2), using thin-layer-chromatography (TLC), thymolsulfuric acid as derivatization reagent and scanning densitometry for detection. Thymolsulfuric acid reagent has been used for the colorimetric detection of carbohydrates. It is shown here that the derivatization of galactosyl group from galactolipids by this reagent is not affected by the bound acyl glycerol, acyl chains length and number of galactose residues in the polar head. This allowed quantifying simultaneously the initial substrate and all galactosylated products generated upon the hydrolysis of monogalactosyl di-octanoylglycerol (C8-MGDG) by GPLRP2 using a single calibration with C8-MGDG as reference standard. The reaction products, monogalactosyl monooctanoyl glycerol (C8-MGMG) and monogalactosyl glycerol (MGG), were identified and quantified, MGG being recovered from the aqueous and analyzed by a separate TLC analysis. This method is therefore suitable to quantify the products resulting from the release of both fatty acids present in MGDG and thereby shows that PLRP2 can contribute to the complete digestion of galactolipids and further intestinal absorption of their fatty acids.

Le présent guide est destiné au-delà des partenaires du projet CAMELMILK, à tous les éleveurs et néo-éleveurs qui souhaitent se lancer dans l'élevage des chamelles laitières. Il a pour ambition de fournir les bases de la connaissance de la physiologie de cet animal en lien direct avec les performances de production qu'on peut en attendre, et un ensemble de conseils en matière de gestion de l'élevage camelin laitier. Se voulant pratique, il aborde l'ensemble des questions afférentes à la production, la reproduction, l'alimentation ou la gestion technico-économique sans entrer dans des détails à caractère " scientifique ", mais en visant l'acquisition de compétences relevant plus du savoir-faire que d'investigation biologique. Ce guide abordera donc successivement (i) les bases physiologiques de la reproduction, de la lactation et de l'alimentation, (ii) la gestion technico-économique de la ferme laitière (gestion de la reproduction, de l'alimentation et de la lactation) incluant les aspects transformation des produits, et (iii) la gestion de la santé et de l'hygiène en élevage.

Microfiltered noni (Morinda citrifolia) juice was given by cannulation to 6 Wistar rats for 13 days; the rats were also fed on a standard food formulation containing whole soy bean flour. Twenty-four hour urine was collected before and after the nutritional intervention and was analyzed by UPLC-DAD/ESI+-QTof/MS to perform an untargeted metabolomics study. A supervised multivariate OSC-PLS-DA analysis was performed to discriminate between urine samples. Among the top 10 most discriminant ions, 8 compounds were tentatively identified. Six were significantly increased after noni juice ingestion: the glucuronidate form of S-(-) equol, daidzein, 2 isomers of dihydroxyquinoline, naphthyl and hippuric acid. On the contrary, the urinary excretion of the oligosaccharides stachyose and raffinose, was significantly reduced. Still highly statistically significant, glucuronated genistein and glycetein were also elevated in urine after noni juice ingestion. Noni juice appeared to considerably enhance the bioavailability of soy isoflavone and modify the metabolism of soy oligosaccharides. Universidad de Costa Rica/[735-A2-502]/UCR/Costa Rica Universidad de Costa Rica/[735-A6-912]/UCR/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Básicas::Centro de Investigaciones en Productos Naturales (CIPRONA) UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Instituto de Investigaciones Farmacéuticas (INIFAR)

In this study, the interactions between two semi-aquatic mammals, the endangered Pyrenean desman Galemys pyrenaicus and the Eurasian water shrew Neomys fodiens, were investigated through the analysis of their summer diet using next-generation sequencing methods, combined with analyses of prey selectivity and trophic overlap. The diet of these predators was highly diverse including 194 and 205 genera for G. pyrenaicus and N. fodiens respectively. Overall, both species exhibited rather non-selective foraging strategies as the most frequently consumed invertebrates were also the most frequent and abundant in the streams. This supported a generalist foraging behaviour for G. pyrenaicus and N. fodiens in the study area. The Pianka index (0.4) indicated a significant but moderate dietary overlap as G. pyrenaicus mostly relied on prey with aquatic stages whereas prey of N. fodiens were mainly terrestrial. Moreover, no difference in G. pyrenaicus prey consumption was found in presence or absence of N. fodiens. A differential use of trophic resources through mechanisms such as plastic feeding behaviour or differences in foraging micro-habitat are likely to facilitate the coexistence between these two mammal species.

The present paper aims to propose an evaluation of the ingestibility and selectivity of food items, as well as the effect of different levels of energetic supplementation and concentrate feed ingredients, on camels dry matter intake (DMI). With this goal, an experiment on six dairy she-camels receiving every 14–15 days a progressive high level of concentrates was conducted. During experimental periods, DMI ranged from 1.30 to 1.96 kg DMI per 100 kg of body weight (BW) was used. In an effort to examine the feeding behavior, a sign of reduced appetite was observed. Based on the results, it can be unveiled that as soon as the concentrate intake (CI) reached a quantity of 3.3 kg DM/d, which represented 51% of the total DM intake, the camels did not appear to ingest more exceedingly and their eating activity occurred in a distributed manner during daytime. Besides, an amount of concentrate supplements, which can characterize a high selectivity to fermentable carbohydrates, fed camels consumed dates, as well. In addition, food items such as corn, soybean meal, and dates that are rich in simple nutrient improved DMI. However, the statistical analysis did not reveal any statistically significant negative effect of concentrates on hay ingestion used in the experimental diets. Therefore, the intake of concentrates did not substitute the ingested amount of hay. Furthermore, the immense incorporation of dates and the increase in energy density of diet (DER) negatively affected the ingestion of hay.

The idea to use blood biochemical parameters to evaluate the health and nutritional status of one individual is an old practice in human medicine. In veterinary medicine, blood analyses have been proposed to help first the diagnosis of cattle diseases since nearly one century. But they were initially developed only in the sixties in the specialized research laboratories, in Veterinary Services and later in the veterinary cabinets. Currently, a whole set of analyses that are critical for vets' diagnostics and farmers' decision-making is proposed to the livestock and animal health actors to define metabolic, biochemical or blood profiles, Cattle is undoubtedly the more investigated species among farm animals. Data on sheep and goat are numerous, but it is already more disparate for camel. The biochemical investigations are convenient if (i) the purpose of the analyses is clear and based on a clear sampling procedure plan, (ii) the physiological variation factors are taken in account for convenient interpretation of the results, (iii) the sampling protocol is respected (for example blood sampling before feeding), (iv) the interpretation is based on a set of animals due to the between-individual variability, and on a pattern of parameters (v) the confusion between statistical difference and biological significance is avoided. Regarding the camel specificities, the followings could be listed: (i) predominance of polynuclear neutrophils in its white cell formula, (ii) maintenance of hematocrit in case of physical effort, (iii) osmolality resistance, (iv) relative hyperglycemia, (v) absence of ketone bodies, (vi) low plasma cholesterol in plasma concentration, (vii) susceptibility to hyperuremia, (viii) thermo-resistance of alkaline phosphatases, (ix) maintenance of metalloenzymes activities in case of mineral deficiency, (x) maintenance of electrolytes balance in dehydrated animals, (xi) low plasma zinc concentration in supplemented camel, (xii) higher sensitivity to selenium toxicosis, (xiii) richness of camel milk in vitamin C, (xiv) richness of plasma in vitamin D, (xv) seasonal pattern of testosterone, (xvi) decreasing insulin responsiveness with age of the young calves to induced hyperglycemia.

