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UNLABELLED: Very little is known about the feeding of naupliar and juvenile life stages of omnivorous fairy shrimps (Crustacea: Anostraca). Here, we aim to reveal whether the fairy shrimp Branchinecta orientalis is an ontogenetic omnivore and at which age and ontogenetic stage they gain the ability to feed on zooplankton. We assess how food uptake rates change with age until reaching maturity by providing algae (pico- and nanoplanktonic unicellular algae) and zooplankton (rotifers and copepod nauplii) as food in individual experiments. We found that the fairy shrimp B. orientalis started to feed on both types of algal prey immediately after hatching. Nanoplanktonic algae likely represented the most important food source until reaching maturity. Moreover, fairy shrimps started to feed on zooplankton already when they were 7 days old. Slow-moving rotifers gradually gained importance in the fairy shrimp diet with time. Our results reveal an ontogenetic change in the prey spectrum of fairy shrimp. The systematic shift towards omnivory likely affects both phyto- and zooplankton community composition, possibly contributing to temporal changes in food web dynamics in fairy shrimp habitats, and temporary ponds, which may warrant more detailed investigations in future studies. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10750-022-05132-z. ispartof: HYDROBIOLOGIA vol:850 issue:4 pages:901-909 ispartof: location:Netherlands status: published

This study aimed to develop a tool to detect mildly lame cows by combining already existing data from sensors, AMSs, and routinely recorded animal and farm data. For this purpose, ten dairy farms were visited every 30–42 days from January 2020 to May 2021. Locomotion scores (LCS, from one for nonlame to five for severely lame) and body condition scores (BCS) were assessed at each visit, resulting in a total of 594 recorded animals. A questionnaire about farm management and husbandry was completed for the inclusion of potential risk factors. A lameness incidence risk (LCS ≥ 2) was calculated and varied widely between farms with a range from 27.07 to 65.52%. Moreover, the impact of lameness on the derived sensor parameters was inspected and showed no significant impact of lameness on total rumination time. Behavioral patterns for eating, low activity, and medium activity differed significantly in lame cows compared to nonlame cows. Finally, random forest models for lameness detection were fit by including different combinations of influencing variables. The results of these models were compared according to accuracy, sensitivity, and specificity. The best performing model achieved an accuracy of 0.75 with a sensitivity of 0.72 and specificity of 0.78. These approaches with routinely available data and sensor data can deliver promising results for early lameness detection in dairy cattle. While experimental automated lameness detection systems have achieved improved predictive results, the benefit of this presented approach is that it uses results from existing, routinely recorded, and therefore widely available data.

Different species-specific traits of woody plant species, feeding preferences of herbivores together with resulting effects on plant competition are expected to translate into different plant community structures and expressions of biodiversity. We studied the diversity of woody plant species (trees and shrubs) and structural diversity of forest trees, using a 30-year and an 18-year dataset of ungulate exclosure-control plot pairs in a mixed alpine forest community in Austria. We surveyed the tallest individuals per tree species and plot and analyzed the collective of top-height individuals per plot pair. Incidence data for exclosure and control plots were aggregated. Comparing species diversity and diversity of height classes on the plots throughout time, we calculated diversity profiles based on Hill numbers. Diversity of top height individuals and structural diversity, expressed by height classes, were two diversity aspects that differed between exclosures and control plots. Other diversity estimates of woody plant species showed huge variation without significant differences between plots. Height growth was significantly suppressed by ungulate herbivory. Effects of ungulate herbivores in forest ecosystems are highly complex and context-dependent and thus not reducible to simple top-down forces. Long-term surveys provide data that reflect “ultimate” effects of herbivory interacting with other drivers of community dynamics.

Reproduction induces increased food intake across females of many animal species1–4, providing a physiologically relevant paradigm for the exploration of appetite regulation. Here, by examining the diversity of enteric neurons in Drosophila melanogaster, we identify a key role for gut-innervating neurons with sex- and reproductive state-specific activity in sustaining the increased food intake of mothers during reproduction. Steroid and enteroendocrine hormones functionally remodel these neurons, which leads to the release of their neuropeptide onto the muscles of the crop—a stomach-like organ—after mating. Neuropeptide release changes the dynamics of crop enlargement, resulting in increased food intake, and preventing the post-mating remodelling of enteric neurons reduces both reproductive hyperphagia and reproductive fitness. The plasticity of enteric neurons is therefore key to reproductive success. Our findings provide a mechanism to attain the positive energy balance that sustains gestation, dysregulation of which could contribute to infertility or weight gain. A multi-organ circuit is activated in female flies after mating, leading to changes in enteric neurons that increase food intake.

Ruminant production is characterised by a large diversity in husbandry systems and management practices that can influence the animals' welfare. For example, housing conditions are important. In outdoor rearing systems, climate changes can provoke thermal stress and health problems. Indoors, factors such as freedom of movement and type of lying surface are essential for animal comfort and health. A feeding regimen that is not adapted to biological needs can lead to metabolic disturbances and behavioural abnormalities. Specific management practices interfering with the social structure of a herd can also influence the animals' welfare. For example, repeated changes in group composition will lead to repeated stress with possible consequences on the animals' health and performance. Procedures such as castration, dehorning and caesareans seem to have an intense but short-term impact on the animal. Finally, the impact of the human-animal relationship on the ruminants' welfare seems of increasing importance, since there is a tendency towards a higher number of animals per stockperson and less time spent per animal. In conclusion, for ruminant production, numerous parameters, linked mostly to husbandry practices and the living environment (i.e. management and resources), can influence the welfare of the animals. Future research should focus on the impact of these practices and conditions with the aim of developing alternatives., L’élevage des ruminants est caractérisé par une diversité importante de conduites et de pratiques ayant un impact sur le bien-être des animaux. En plein air, les animaux peuvent être exposés à des variations climatiques. En bâtiment, la liberté des mouvements et la qualité de l’aire de couchage sont des facteurs déterminants du confort ressenti par l’animal et de son état sanitaire. Une alimentation inadaptée aux besoins physiologiques, peut provoquer des perturbations métaboliques ou des déviations comportementales. Les modifications des groupes sociaux sont également potentiellement néfastes. Par exemple, des remaniements fréquents de la composition d’un groupe conduisent à un stress et une dégradation de l’état sanitaire et des performances zootechniques. Les interventions comme la castration, l’écornage ou la césarienne, semblent avoir un impact d’une durée limitée sur l’animal. Enfin, l’importance de la relation homme – animal sur le bien-être des ruminants semble accrue du fait de la tendance à une augmentation du nombre d’animaux par soigneur et une diminution du temps passé par animal. En conclusion, une multitude de facteurs, correspondant majoritairement aux conditions d’élevage et aux interventions zootechniques, peut influencer le bien-être des ruminants. Les recherches dans ce domaine doivent s’orienter sur l’impact des pratiques ainsi que les alternatives à développer.

Social information use is well documented across the animal kingdom, but how it influences ecological and evolutionary processes is only just beginning to be investigated. Here we evaluate how social transmission may influence species interactions and potentially change or create novel selection pressures by focusing on predator-prey interactions, one of the best studied examples of species coevolution. There is extensive research into how prey can use social information to avoid predators, but little synthesis of how social transmission among predators can influence the outcome of different stages of predation. Here we review evidence that predators use social information during 1) encounter, 2) detection, 3) identification, 4) approach, 5) subjugation and 6) consumption. We use this predation sequence framework to evaluate the implications of social information use on current theoretical predictions about predator-prey dynamics, and find that social transmission has the potential to alter selection pressures for prey defences at each predation stage. This suggests that considering social interactions can help answer open questions about species coevolution, and also predict how populations and communities respond to rapid human-induced changes in the environment.

We hypothesized that cows with SCK (blood BHB over >1.2 mmol/L) diagnosed within the first 30 days of calving can be predicted by changes in rumination and activity behavioral parameters in the period before calving and indeed subsequently. A total of 45 cows were randomly selected from 60 dry cows from at least 40 days before calving. All the cows were fitted with RuniWatch sensors monitoring both intake behaviors (faceband) and general movement and activity behavior (pedometer) (RWS-ITIN + HOCH, Switzerland). Following an adaptation period of 10 days, rumination, eating, and activity parameters were monitored for 30 days before calving and 30 days after calving. Considering the design of the study, we divided the data of cows into three stages for statistical evaluation: (1) the last thirty days before calving (from day −30 to −1 of the study); (2) day of calving; and (3) the first thirty days after calving (from day 1 to 30 of the study). We found that before calving, those cows with a higher risk of having SCK diagnosed after calving had lower rumination time, eating time, drinking gulps, bolus, chews per min, chews per bolus, downtime, maximal temperature, and activity change. On the calving day, in cows with higher risk of SCK after calving, we found lower rumination time, eating time, chews per min, chews per bolus, uptime, downtime, minimal temperature, other chews, eating chews, drinking time, drinking gulps, activity, average temperature, maximal temperature, activity change, rumination chews, and eating chews. After calving in cows with SCK, we found lower rumination time, eating time 1, eating time 2, bolus, chews per bolus, uptime, downtime, minimal temperature, maximal temperature, rumination chews, and eating chews. Moreover, after calving we found higher drinking gulps, drinking time, activity, activity change, average temperature, other chews, and eating chews in cows with SCK. From a practical point of view, we recommend that by tracking changes in rumination and activity behavior parameters registered with RuniWatch sensors (such as rumination time, eating time, drinking time, drinking gulps, bolus, chews per minute, chews per bolus, downtime, maximal temperature, and activity change) before, during, and after calving, we can identify cows with a higher risk of SCK in the herd.