Abnormal glucose metabolism, hyperlipidaemia profiles and high levels of radical oxygen species (ROS) are classic features of diabetes. This study evaluates the effect of the consumption of two different blackberry beverages at 25 and 12.5% given orally for 40 days to rats with streptozotocin induced diabetes. The lower dose of blackberry (12.5%) non-statistically decreased glycaemia (−10.4%), triacylglycerols (−4.6%) and cholesterol (−21.0%). These differences were not statistically significant. The higher dose of blackberry (25%) significantly decreased glucose (−48.6%), triacylglycerols (−43.5%) and cholesterol (−28.6%). The higher dose of blackberry (25%) improved plasma antioxidant capacity, reduced the levels of lipid peroxidation in plasma (−19%) and in kidney (−23%). Blackberry intake did not improve catalase, suggesting that attenuation of oxidative stress via scavenging activities rather than improving the activities of antioxidant enzymes. These results provide promising data for this blackberry as a dietary adjuvant to the pharmacological management of diabetes. Consejo Nacional de Rectores/[801-B1-655]/CONARE/Costa Rica UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA)

International audience; ABSTRACT: The feeding ecology of leptocephali has remained poorly understood because they apparently feed on particulate organic matter (POM), which varies in composition, and it is unclear which components of the POM they assimilate. The δ13C and δ15N stable isotope (SI) and fatty acid (FA) compositions of 3 families of leptocephali and POM were compared in 3 latitudinal current zones of the western South Pacific. The δ15N signatures of leptocephali and POM overlapped, with both having their lowest values in the southern current zone. POM in general (across all zones) contained 38 FAs and was rich in saturated FAs (SFA) (16:0, 18:0, 14:0), while leptocephali contained 50 FAs, with high proportions of 16:0, and higher contributions of 22:6ω3, 20:5ω3, 18:1ω9, 16:1ω7 and other FAs than found in the POM. Serrivomeridae leptocephali in the north had higher δ15N signatures and were also distinguished from Nemichthyidae and Muraenidae larvae by their FA compositions (higher SFAs, lower 22:6ω3 and 20:5ω3). Although SI signatures of the Serrivomeridae larvae did not clearly vary with size, 16:0 and 18:0 FA proportions decreased with increasing larval size, and 22:6ω3 and 16:1ω7 increased in larger larvae. Correspondences between the latitudinal variations in nitrogen SI signatures and FA compositions of POM with those of leptocephali and the presence of FA markers of both autotrophic and heterotrophic organisms were consistent with leptocephali feeding on POM. POM can contain various materials from primary producers and heterotrophic microorganisms, but differences in the SI signatures and FA compositions in leptocephali remain to be explained through further research

Two experiments were conducted to investigate the use of sorghum, cottonseed meal and millet in broiler diets and their interaction when they are used simultaneously. In Experiment 1, a corn-soybean meal control diet was compared with eight experimental treatments based on low tannin sorghum (S30, S45 and S60), cottonseed meal (CM15, CM40) or both ingredients included in the same diet (S30/CM40, S45/CM25 and S60CM15). Results showed that BW gain was not affected by the inclusion of sorghum or cottonseed meal. However, feed intake tended to be affected by the cereal type with the highest values with sorghum-based diets. Feed conversion ratio increased (P

International audience; BackgroundIn a context of increasing resistance of both vectors toward main classes of insecticides used in public health and parasites toward anti-malarial drugs, development of new and complementary molecules or control approaches is fundamental to achieve the objective of controlling or even eliminating malaria. Concerning vector control, the sterile insect technique and other genetic control approaches are among promising complementary tools in an integrated management strategy for malaria control. These approaches rely not only on a good understanding of vector biology (especially during larval stages), but also on the availability of adequate supplies and protocols for efficient mosquito rearing. The aim of this study was to assess the factors impacting the life history of Anopheles coluzzii mosquitoes at the larval stage, in the context of genetic and sterile insect approaches to control malaria vectors.MethodsThe effect of different larval diets and larval rearing densities on the development of An. coluzzii were evaluated in the laboratory. Emergence rate (ER), pre-imaginal developmental time (DT) and adult wing length (WL) were measured under different food regimes. Four diets were tested among which three were provided by the Insect Pest Control Laboratory (IPCL) of the FAO/IAEA Joint division.ResultsData showed significant differences in the quality of the different diets and suggested a negative density dependence in all three life history parameters measured under tested rearing conditions. ER and WL increased with food availability, but decreased with increasing larval density. Conversely DT was shortened with increasing food availability but increased with larval density. These data demonstrates intraspecific larval competition modulated by food amount and space availability. Of the four diets tested, the one made of a mix of tuna meal, bovine liver powder, brewer's yeast, squid liver powder and vitamin mix (diet 2) yielded the best results as it produced a good balance between ER, DT and WL. Food availability for optimal development (highest survival at shortest time) was in the range of 180-400 mu g/larvae/day for the three diets provided by the IPCL.ConclusionThere is an interaction between diet type, diet concentration and larval density. Best results in terms of optimal larvae development parameters happen when moderately high values of those three variables are observed.

The incidence of obesity and its metabolic complications are rapidly increasing and become a major public health issue. This trend is associated with an increase in the prevalence of non-alcoholic fatty liver disease (NAFLD), insulin resistance and diabetes. The sequence of events leading to NAFLD progression and mitochondrial dysfunction and their interrelation remains to be elucidated. This study aimed to explore the installation and progression of NAFLD and its association with the liver mitochondrial structure and activity changes in rats fed an obesogenic diet up to 20 weeks. Male Wistar rats were fed either a standard or high-fat–high-fructose (HFHFR) diet and killed on 4, 8, 12, 16 and 20 weeks of diet intake. Rats fed the HFHFR diet developed mildly overweight, associated with increased adipose tissue weight, hepatic steatosis, hyperglycaemia and hyperinsulinaemia after 8 weeks of HFHFR diet. Hepatic steatosis and many biochemical modifications plateaued at 8–12 weeks of HFHFR diet with slight amelioration afterwards. Interestingly, several biochemical and physiological parameters of mitochondrial function, as well as its phospholipid composition, in particular cardiolipin content, were tightly related to hepatic steatosis installation. These results showed once again the interrelation between hepatic steatosis development and mitochondrial activity alterations without being able to say whether the mitochondrial alterations preceded or followed the installation/progression of hepatic steatosis. Because both hepatic steatosis and mitochondrial alterations occurred as early as 4 weeks of diet, future studies should consider these four 1st weeks to reveal the exact interconnection between these major consequences of obesogenic diet intake.

International audience; The feeding behavior and fodder intake of cattle, sheep and goats grazing semi-arid sub-Saharan Africa rangelands in Senegal was studied over a one-year cycle. The objective of the study was to improve the assessment of fodder intake by livestock grazing rangelands in semi-arid sub-Saharan Africa, The study was conducted in the service area of a borehole that includes 354 pastoral settlements and a total of 11,000 cattle and 1800 small ruminants. The grazing behavior of five steers was monitored monthly. Their forage intake was estimated every month from hand plucking simulations of all the bites of forage taken by the steers 24 h out of 48. The feces they excreted during the day were collected in fecal bags. Near infrared spectrum (NIRS) images were used to analyze 80 samples of these feces, and the data were then added to an existing reference data set to predict fodder intake and digestibility using NIBS. The complete and contextualized data base was then used to predict the daily fodder intake and its digestibility by cattle, sheep and goats whose fresh feces were systematically and randomly sampled every month in the study area (768 samples). Annual means of the daily dry matter fodder intake were 68.4 +/- 6.4 g/kg LW0.75 or 17.2 +/- 1.7 g/kg LW for cattle, 73.1 +/- 5.3 g/kg LW07.5 or 34.3 +/- 2.8 g/kg LW for sheep, and 74.7 +/- 8.7 g/kg LW0.75 or 37.1 +/- 4.4 g/kg LW for goats. The annual mean organic matter digestibility of grazed fodder was higher for goats (67.4 +/- 3.9%) than for sheep (64.1 +/- 3.2%) and cattle (59.3 +/- 3.8%). The seasonal variations in diet digestibility were bigger for cattle than for sheep, and smaller for goats. The standard reference used to assess livestock fodder intake in tropical Africa relies on a fixed daily intake rate per unit live weight of 25 g/kg LW. Our results show that this method overestimates (+ 45%) intake by cattle, especially in the dry season, and underestimates intake by small ruminants (-24%). Alternative assessment methods are proposed either relying on a single standard annual intake per metabolic weight unit for all ruminant species, 73 g/kg LW0.75 per day, or on separate annual intake norms per live weight unit for cattle (18 g/kg LW per day) and small ruminants (34 g/kg LW per day). In both cases, modulations (+/- 12%) of the norm are proposed for use in the wet and dry season.

As impacts of introduced species cascade through trophic levels, they can cause indirect and counter-intuitive effects. To investigate the impact of invasive species at the network scale, we use a generalized food web model, capable of propagating changes through networks with a series of ecologically realistic criteria. Using data from a small British offshore island, we quantify the impacts of four virtual invasive species (an insectivore, a herbivore, a carnivore and an omnivore whose diet is based on a rat) and explore which clusters of species react in similar ways. We find that the predictions for the impacts of invasive species are ecologically plausible, even for large networks robust predictions for the impacts of invasive species can be obtained. Species in the same taxonomic group are similarly impacted by a virtual invasive species. However, interesting differences within a given taxonomic group can occur. The results suggest that some native species may be at risk from a wider range of invasives than previously believed. The implications of these results for ecologists and land managers are discussed., 10 pages, 2 figures, 1 table

Body weight, testes development and serum testosterone, follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels were determined and compared in two groups of peri-pubertal male dromedaries. Daily maximum and minimum ambient temperatures and dry and wet-bulb temperatures were recorded. Temperature-humidity index was calculated. The camels were divided into two equal groups of nine camels each, of comparable body weight: Group (A) received a diet of 13% crude protein and 2.9 MCal metabolizable energy (ME) with added premix, while Group (B) received a non-pelleted diet of alfa-alfa and wheat straw at the ratio of 1:3 giving 12.4% CP and 2.7 MCal ME. Individual feed intake was calculated after 14 days of adaptation. Feed offered and orts were recorded daily throughout the experimental period (24 months). Animals were fed diets containing 1:3 alfa alfa:wheat straw. Blood samples were collected from 5 camels in each group at 15-day intervals during the experimental period. None significant difference in total body weight was found between groups A and B throughout the entire experimental period (p >0.05). Group averages of daily feed intake for the entire period were 5.82 kg in group A and 7.08 kg in group B, respectively (p

Estimating individual feed intake of fish held in groups has long been a challenge precluding precise knowledge of the individual variation of feed efficiency (FE) in fish. In this study, counts of the number of feed pellets (1.63 mg on average) eaten by individual tilapia (Oreochromis niloticus) held in 8 mixed sex groups of 15 fish were measured from video recordings made over a period of 10 days where fish were fed twice daily to achieve compensatory growth after 10 days of fasting. The initial body weight of the fish was 9.77 ± 2.03 g. Accumulated measures of feed intake (FI) over 11 meals were found to achieve 95% repeatability and a high accuracy of estimation of FI. During the FI measurement period, the average fish growth was 12.0 ± 3.6 g, feed intake was 0.99 g day− 1, and feed conversion ratio (FCR) was 0.86 ± 0.20. FI differences accounted for 56% of the observed individual growth variations, and 44% was related to individual variations of FE. On average males grew 24.2% faster than females but consumed 12.1% more feed. Males showed an 11.7% better FCR than females, whereas residual feed intake (RFI) differences were not significant between sexes. FCR and RFI were moderately and significantly correlated (0.58 ± 0.06) but FCR and FI, and body weight gain (BWG) and RFI, were not, highlighting the complex relationships between feed efficiency traits. The approach described here demonstrates a means to accurately investigate FE traits in fish and to assess the potential for their genetic improvement. Statement of relevance Feed efficiency has strong economic and environmental impact.