© 2018 Association for the Sciences of Limnology and Oceanography How grazer selectivity regulates the primary producer community is a core topic in ecology. Yet, the role of zooplankton grazing selection on phytoplankton dynamics is poorly understood. Few studies have compared the effect of grazers with contrasting selectivity on mixed phytoplankton prey, and none over multiple phytoplankton generations. We tested the hypothesis that a selectively grazing copepod (Eudiaptomus gracilis) would facilitate the dominance of a toxic cyanobacterium (Microcystis aeruginosa) by grazing on a competing eukaryotic microalga (Cryptomonas pyrenoidifera), while a generalist cladoceran (Daphnia magna) would have no effect on the dominance of cyanobacteria in 4-d laboratory cocultures. Experiments started with a ninefold initial dominance of Cryptomonas over Microcystis by biomass. Each grazer type was added to cocultured phytoplankton and the abundance of phytoplankton was compared to no-grazer controls. As predicted, Daphnia had no effect on the relative abundance of its prey and the copepod facilitated Microcystis dominance, although the strength of facilitation slightly declined with time. As the copepod reduced mostly the biomass of the edible algae, it pushed the system toward the dominance of toxic prey, which likely reduced the efficiency of selective grazing on the last day. Hence, while the selective grazer promoted cyanobacterial dominance, the effect may be weaker than predicted from extrapolating grazing rates obtained from short-term (i.e., hourly) assays. Overall, predicting the role of zooplankton selectivity on phytoplankton dynamics—especially harmful algal blooms—would benefit from accounting for fluctuations in grazer effects due to shifting abundance and growth of each prey over time. ispartof: LIMNOLOGY AND OCEANOGRAPHY vol:64 issue:3 pages:1214-1227 status: published

Mosquito-borne pathogens have spread throughout tropical regions of the Western Hemisphere causing increased burden of disease in the region. Outbreaks of dengue fever, yellow fever, chikungunya, West Nile, and Zika have occurred over the past several years. Mosquito blood-feeding patterns need to be assayed to assist in determining which vertebrates could act as hosts of these mosquito-borne pathogens and which mosquito species could act as vectors. We conducted bloodmeal analyses of mosquitoes collected at Lomas Barbudal Biological Reserve, a dry tropical forest reserve in Costa Rica. Mosquitoes were collected using backpack aspirators and light, gravid, and resting traps, and then identified morphologically. Blood-fed mosquitoes underwent DNA extraction, PCR amplification, and sequencing of the vertebrate cytochrome b and cytochrome c oxidase 1 genes to identify vertebrate bloodmeal hosts. Several mosquitoes known to vector pathogens were found including Culex (Melanoconion) erraticus Dyar & Knab (Diptera: Culicidae), Cx. (Mel.) pedroi Sirivanakarn & Belkin, Aedes (Stegomyia) albopictus Skuse, Ae. (Ochlerotatus) scapularis Rondani, Ae. (Och.) serratus Theobald, and Ae. (Och.) taeniorhynchus Wiedemann. The most common bloodmeal hosts were basilisk lizards (Basiliscus vittatus) Wiegmann (Squamata: Corytophanidae) in Culex (Linnaeus) species and white-tailed deer (Odocoileus virginianus) Zimmermann (Artiodactyla: Cervidae) in Aedes (Meigen) species. These results show the diversity of mosquito species in a tropical dry deciduous forest and identify associations between mosquito vectors and potential pathogen reservoir hosts. Our study highlights the importance of understanding interactions between vector species and their hosts that could serve as predictors for the potential emergence or resurgence of mosquito-borne pathogens in Costa Rica. Universidad de Costa Rica/[803-B9-779]/UCR/Costa Rica Westminster College/[]//Estados Unidos The College of Wooster/[]//Estados Unidos UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias de la Salud::Centro de Investigación en Enfermedades Tropicales (CIET)

A new simple decision-tree (DT) algorithm was developed using the data from a neck-mounted accelerometer for real-time classification of feeding and ruminating behaviours of dairy cows. The performance of the DT was compared to that of a support vector machine (SVM) algorithm and a RumiWatch noseband sensor and the effect of decreasing the sampling rate of the accelerometer on the classification accuracy of the developed algorithms was investigated. Ten multiparous dairy cows were used in this study. Each cow was fitted with a RumiWatch halter and an accelerometer attached to the cow’s collar with both sensors programmed to log data at 10 Hz. Direct observations of the cows’ behaviours were used as reference (baseline data). Results indicate that the two sensors have similar classification performances for the considered behavioural categories (i.e., feeding, ruminating, other activity), with an overall accuracy of 93% for the accelerometer with SVM, 90% for the accelerometer with DT, and 91% for the Rumiwatch sensor. The difference between the predicted and the observed ruminating time (in min/h) was less than 1 min. h (1.5% of the observed time) for the SVM and less than 2 min. h (2.8%) for both DT and the RumiWatch. Similarly, the difference in feeding time was 1.3 min. h (2.1%) for the SVM compared to 2.5 min. h (4.3%) and 2.4 min. h (4.1%) for both RumiWatch and DT, respectively. These preliminary findings illustrate the potential of the collar-mounted accelerometer to classify feeding and ruminating behaviours with accuracy measures comparable to the Rumiwatch noseband sensor.