International audience; Working along forest edges, we aimed to determine how some caterpillars can co-exist with territorially dominant arboreal ants (TDAAs) in tropical Africa. We recorded caterpillars from 22 lepidopteran species living in the presence of five TDAA species. Among the defoliator and/or nectarivorous caterpillars that live on tree foliage, the Pyralidae and Nymphalidae use their silk to protect themselves from ant attacks. The Notodontidae and lycaenid Polyommatinae and Theclinae live in direct contact with ants; the Theclinae even reward ants with abundant secretions from their Newcomer gland. Lichen feeders (lycaenid; Poritiinae), protected by long bristles, also live among ants. Some lycaenid Miletinae caterpillars feed on ant-attended membracids, including in the shelters where the ants attend them; Lachnocnema caterpillars use their forelegs to obtain trophallaxis from their host ants. Caterpillars from other species live inside weaver ant nests. Those of the genus Euliphyra (Miletinae) feed on ant prey and brood and can obtain trophallaxis, while those from an Eberidae species only prey on host ant eggs. Eublemma albifascia (Erebidae) caterpillars use their thoracic legs to obtain trophallaxis and trophic eggs from ants. Through transfer bioassays of last instars, we noted that herbivorous caterpillars living in contact with ants were always accepted by alien conspecific ants; this is likely due to an intrinsic appeasing odor. Yet, caterpillars living in ant shelters or ant nests probably acquire cues from their host colonies because they were considered aliens and killed. We conclude that co-evolution with ants occurred similarly in the Heterocera and Rhopalocera.

L'agriculture de conservation (AC) a été introduite à Madagascar dans l'objectif de maintenir la durabilité des cultures pluviales. L'AC et l'élevage de ruminants doivent être considérés comme des activités complémentaires et synergiques mais des compétitions pour l'utilisation de la biomasse peuvent néanmoins apparaître dans certaines circonstances. En effet, l'AC permet de fournir des ressources fourragères pour l'alimentation des ruminants. En contrepartie les ruminants recyclent une partie de la biomasse ingérée, mais non digérée, sous forme de fumier. Les ruminants permettent ainsi d'améliorer la fertilité du sol via l'apport de fumier. Le recyclage des nutriments au sein d'une exploitation mixte d'agriculture-élevage peut être optimisé en améliorant les techniques de conservation des résidus des cultures et des effluents d'élevage. Cette thèse vise à acquérir des connaissances pour une gestion optimisée des biomasses végétales et animales afin d'améliorer la production agricole. Le principe est de favoriser le recyclage des biomasses végétales et animales en limitant les pertes en nutriments au sein de l'exploitation agricole. Pour cela, trois systèmes de culture pluviale ont été suivis en milieu contrôlé durant trois campagnes (2013 à 2016) : (i) rotation du riz avec du maïs associé à crotalaire en AC, (ii) rotation du riz avec de l'avoine en AC et (iii) rotation du riz avec du maïs associé au haricot en labour. À l'intérieur de chaque système de culture, quatre types de fertilisation ont été comparés : (i) aucune fertilisation, (ii) 5 t ha-1 de fumier conventionnel, (iii) 5 t ha-1 de fumier amélioré et (iv) 5 t ha-1 de fumier conventionnel + fumure minérale. Nous avons installé et suivi également les systèmes de culture ii et iii, et les deux fertilisations ii et iii en milieu paysan, pendant deux campagnes (2013 à 2015). Les rendements en grain de riz sont 27% et 48% supérieurs en utilisant le fumier amélioré ou la fumure minérale, respectivement, par rapport à la situation sans fertilisation. Pour les autres cultures, l'ordre d'importance des rendements en grain ou paille est similaire : fumure minérale > fumier amélioré > fumier conventionnel > sans fertilisation, mais la différence n'est significative que pour le maïs en milieu contrôlé. La production totale en grain (detoutes les cultures de la rotation) est plus élevée avec la rotation riz//maïs associé à la crotalaire et riz//maïs associé au haricot par rapport àla rotation riz//avoine. La production totale en paille de la rotation riz//maïs associé à la crotalaire est toujours significativement importante (10 à 17 t MS ha-1) en comparant à celle des deux autres systèmes de culture, grâce à la forte production de la crotalaire. Les rendements en paille ou en grain en milieu contrôlé et paysan sont similaires. Les racines de l'ensemble des plantes de chaque système de culture étudié permettent de restituer 18%, 27% et 28% du carbone total de toutes les biomasses aériennes et racinaires de la rotation riz//maïs associé à la crotalaire (10,0 t C ha-1 sur 2 ans), riz//avoine (3,1 t C ha-1 sur 2 ans) et riz//maïs associé au haricot (3,6 t C ha-1 sur 2 ans), respectivement. La simulation sur vingt ans du stock en C du sol (horizon 0 à 30 cm) montre que le delta carbone est toujours positif sous la rotation riz//maïs associé à la crotalairequand le stock en C total initial est inférieur à 160 t ha-1. Sous culture de riz//avoine et riz//maïs associé au haricot, le stock en C du sol peut être maintenu à l'équilibre, même en exportant 90% de la biomasse végétale aérienne pour l'alimentation animale, si le stock en C initial est de 60 t C ha-1. À chaque augmentation de 10 t C ha-1 du stock en C initial, les biomasses des rotations riz//avoine et riz//maïs associé au haricot exportées doivent être réduites respectivement de 17% et de 13% pour maintenir le stock en C initial. Ainsi, le delta carbone des rotations riz//avoine et riz//maïs associé au haricot devient négatif si les stocks en C de départ sont respectivement supérieurs à 110 et 130 t C ha-1. Pour ce qui concerne la restitution d'azote au sol, elle est également plus importante avec la rotation riz//maïs associé à la crotalaire (164 kg N ha-1 an-1) en comparant avec les deux autres rotations (de l'ordre de 45 kg N ha-1 an-1). En contrepartie, la rotation riz//avoine permet une production importante de lait (jusqu'à 3 640 l ha-1 an-1) par rapport aux autres rotations, riz//maïs associé au haricot (19% inférieur) et riz//maïs associé à la crotalaire (41% inférieur). En revanche, la rotation riz//maïs associé au haricot permet une production plus importante en grain plus riche en protéine par rapport aux deux autres rotations. Cependant, en tenant compte de toutes les productions (lait, grain, azote resitué au sol), la rotation riz//maïs associé à la crotalaire est la plus intéressante économiquement, avec un gain de 330 à 430 kAr ha-1 an-1 par rapport à la rotation riz//avoine, et de 60 à 620 kAr ha-1 an-1 par rapport à la rotation riz//maïs associé au haricot, suivant le taux d'exportation de la biomasse végétale consommable par les animaux. Pour chaque système de culture, la vente du lait produit, en valorisantla biomasse végétale comme fourrage, permet d'acheter une forte quantité de fumier et des engrais minéraux pour améliorer la fertilité du sol afin d'accroître les productions en grain dont celles du riz pour l'alimentation humaine. Le choix du système de culture utilisé dépendra, au final, de l'objectif de chaque paysan et de la taille de son exploitation.