Place: Dordrecht Publisher: Springer WOS:000555361400001; International audience; Fisheries can profoundly affect bycatch species with 'slow' life history traits. Managing bait type offers one tool to control species selectivity. Different species and sizes of marine predators have different prey, and hence bait, preferences. This preference is a function of a bait's chemical, visual, acoustic and textural characteristics and size, and for seabirds the effect on hook sink rate is also important. We conducted a global meta-analysis of existing estimates of the relative risk of capture on different pelagic longline baits. We applied a Bayesian random effects meta-analytic regression modelling approach to estimate overall expected bait-specific catch rates. For blue shark and marine turtles, there were 34% (95% HDI: 4-59%) and 60% (95% HDI: 44-76%) significantly lower relative risks of capture on forage fish bait than squid bait, respectively. Overall estimates of bait-specific relative risk were not significantly different for seven other assessed taxa. The lack of a significant overall estimate of relative capture risk for pelagic shark species combined but significant effect for blue sharks suggests there is species-specific variability in bait-specific catch risk within this group. A qualitative literature review suggests that tunas and istiophorid billfishes may have higher catch rates on squid than fish bait, which conflicts with reducing marine turtle and blue shark catch rates. The findings from this synthesis of quantitative and qualitative evidence support identifying economically viable bycatch management measures with acceptable tradeoffs when multispecies conflicts are unavoidable, and highlight research priorities for global pelagic longline fisheries.

10 pages, 6 figures, 1 table, supplementary data https://doi.org/10.1016/j.marpolbul.2020.111399, We quantified the incidence of microplastics in the gut contents of the European sardine (Sardina pilchardus) and anchovy (Engraulis encrasicolus) in the Northwestern Mediterranean Sea and tested which variables influence this abundance, including the prevalence of parasites (i.e., trematoda larvae and nematodes). We detected a 58% occurrence of microplastics ingestion in sardines and a 60% in anchovies. With respect to sardines, the individuals with lower body conditions were found to have the highest microplastics ingestion probabilities, whereas in anchovies such probabilities were observed in individuals with higher gonadosomatic indices and smaller size. The areas with the highest microplastics ingestion probabilities were the Gulf of Alicante for sardines and the Gulf of Lion - Ebro Delta for anchovies. Both species showed a positive relationship between parasites and microplastics ingestion. These results highlight that both parasitism and ingestion of microplastics are concerns for the health of marine stocks and human consumers, This study was carried out within PELWEB (CTM2017-88939-R) and PELCAT (CAT 152CAT00013, TAIS ARP059/19/00005) projects. [...] MEDITS data collection has been co-funded by the EU through the European Maritime and Fisheries Fund (EMFF) within the National Program of collection, management and use of data in the fisheries sector and support for scientific advice regarding the Common Fisheries Policy, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

WOS:000502962100001; International audience; In marine ecosystems, carbon export is driven by particle flux which is modulated by aggregation, remineralization, and grazing processes. Zooplankton contribute to the sinking flux through the egestion of fast sinking fecal pellets but may also attenuate the flux by tearing apart phytoplankton aggregates into small pieces through swimming activity or direct ingestion. Freely suspended cells, artificial monospecific aggregates from two different diatom species (Chaetoceros neogracile and Skeletonema merinol) and natural aggregates of Melosira sp. were independently incubated with five different copepod species (Acadia clausi, Temora longicomis, Calanus helgolandicus, Euterpina acutifrons, and Calanus hyperboreus). During the grazing experiments initiated with free diatoms, E. acutifrons feeding activity evidenced by ingestion rates of 157 +/- 155 ng Chl a ind(-1) d(-1), induced a significant increase of S. marinoi aggregation. Transparent exopolymeric particles (TEP) production was only slightly boosted by the presence of grazers and turbulences created by swimming may be the main trigger of the aggregation processes. All copepods studied were able to graze on aggregates and quantitative estimates led to chlorophyll a ingestion rates (expressed in Chla a equivalent, i.e., the sum of chlorophyll a and pheopigments in their guts) ranging from 4 to 23 ng Chl a(eq) ind(-1) d(-1). The relation between equivalent spherical diameters (ESDs) and sinking velocities of the aggregates did not significantly change after grazing, suggesting that copepod grazing did not affect aggregate density as also shown by Si:C and C:N ratios. Three main trends in particle dynamics could be identified and further linked to the copepod feeding behavior and the size ratio between prey and predators: (1) Fragmentation of S. marinoi aggregates by the cruise feeder T. longicomis and of Melosira sp. aggregates by C. hyperboreus at prey to predator size ratios larger than 15; (2) no change of particle dynamics in the presence of the detritic cruise feeder E acutifrons; and finally (3) re-aggregation of C. neogracile and S. marinoi aggregates when the two filter feeders A. clausi and C. helgolandicus were grazing on aggregate at prey to predator size ratios lower than 10. Aggregation of freely suspended cells or small aggregates was facilitated by turbulence resulting from active swimming of small copepods. However, stronger turbulence created by larger cruise feeders copepods prevent aggregate formation and even made them vulnerable to breakage.