Improving feed efficiency (FE) is key to reducing production costs in aquaculture and to achieving sustainability for the aquaculture industry. Feed costs account for 30-70% of total production costs in aquaculture; much work has been done on nutritional and husbandry approaches to improve FE but only a limited amount of research has been devoted to using genetics, despite its potential. This paper reviews past work to improve FE in fish using selective breeding and assess future directions. Direct selection on FE traits requires methods to measure individual feed consumption and estimate FE efficiently and accurately. This is particularly difficult to do in fish because of the environment in which they live. Many of the published studies on FE were found to be inaccurate because of methodological problems. The relatively low heritability estimates of FE traits in fish published to date are probably partly as a result of inaccurate measurements of feed intake. Improving ways to measure the individual feed intake with high accuracy will be critical to the successful application of genetics to improving FE. Indirect selection criteria that could be used to improve FE (including growth after starvation/refeeding, body composition, neuropeptides or hormone levels) are discussed. Promising approaches to measuring feed intake accurately that may enable these studies to be undertaken are identified. More work using these will be needed prior to assessing the practicality of the introduction of direct or indirect traits for FE in fish genetic improvement programmes.

Selenium deficiency is widely described in livestock from the Arabian Peninsula, notably in the camel, and selenium supplementation is based on cattle or horse requirements, usually with sodium selenite product. In order to test the effect of organic Se supplementation vs inorganic Se, 24 pregnant camels were subjected to 3 treatment groups starting one month before delivery (control without Se, non-organic bolus, organic Se). Blood, milk and feces samples were collected from one month before delivery to 3 months of lactation. At delivery, the organic group had a significant higher Se concentration (P < 0.01) in serum (8.21± 1.38 lg/100 mL) and in colostrum (7.27 ±2.89 lg/100 mL) than in inorganic group (3.90 ±0.68 and 3.72 ±0.71, respectively) and than in control group (5.45 ± 2.38 and 2.70 ± 0.66, respectively). In calf serum, the Se concentration was significantly higher (P < 0.001) in the two supplemented groups (6.32 ± 2.81 and 5.99 ± 3.31 lg/100 mL in organic and inorganic groups, respectively) than in control (3.42 ±1.41 lg/100 mL). The Se in mother serum decreased after parturition but was highly correlated to Se serum in calf and to Se fecal excretion. Se in milk was lower than in colostrum in all groups (P < 0.01). Treatments had no significant effect on somatic cell count. This study revealed that organic supplementation in camel appeared more efficient. (Resume d'auteur)

Tropical highland blackberries are a rich source of ellagitannins (ETs), which are metabolized by gut microbiota to yield urolithin, a potentially bioactive compound excreted in urine up to 7 days after ingestion. Following the ingestion of 250 mL of tropical highland blackberry juice, a spot of urine from 26 volunteers collected at 51 ± 4 h was analyzed for urolithin A and B main derivatives (aglycones and glucuronated forms). Three main groups, “no or low urolithin excreters,” “predominantly UA derivatives excreters” and “predominantly UB derivatives excreters,” were observed. These categories were also unambiguously observed from 9 individuals following the total excretion of ETs' main metabolites over a 4-day period after ingesting one shot of blackberry juice. Although relatively high inter- and intra-individual variabilities were observed, individuals preserved their status during different intervention periods with different amounts of ETs ingested. Accurate UPLC-DAD/ESI-Q-TOF/MS2 allowed the tentative assignment of an identity to 15 other ET metabolites in urine, but profiling did not allow the discrimination of any other compounds aside from UA or UB derivatives. The results highlight the importance of the interaction of gut microbiota composition and the host endogenous excretery system, which may play a major role in the observed inter-individual variability.

This study evaluates the antioxidant and anti-inflammatory activities in a polyphenol extract from blackberries. The antioxidant activity measured via oxygen radical absorbance capacity (ORAC) was higher for the blackberry extract (4339 ± 144 μM TE/g) than for quercetin and ellagic acid. The blackberry phenolic compounds protected liposomes and liver homogenates against lipid peroxidation; in both models, the antioxidant activity (IC50 = 7.0 ± 0.5 and 20.3 ± 4.2 μg/mL, respectively) was greater than that found with Trolox. The extract inhibited superoxide production by NADPH oxidase in THP-1 cells and nitrite production in J774A.1 cells stimulated with LPS+IFNγ, with nitrite production decreasing after 4 h of incubation with the extract, mainly through a strong scavenging activity. However, 24 h of treatment reduced the amount of nitrites (IC50 = 45.6 ± 1.2 μg/mL) because of a down-regulation of iNOS protein expression, as demonstrated by Western blotting. The inhibitory activities found in blackberry phenols suggest a potential beneficial effect against oxidative stress and inflammatory processes. UCR::Vicerrectoría de Docencia::Salud::Facultad de Medicina::Escuela de Medicina UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro Nacional de Ciencia y Tecnología de Alimentos (CITA)

In Citrus species chromosome doubling naturally occurs in somatic embryos and doubled diploid plants often show better adaptation to adverse environmental condition. To understand the molecular determinants of stress acclimation, we examined the response to water deficit in diploid (2×VL) and doubled diploid (4×VL) seedlings of Volkamer lemon (Citrus limonia Osb.) assessing the profile of constitutive volatile organic compound (VOC) in control and stressed conditions. Physiological parameters and leaf volatile compound profiles were measured during water deficit and 24 h after rehydration of plants to field capacity. Net photosynthesis and stomatal conductance were reduced in water stressed leaves, with no significant differences between 2×VL and 4×VL plants. Malondialdehyde concentration, a marker of lipid peroxidation of cellular membranes, was significantly more higher in stressed 2×VL leaves than in 4×VL. The blend of constitutive VOC was different in control leaves being oxygenated monoterpenoids more abundant in 2×VL leaves, and monoterpenoids more abundant in 4×VL leaves. Water deficit did not stimulate biosynthesis of terpenoids, whereas accumulation of trans-2 hexenal, a green leaf volatile (GLV) synthesized after membrane denaturation, was observed in stressed leaves of 2×VL leaves, but not in 4×VL leaves. Semiquantitative PCR showed an increase of the expression of HPL, the gene encoding for hydroperoxidase lyase which catalyzes 2-hexenal formation, only in 2×VL plants. The expression of the putative dehydration transcription factor DREB2A was also observed only in 2×VL water stressed plants. This work shows that level of ploidy may alter constitutive content of GLV by Citrus, therefore likely affecting plants capacity of protection and interaction with other organisms. Whereas diploid and double diploid plants showed similar physiological responses to water deficit, a biochemical marker indicated that membranes of double diploid leaves were more resistant to the stress. These results provide intriguing insights into the regulation of terpenoids and oxylipins pathways as a function of polyploidization in a non-model plant species.

Cette étude, qui avait pour objectif général d'estimer la variabilité de la digestibilité et des émissions potentielles de méthane des régimes des ruminants au cours de l'année sur parcours sahélien, a été réalisée dans la zone du Ferlo (Sénégal) au niveau des sites de Dahra et Niassanté. Vingt-quatre échantillons de régimes et de fèces collectés et traités pour les besoins des analyses SPIR à Montpellier. La digestibilité et l'estimation de la production de méthane ont été calculées à partir des équations de prédiction. Les résultats obtenus montrent que les régimes sont constitués en moyenne de paille, de graminées et de légumineuses. La digestibilité est en moyenne de 51,26 ± 1,35% et 52,62 ± 3,28% pour les deux sites. La production de gaz méthane est plus élevée en fin d'hivernage et début saison sèche. Elle est à environ 161 litres/jour pour le mois d'octobre et de 33 litres/jour pour le mois de juillet, avec une moyenne de 75 litres/jour/animal. La production de méthane par les bovins est significativement affectée par la période de l'année et la quantité de matière sèche ingérée. Elle est négativement affectée par la digestibilité de la matière organique des régimes ingérés.

Flows of carbon and nitrogen in a natural phytoplankton assemblage from the plume of the Scheldt estuary were followed during and after a light-induced bloom by measuring changes in concentrations and stable isotope ratios in mesocosms after addition of 13C (as bicarbonate or glucose) and 15N (as ammonium or nitrate). Addition of 13C-bicarbonate showed a strong coupling between algal primary production and bacterial secondary production, while addition of 13C-glucose revealed bacteria as a carbon source for eukaryotes. Tracing the 13C into mesozooplankton, we identified selective grazing on algae during the phytoplankton bloom, transfer of carbon from bacteria to mesozooplankton and opportunistic feeding strategies after the bloom. Nitrogen labeling confirmed carbon labeling findings, identified bacteria rather than mesozooplankton as ammonium regenerators and allowed quantification of nitrification. (Resume d'auteur)

bInra, eaSM, domaine du Magneraud, Bp 52, 17700 Surgeres, f rance c Inra, unite de recherches a vicoles, 37380 nouzilly, f rance d cIrad, Qualisud, 73 rue Jean-f rancois Breton, ta B-40/16, 34398 Montpellier cedex 05, f rance The potential of near infrared (NIR) spectroscopy for the determination of the chemical composition of poultry excreta was investigated, within the framework of studies on heritability of digestive efficiency in broilers. Samples in the calibration and validation databases (DB1 and DB2) corresponded to animals fed with a similar wheat-based diet. A second validation study was performed on excreta samples from animals fed more variable diets, including peas and maize (DB3). Excreta samples were freeze-dried and ground. Near infrared reflectance spectra were taken on a monochromator spectrometer between 400 nm and 2500 nm. Samples were analysed for mineral matter (MM), gross energy (GE), starch, crude fat (CFAT), total nitrogen (NTOT), uric acid nitrogen (NUA) and protein nitrogen estimated directly (PNTERP) or by difference between NTOT and NUA (PNUA). Depending on the parameters studied, 250 to 700 samples were analysed by reference methods. The standard error of cross-validation (SECV) and R² of calibrations were: 0.60% and 0.96 for MM, 166 kJ kg –1 and 0.99 for GE, 0.59% and 1.00 for starch, 0.44% and 0.99 for CFAT, 0.25% and 0.89 for NTOT and 0.22% and 0.97 for NUA, respectively. Calibration for PNTERP (SECV = 0.07%; R²=0.98) was much more precise than PNUA (SECV = 0.21%, R² = 0.85). Validation carried out on databases DB2 and DB3 resulted in standard errors of prediction (on DB2) and extrapolation (on DB3) generally higher than SECV, while remaining relatively precise with prediction r² values from 0.83 to 0.99 and extrapolation r² from 0.86 to 0.98, with the exception of PNUA for which r² was 0.22 and 0.64, respectively. For some parameters, the lower validation performance was due to biases, particularly in the case CFAT and NUA for prediction and MM, GE and NUA for extrapolation. Global calibrations made with DB1+DB2+DB3 were more precise (GE, NTOT) or equally precise (all other parameters) than with DB1 alone. These results confirmed the potential precision of calibrations for the major organic compounds in poultry excreta and suggested that their use could be extended to excreta issued from a wider range of diets without losing precision.

Eight young female camels shared in four groups of two 2 years received a basal diet enriched respectively with 0, 2, 4, and 8 mg selenium under sodium selenite form for 64 days. Feed intake was assessed daily; blood samples were taken on weekly basis. One camel from each group was killed at the end of the experiment. Se concentration in serum was increased significantly in the supplemented groups with an average of 176.3 +/- 18.0 ng/mL in the control group, 382.7 +/- 107.6 in the group receiving 2 mg Se, 519.8 +/- 168.4 in the group receiving 4 mg Se, and 533.4 +/- 158.6 in the group receiving 8 mg Se daily. For glutathione peroxidase (GSH-Px) activity, the control group (51.0 IU/g Hb) and the group receiving 2 mg (50.5 IU/g Hb) were significantly different than groups receiving 4 and 8 mg (respectively, 65.9 and 76.1 IU/g Hb). No significant variation occurred for vitamin E (mean, 0.56 +/- 0.23 ng/mL). Significant correlation between serum Se and GSH-Px was reported. Kidney was the richest organ in selenium followed by lung, spleen, and liver, but the increase in supplemented groups was more marked in liver and kidney. The hair seemed to be the best indicator of selenium intake in camel.