BackgroundEating a diet rich in fruit and vegetables is essential for healthy development, protects against chronicle diseases, and increases mental well-being. Numerous studies have consistently shown that children do not consume enough fruit and vegetables, especially among children from low socioeconomic status, while foods high in fat, sugar and salt are over-consumed. In order to improve children’s eating behavior, there is an urgent need to systematically test novel and effective methods to make fruit and vegetables more appealing and increase the intake among children. Therefore, the main aim of the proposed project is to test if food promotion techniques increase children’s fruit and vegetable intake, both on the short- and long-term.MethodsThree studies will be conducted. First, to develop the vlogs in co-creation, multiple focus groups will be held with (1) children (N = 25, between 8 and 13 years), (2) parents (N = 10), (3) vloggers (N = 5), and (4) fruit and vegetable producers and marketers (N = 5). Second, a multicenter randomized clinical trial will be conducted among 10 primary schools. A mixed repeated measure design with three different conditions will be used: (1) control, (2) a vlog unboxing fruit and vegetables (preparing and tasting), and (3) a vlog doing a challenge with the fruit and vegetables (e.g., contests, tricks, games). Children between 7 and 13 will participate in the experiments (N = 350). Third, after 6 and 12 months follow-up measurements will take place.DiscussionHFSS foods have higher intrinsically rewarding properties that make them more “wanted” and “liked” than fruit and vegetables, thereby inducing unhealthy eating behavior among children. Additionally, promotion for HFSS foods is omnipresent and increases the rewarding value of these foods. Moreover, some studies showed that the promotion of fruit and vegetables affects the intake, although a recent systematic review shows that evidence is inconclusive and a theoretical understanding for the underlying mechanism is missing. The current study aims to improve the existing knowledge by experimentally testing a newly developed theoretical model.Trial registrationNetherlands Trial registration:NL8077, received on 12 October 2019.

A prominent idea emerging from the study of sleep is that this key behavioural state is regulated in a complex fashion by ecologically and physiologically relevant environmental factors. This concept implies that sleep, as a behaviour, is plastic and can be regulated by external agents and changes in internal state. Drosophila melanogaster constitutes a resourceful model system to study behaviour. In the year 2000, the utility of the fly to study sleep was realised, and has since extensively contributed to this exciting field. At the centre of this review, we will discuss studies showing that temperature, food availability/quality, and interactions with conspecifics can regulate sleep. Indeed the relationship can be reciprocal and sleep perturbation can also affect feeding and social interaction. In particular, different environmental temperatures as well as gradual changes in temperature regulate when, and how much flies sleep. Moreover, the satiation/starvation status of an individual dictates the balance between sleep and foraging. Nutritional composition of diet also has a direct impact on sleep amount and its fragmentation. Likewise, aggression between males, courtship, sexual arousal, mating, and interactions within large groups of animals has an acute and long-lasting effect on sleep amount and quality. Importantly, the genes and neuronal circuits that relay information about the external environment and internal state to sleep centres are starting to be elucidated in the fly and are the focus of this review. In conclusion, sleep, as with most behaviours, needs the full commitment of the individual, preventing participation in other vital activities. A vast array of behaviours that are modulated by external and internal factors compete with the need to sleep and thus have a significant role in regulating it.

Feeding is a complex behaviour comprised of satiety control, foraging, ingestion and subsequent digestion. Cichlids from the East African Great Lakes are renowned for their diverse trophic specializations, largely predicated on highly variable jaw morphologies. Thus, most research has focused on dissecting the genetic, morphological and regulatory basis of jaw and teeth development in these species. Here for the first time we explore another aspect of feeding, the regulation of appetite related genes that are expressed in the brain and control satiety in cichlid fishes. Using qPCR analysis, we first validate stably expressed reference genes in the brain of six haplochromine cichlid species at the end of larval development prior to foraging. We next evaluate the expression of 16 appetite related genes in herbivorous and carnivorous species from the parallel radiations of Lake Tanganyika, Malawi and Victoria. Interestingly, we find increased expression of two anorexigenic genes, cart and npy2r, in the brain of carnivorous species in all the lakes. This supports the notion that herbivory compared to carnivory requires stronger appetite stimulation in order to feed larger quantity of food and to compensate for the relatively poorer nutritional quality of a plant- and algae-based diet. Our study contributes to the limited body of knowledge on the neurological circuitry that controls feeding transitions and adaptations and in cichlids and other teleosts.