L'objectif de notre étude était, à partir d'une base de données issue d'essais de digestibilité fécale réalisés chez le poulet standard, de mieux comprendre les facteurs de variation de la digestibilité (CUD) de l'amidon, des protéines, des matières grasses et de l'énergie des aliments. Cinq essais (51 aliments) ont été mis en place avec plusieurs modalités : le profil des matières premières (céréales, matières riches en protéines, huiles), le niveau énergétique des aliments, l'âge et le sexe des poulets. Le CUDa de l'azote d'un aliment à base de blé/soja a diminué de 4 % (P 55 %), le CUD de l'amidon a tendance à diminuer et montre une variabilité individuelle beaucoup plus importante. L'âge des poulets ressort comme un facteur important, les poulets les plus jeunes ayant mieux digéré l'amidon. La teneur en amidon des fientes explique le CUD de l'amidon de 86 à 99 % selon les essais. Le CUD des matières grasses a diminué en présence d'huiles acides et de colza en comparaison à l'huile de soja. En revanche, il a augmenté avec l'âge des poulets surtout en présence d'aliments à faible niveau énergétique. Du fait des interactions entre les différents nutriments, le CUD de l'énergie est plus difficile à analyser. Pour tous types d'aliments confondus, le CUD de l'énergie est fortement corrélé avec le CUD des protéines (R=0,79 ; P

L'intérêt de la Spectrométrie Proche InfraRouge (SPIR) pour estimer rapidement la digestibilité des aliments a été démontré pour des poulets élevés dans des conditions expérimentales. Ces étalonnages nécessitent par ailleurs une étape de séchage ou de lyophilisation au laboratoire. Dans l'objectif de rendre ces mesures applicables sur le terrain pour un pilotage plus fin de l'alimentation, une étude de faisabilité a été réalisée en élevages de poulets de chair. La prise de spectre des échantillons a été effectuée en parallèle sur fientes séchées et sur fientes fraîches, avec un appareil portatif. Une première phase a permis de comparer les mesures obtenues classiquement par bilan digestif en station expérimentale, aux prédictions obtenues par SPIR en conditions d'élevage. Les prédictions de digestibilité de l'amidon, de l'azote et de la matière grasse ont été cohérentes entre les deux méthodes. Dans une seconde phase, des prédictions de digestibilité par SPIR ont été effectuées sur 32 prélèvements réalisés en élevage. Les valeurs de digestibilité prédites par SPIR ont été assez variables. Elles ont permis de différencier les phases d'élevage pour la digestibilité de l'amidon et de l'énergie, mais pas pour la matière grasse et l'azote. Avec les fientes fraîches, la qualité des mesures prédites est inférieure à celle obtenue sur fientes séchées. En conclusion, ces résultats préliminaires sont encourageants, mais ont montré la nécessité d'enrichir la base d'étalonnage avec une grande variété d'échantillons issus du terrain.

The date production in arid countries like Saudi Arabia includes a part of discarded dates for human consumption. These discarded dates could be used as supplementary feeding for livestock. In trials carried out in a camel farm, date blocks were prepared which composed of 50% dates, 40% wheat bran, 5% urea to increase nitrogen level and 5% cement as binding material. Two groups of 7 camels each 2-3 y old received basal diet composed of alfalfa (2kg/100kg LW) and 1 kg of supplementary feed, i.e. market concentrated for control group and date blocks for treated group. The duration of the trial was 4 months. Blood sampling was done every fortnight for determining urea, glucose, AST and ALT and the growth of camels was monitored by regular weighing at sampling time. Weighing and blood sampling were done in the morning before feed distribution. The intake was 1.94 ± 0.19 and 1.85 ± 0.19 kg/100kg LW in control and treated group respectively, and the mean daily weight gain was 407 and 305g/day, respectively, corresponding to a weight gain of 0.43 kg in control group vs 0.32 kg in treated group, i.e. a consumption index of 2.33 and 3.11 kg concentrates/kg weight gain, respectively. There was no significant difference in the blood parameters. In conclusion, date blocks could be safely used for supplementary feeding of young camels as partial substitution for the regular feed.

L'efficacité digestive influe fortement sur l'excrétion et par conséquent l'impact environnemental de la production de poulet de chair. Nous avons recherché les zones du génome contrôlant des caractéristiques importantes des rejets sur un croisement F2 entre deux lignées sélectionnées de façon divergente sur l'efficacité digestive. Au total, 865 animaux ont été mesurés pour les quantités brutes de fientes fraîches et sèches (PFF, PFS) et leur rapport à la consommation alimentaire de fientes fraîches et sèches (PFFC, PFSC), le contenu en eau des fientes (EAU), le rapport entre azote et phosphore dans les fientes (N/P), le pH des fientes, du contenu du gésier et du contenu du jéjunum (PHF, PHG, PHJ). L'ensemble des animaux (F0, F1, F2) a été génotypé avec 6000 marqueurs SNP couvrant 28 autosomes, un groupe de liaison non assigné et le chromosome Z. Au total, 11 QTLs ont été identifiés pour : PFS (GGA19, GGA26), PFFC (GGA8), PFSC (GGA16), N/P (GGA11, GGA26), EAU (GGA28), PHG (GGA2, GGA16, GGA27) et PHJ (GGA19). Le QTL du pH du gésier sur le chromosome 2 est le plus significatif (P=0,15 au niveau du génome), les autres QTLs n'étant significatifs qu'au niveau du chromosome. Sur les chromosomes 16 et 27, ces QTLs co-localisent avec des QTLs d'efficacité digestive. Sur les chromosomes 8, 16 et 26, ces QTLs co-localisent avec des QTLs de longueur relative de l'intestin. Des travaux sont actuellement en cours pour confronter les données d'expression de gènes sur les tissus du tractus gastro-intestinal et les données de génomique positionnelle présentées ici afin de suggérer des gènes candidats expliquant ces QTLs.

A meta-analysis was conducted (i) to evaluate broiler response to partial or total substitution of corn by sorghum and millet and (ii) to determine the effect of soybean meal replacement by cottonseed meal in broiler diet. The database included 190 treatments from 29 experiments published from 1990 to 2013. Bird responses to an experimental diet were calculated relative to the control (Experimental - Control), and were submitted to mixed-effect models. Results showed that diets containing millet led to similar performance as the corn-based ones for all parameters, whereas sorghum-based diets decreased growth performance. No major effect of the level of substitution was observed with millet or cottonseed meal. No effect of the level of substitution of sorghum on feed intake was found; however, growth performance decreased when the level of substitution of corn by sorghum increased. Cottonseed meal was substituted to soybean meal up to 40% and found to increase feed intake while reducing growth performance. Young birds were not more sensitive to these ingredients than older birds since there was no negative effect of these ingredients on performance in the starter phase. Results obtained for sorghum pointed out the necessity to find technological improvements that will increase the utilization of these feedstuffs in broiler diet. An additional work is scheduled to validate these statistical results in vivo and to evaluate the interactions induced with the simultaneous inclusions of sorghum, millet and cottonseed meal in broiler feeding.