Summary Sensory cues in the natural environment predict reward or punishment, important for survival. For example, the ability to detect attractive tastes indicating palatable food is essential for foraging while the recognition of inedible substrates prevents harm. While some of these sensory responses are innate, they can undergo fundamental changes due to prior experience associated with the stimulus. However, the mechanisms underlying such behavioral switching of an innate sensory response at the neuron and network levels require further investigation. We used the model learning system of Lymnaea stagnalis1, 2, 3 to address the question of how an anticipated aversive outcome reverses the behavioral response to a previously effective feeding stimulus, sucrose. Key to the switching mechanism is an extrinsic inhibitory interneuron of the feeding network, PlB (pleural buccal4,5), which is inhibited by sucrose to allow a feeding response. After multi-trial aversive associative conditioning, pairing sucrose with strong tactile stimuli to the head, PlB’s firing rate increases in response to sucrose application to the lips and the feeding response is suppressed; this learned response is reversed by the photoinactivation of a single PlB. A learning-induced persistent change in the cellular properties of PlB that results in an increase rather than a decrease in its firing rate in response to sucrose provides a neurophysiological mechanism for this behavioral switch. A key interneuron, PeD12 (Pedal-Dorsal 12), of the defensive withdrawal network5,6 does not mediate the conditioned suppression of feeding, but its facilitated output contributes to the sensitization of the withdrawal response., Graphical abstract, Highlights • Anticipation of an aversive outcome reverses the behavioral response to food. • The switching mechanism relies on an interneuron extrinsic to the feeding network. • Aversive learning causes persistent physiological change in this interneuron., Pirger et al. demonstrate that persistent modulation of an inhibitory interneuron extrinsic to the feeding system can switch the behavioral response so that a previously salient food stimulus elicits an aversive response. Anticipation of punishment associated with food induces excitation of an interneuron that inhibits the feeding network.

Objective Imprinted genes are crucial for the growth and development of fetal and juvenile mammals. Altered imprinted gene dosage causes a variety of human disorders, with growth and development during these crucial early stages strongly linked with future metabolic health in adulthood. Neuronatin (Nnat) is a paternally expressed imprinted gene found in neuroendocrine systems and white adipose tissue and is regulated by the diet and leptin. Neuronatin expression is downregulated in obese children and has been associated with stochastic obesity in C57BL/6 mice. However, our recent studies of Nnat null mice on this genetic background failed to display any body weight or feeding phenotypes but revealed a defect in glucose-stimulated insulin secretion due to the ability of neuronatin to potentiate signal peptidase cleavage of preproinsulin. Nnat deficiency in beta cells therefore caused a lack of appropriate storage and secretion of mature insulin. Methods To further explore the potential role of Nnat in the regulation of body weight and adiposity, we studied classical imprinting-related phenotypes such as placental, fetal, and postnatal growth trajectory patterns that may impact upon subsequent adult metabolic phenotypes. Results Here we find that, in contrast to the lack of any body weight or feeding phenotypes on the C57BL/6J background, deletion of Nnat in mice on 129S2/Sv background causes a postnatal growth restriction with reduced adipose tissue accumulation, followed by catch up growth after weaning. This was in the absence of any effect on fetal growth or placental development. In adult 129S2/Sv mice, Nnat deletion was associated with hyperphagia, reduced energy expenditure, and partial leptin resistance. Lack of neuronatin also potentiated obesity caused by either aging or high fat diet feeding. Conclusions The imprinted gene Nnat plays a key role in postnatal growth, adult energy homeostasis, and the pathogenesis of obesity via catch up growth effects, but this role is dependent upon genetic background., Highlights • Deletion of the imprinted gene neuronatin in mice alters postnatal growth. • This postnatal growth defect and subsequent catch up growth is background-specific. • Leads to reduced energy expenditure, hyperphagia and leptin resistance in adulthood. • Nnat null mice are more susceptible to obesity via aging or high fat diet feeding. • Defects in normal insulin and growth hormone secretion may underpin these findings.

Group housing of gestating sows benefits their welfare by allowing them freedom of movement and the opportunity for social interaction. However, social life could also bring disadvantages for individuals who receive direct aggression or are displaced from the feeder. The aim of this study was to investigate associations between social behaviour, body condition and live weight. Gestating sows (n=298) were investigated on a commercial farm. Sows were housed in mixed parity groups where two single space, ad libitum trough feeders served 12 animals. Sows were weighed, body condition scored and had their back fat layer measured at mixing, 4 weeks after insemination and again before farrowing. Social status was estimated based on the numbers of won and lost agonistic interactions at mixing and at the end of gestation. In addition, tear staining was scored before the farrowing and reproductive performance data were collected. With the aid of video recordings, 100 to 150 interactions per group were observed. Winning percentage at mixing and at the end of gestation were associated (Plt;0.05) and appeared relatively stable within individuals. Tear staining scores and litter sizes were not associated with winning percentage at the end of gestation. However, live weight, relative weight, body condition and back fat thickness were associated with winning percentage (Plt;0.05), giving heavier animals an advantage. Low winning percentage related to lower live weight gain, probably due to poorer success in competition for feed. Live weight within a mixed parity group could be used as a proxy measure for social status. Sows with low body condition score and submissive sows might need special attention with regard to group dynamics and housing to alleviate the effects of competition in group housing.

On-farm death (OFD) of a dairy cow is always a financial loss for a farmer, and potentially a welfare issue that has to be addressed within the dairy industry. The aim of this study was to explore the associations between OFD of dairy cows, housing, and herd management in freestall barns. To achieve the goal, we followed 10,837 cows calving in 2011 in 82 herds. Data were gathered with observations and a structured interview during farm visits and from a national dairy herd improvement database. The hazard of OFD was modeled with a shared frailty survival model, with SAS 9.3 PHREG procedure (SAS Institute Inc., Cary, NC). The study population was 58% Ayrshire and 42% Holstein cows. The median herd size and mean milk yield in the study herds were 116 cows and 9,151 kg of milk per cow per year. The overall probability of OFD was 6.0%; 1.8% of the cows died unassisted and 4.2% were euthanized. Variation in OFD percentage between individual herds was large, from 0 to 16%, accounting for 0 to 58% of all removals in the herds. Keeping close-up dry cows in an own group was associated with higher hazard of OFD [hazard ratio (HR) = 1.37] compared with keeping them in the same pen with far-off dry cows. Higher hazard on OFD was observed when barns had only one kind of calving pens; single (HR = 2.09) or group pens (HR = 1.72), compared with having both of those types. The hazard of OFD was lower if the whole herd was housed in barns or pens that had only 1 type of feed barrier at the feed bunk, namely post-and-rail (HR = 0.51) or a type with barriers between the cow's heads (HR = 0.49), compared with having 2 types. Lower OFD hazard was observed with wider than 340 cm of walking alley next to the feeding table (HR = 0.75), and with housing a whole herd in pens with only 1 type of walking alley surface, specifically slatted (HR = 0.53) or solid (HR = 0.48), compared with having both types. The hazard of OFD was higher with stalls wider than 120 cm (HR = 1.38) compared with narrower stalls. The hazard of OFD was also associated with breed, parity, and calving season. This study identified many factors that contribute to the incidence of OFD of dairy cows. The solutions for reducing on-farm mortality include housing, management, and breeding choices that are most probably herd specific.

Salt intake is an essential dietary requirement, but excessive consumption is implicated in hypertension and associated conditions. Little is known about the neural circuit mechanisms that control motivation to consume salt, although the midbrain dopamine system, which plays a key role in other reward-related behaviors, has been implicated. We, therefore, examined the effects on salt consumption of either optogenetic excitation or chemogenetic inhibition of ventral tegmental area (VTA) dopamine neurons in male mice. Strikingly, optogenetic excitation of dopamine neurons decreased salt intake in a rapid and reversible manner, despite a strong salt appetite. Importantly, optogenetic excitation was not aversive, did not induce hyperactivity, and did not alter salt concentration preferences in a need-free state. In addition, we found that chemogenetic inhibition of dopamine neurons had no effect on salt intake. Lastly, optogenetic excitation of dopamine neurons reduced consumption of sucrose following an overnight fast, suggesting a more general role of VTA dopamine neuron excitation in organizing motivated behaviors.

Trophic interactions at the basis of food webs, for instance between meiofauna, primary producers and bacteria, are key drivers of benthic energy fluxes. Yet both qualitative and quantitative information about meiofaunal resource utilization under in situ conditions is scant. By means of natural stable isotope ratios of carbon and nitrogen and of fatty acid (FA) profiles, we examined the variability of in situ resource utilization of a range of harpacticoid copepod species from 5 stations in an estuarine intertidal area. These stations, located in different habitats, differed in sediment granulometry, resource availability, presence/absence of vegetation and other environmental variables, as well as in copepod species composition. Our goal was to describe inter-specific differences among harpacticoid species, as well as spatio-temporal variability within species. Despite differences in resource availability between habitats, d13C data clearly point at microphytobenthos (MPB) as the major carbon source to the harpacticoid assemblages at all 5 stations. Small differences in carbon isotopic ratios between co-occurring species indicate some degree of resource differentiation, whereas both the d15N and FA composition suggest that several harpacticoid species obtain MPB carbon indirectly, perhaps through feeding on bacteria or ciliates. For a limited number of species, such as Paraleptastacus spinicauda, clear dietary contributions of suspended particulate matter and bacteria were found, and MPB appeared to have only a small or no contribution. Even in vegetated salt-marsh stations, Spartina anglica detritus did not appear to contribute to copepod diets. The d13C of Cletodidae were highly depleted, reflecting a contribution of methane-derived carbon.