Selective grazing by ruminant livestock and other herbivores causes difficulties in measuring or estimating the chemical composition and functional properties (digestibility and intake) of the diets of free grazers. New methodologies using faecal near infrared reflection spectroscopy (NIRS) offers scope to estimate diet quality in grazing animals once suitable calibration equations have been developed. This study was conducted to determine the potential of faecal NIRS to predict crude protein (CP), neutral detergent fibre (NDF), acid detergent fibre (ADF) and organic matter digestibility (OMD) of the diet of cattle grazing tropical grass pastures as well as organic matter intake (OMI). Reference data and faecal spectra were measured from a pen experiment in which 11 Creole steers (were individually housed and fed diets of fresh grass harvested from irrigated plots of (i) Digitaria decumbens and (ii) Dichanthium spp. The experiment ran for 70 days (14 days adaptation, 56 days measurement) and variation in diet quality was achieved by varying the age of grass regrowth after an initial mowing. Grass samples and faecal samples were bulked within each week of the measurement period within steer. The 88 dried and milled faecal samples (11 steers × 8 weeks) were scanned in a NIR Systems 5000 monochromator. Faecal spectra and reference data were used to calibrate and cross validate equations for predicting the various parameters using the Modified Partial Least Squares (MPLS) procedure. Derived standard errors of calibration (SEC) and coefficients of determination (R2) were 0.33 and 0.98% for dietary CP, 0.96% and 0.88 for NDF, 0.81% and 0.89 for ADF, 0.021 and 0.72 for OMD, and 4.62 g/kg of (body weight)0.75 and 0.61 for OMI. These values compared favourably with published faecal NIRS reports, where available for CP and OMD, and also with many published forage NIRS results and confirmed the potential of faecal NIRS as a technology for reliably predicting the chemical composition and functional properties of diets in grazing cattle. © 2004 Elsevier B.V. All rights reserved.

The negative relationship between intake and digestibility of an unchanging diet has been widely described. The review of the different processes of ruminai digestion shows that the main cause of the variation in digestibility is the retention time of particles in the rumen. However, most experiments have been carried out at levels of intake higher than maintenance. For this reason, a special attention is paid to experiments carried out at low levels of intake. In these conditions, the response of digestibility to a decrease in intake is variable: it can increase, be stable or decrease. Up till now, it has not been possible to determine the animal or nutritional factors which influence the way of variation, and especially the unexpected decrease in digestibility. However, it has been clearly shown that these decreases are not due to an insufficient retention time of particles in the rumen, or to an insufficient reduction of particle size. Differences in microbial activity have not been exhibited by in situ measurements. It is hypothesised that a reduction of bacterial growth, or of the expression of microbial degradation potential occurs at very low intakes, but mechanisms are still not elucidated. The decrease in weight and oxygen uptake by the digestive tract contributes to the adaptation of animals maintenance requirements. At short term, the proportion of metabolisable energy intake which is recovered in the portal vein remains unchanged when animals are underfed but the supply of absorbable amino acids (AAs) cannot keep up with the gut requirements. The consequences of underfeeding on nutrition and absorption do not differ between small ruminants and cattle. © 2003 Elsevier Science B.V. All rights reserved.

Consumption of dietary ellagitannins (ETs) has been associated with different health benefits. Nonetheless, ETs are not bioavailable as such and are metabolized in vivo. They are partially converted into ellagic acid (EA) in the upper gastrointestinal (GI) tract, but this first metabolite is also poorly bioavailable. In the lower GI tract, EA and residual ETs are metabolized by gut microbiota to produce urolithins, which, together with their conjugate relatives, persist at relatively high concentrations in plasma and urine for days after ingestion of dietary ETs. Thus, ETs and EA may exert local health benefits on the GI tract but systemic health benefits are more likely to result from urolithins. Cellular models suggest that, at physiological concentration, urolithins are active against chronic degenerative diseases. Health benefits have been proven in animal models and during clinical studies. Even so, the crucial involvement of gut microbiota in ET bioconversion induces important variability of physiological response among humans, giving rise to the concept of high and low urolithin producers. This variability among consumers in obtaining potential health benefits from dietary ETs raises new challenges for the functional food industry. Different research perspectives are discussed to tackle this significant issue for nutritionists, food technologists, and consumers.

International audience; beta,beta-Carotene 15-15 ' mono-oxygenase 1 (BCMO1) is a key enzyme in vitamin A (VitA) metabolism in mammals. Dietary compounds, such as carotenoids and polyphenols, were reported to influence BCMO1 activity. The aim of this study was to evaluate the effect of hesperidin (Hes), on the VitA bioefficacy of beta-carotene (Bc) from orange-fleshed sweet potato, using Mongolian gerbils, focussing on BCMO1 activity. Gerbils (n = 50) depleted in VitA were divided into five groups fed with basal diet containing 3% white-or orange-fleshed sweet potatoes supplemented or not with Hes. Liver BCMO1 activity was low, with no significant differences between groups. Interestingly, intestinal mucosal BCMO1 activity was significantly higher in the gerbils fed without Bc or VitA than those fed with a VitA/Bc-supplemented diet. Finally, our results show that, under a low VitA status, Hes dramatically stimulated intestinal BCMO1 activity, an effect that could possibly be related to its action as an agonist of PPAR gamma.

A meta-analysis was performed to investigate bird's response on some selected alternative feed ingredients: millet, sorghum and cottonseed meal. The database used contained 186 treatments from 25 different experiments published from 1990 to 2013. A 1-way ANOVA was performed to determine the difference induced by each ingredient on average daily feed intake, body weight gain and feed conversion ratio, compared to control diets. Besides, mixed effects models were developed to test the impact of the level of substitution on all parameters during starter and growing phases. Results indicated an effect of the type of feed ingredient on feed intake and growth performance with better efficiency obtained in millet. No linear relationship was established between level of substitution and variables of interest for all ingredients (R²=0). Additionally, the root mean square error (RMSE) determined for each subset of data demonstrated that observations of this study are practically predictable. Therefore, it is in perspective of this work to predict bird's response to those ingredients nutrients supply. This meta-analytic approach provides significant quantitative knowledge to utilize those ingredients at different levels without any detrimental effect in broilers. Regarding the anti-nutritional factors content of some of these ingredients, it would be interesting to further suggest improvements leading to an increasing utilization of these alternative feedstuffs in poultry.