For hundreds of millions of years, large vertebrates (megafauna) have inhabited most of the ecosystems on our planet. During the late Quaternary, notably during the Late Pleistocene and the early Holocene, Earth experienced a rapid extinction of large, terrestrial vertebrates. While much attention has been paid to understanding the causes of this massive megafauna extinction, less attention has been given to understanding the impacts of loss of megafauna on other organisms with whom they interacted. In this review, we discuss how the loss of megafauna disrupted and reshaped ecological interactions, and explore the ecological consequences of the ongoing decline of large vertebrates. Numerous late Quaternary extinct species of predators, parasites, commensals and mutualistic partners were associated with megafauna and were probably lost due to their strict dependence upon them (co-extinctions). Moreover, many extant species have megafauna-adapted traits that provided evolutionary benefits under past megafauna-rich conditions, but are now of no or limited use (anachronisms). Morphological evolution and behavioural changes allowed some of these species partially to overcome the absence of megafauna. Although the extinction of megafauna led to a number of co-extinction events, several species that likely co-evolved with megafauna established new interactions with humans and their domestic animals. Species that were highly specialized in interactions with megafauna, such as large predators, specialized parasites, and large commensalists (e.g. scavengers, dung beetles), and could not adapt to new hosts or prey were more likely to die out. Partners that were less megafauna dependent persisted because of behavioural plasticity or by shifting their dependency to humans via domestication, facilitation or pathogen spill-over, or through interactions with domestic megafauna. We argue that the ongoing extinction of the extant megafauna in the Anthropocene will catalyse another wave of co-extinctions due to the enormous diversity of key ecological interactions and functional roles provided by the megafauna., M.G. and J‐C.S. thank the Aarhus University Research Foundation for a guest researcher grant to sponsor M.G. at Aarhus University. J‐C.S. considers this work a contribution to his Carlsberg Foundation Semper Ardens project MegaPast2Future (CF16‐0005) and to his VILLUM Investigator project ‘Biodiversity Dynamics in a Changing World’ funded by VILLUM FONDEN. M.M. and P.J. were supported by the Severo Ochoa Program for Centres of Excellence in R+D+I (SEV‐2012‐0262) and M.M. by a Ramón y Cajal (RYC‐2015‐19231) grant. M.G. and P.R.G. have a fellowship from Conselho Nacional de Desenvolvimento Científico (CNPq, 300241/2010‐0). M.G. and M.M.P. thank São Paulo Research Foundation (FAPESP, 2014/01986‐0, 2013/22016‐6) for financial support.

Summary The aim of this study was to assess the effects of particle size (PS) of alfalfa hay on growth characteristics and rumen development in dairy calves at two levels of alfalfa supplementation. Fifty newborn dairy calves (42.7 ± 2.2 kg BW) were used in a 2 × 2 factorial arrangement with the factors supplementation level (low, 8%; or high, 16% on DM basis) and PS (medium, 2.92 mm; or long, 5.04 mm as geometrical means) of alfalfa hay. In addition, a control group without alfalfa hay was used. Hence, treatments were: control (C); low level with medium PS (LM); low level with long PS (LL); high level with medium PS (HM) or high level with long PS (HL). Growth performance of alfalfa-fed calves did not differ from control calves, but alfalfa supplementation decreased corneum thickness of the rumen wall. In alfalfa-fed calves, post-weaning starter intake was greater for LL calves than for LM calves. During the entire rearing period, starter intake was 26–32% higher for LL and HM calves than for LM calves. Pre-weaning average daily gain was higher for LL and HM calves than for HL calves, but this effect was not persistent over the entire rearing period. Final body weight decreased from 86 to 79 kg when the level of long PS alfalfa hay increased from 8 to 16%, but increased from 78 to 87 kg when the level of medium PS alfalfa increased from 8 to 16%. Regardless of PS and level, morphometric characteristics of rumen wall were generally similar among alfalfa feeding groups, but corneum thickness decreased from 8.7 to 6.1 μm with greater PS at the low level. These results indicate that adequate, but not excessive, physical stimulation is required for appropriate rumen development and growth performance of dairy calves.

International audience; We looked at how three ecological tracers may influence the characterization and interpretation of trophic structures in a tropical marine system, with a view to informing tracer(s) selection in future trophic ecology studies. We compared the trophic structures described by stable isotope compositions (carbon and nitrogen), the total mercury concentration (THg) and levels of essential fatty acids (EFA) at both the individual and species level. Analyses were undertaken on muscle tissue samples from fish and crustacean species caught in the waters surrounding the Seychelles. The carbon isotope composition (δ13C) correlated to the proportion of arachidonic acid (ARA), whereas the nitrogen isotope composition (δ15N) correlated to the proportion of docosahexaenoic acid (DHA) and THg. At the individual level, trophic position obtained with these three last tracers are similar. In contrast, the eicosapentaenoic acid (EPA) was not clearly correlated to any of the tracers. At the species level, the use of EFA (ARA and DHA), as compared to stable isotopes, resulted in slight structural modifications, mainly in the middle trophic levels. For example, the EFA overestimated the trophic positions of Thunnus alalunga and Etelis coruscans but underestimated the trophic positions of other snappers and groupers. While ARA mainly originates from coastal/benthic areas, DHA is conserved throughout the food web and may be used as a proxy indicator of trophic position. However, metabolic disparities can affect ecological tracers and in turn, distort the trophic structures derived from their results. This is especially true for species with close trophic ecologies. Despite these caveats, we think that analysing at the individual level the wealth of ARA, DHA and THg data that has already been obtained through earlier nutrition or food security studies would enhance our understanding of trophic structures.

International audience; Recently, Apolygus lucorum (Hemiptera: Miridae) has become an important insect pest of Bt cotton and fruit trees in China. At present, the application of chemical insecticides is the main control option for this pest. We investigated the lethal effect of seven neonicotinoid insecticides on A. lucorum adults, including six commercialized neonicotinoids and a novel one, cycloxaprid, which is developed in China. In addition, we assessed the sublethal physiological (longevity, fecundity) and behavioral (preoviposition and oviposition periods) effects of LD10 (low lethal dose) and LD40 (moderate lethal dose) of cycloxaprid on the mirid bug. Lethal effect of the insecticides was determined using a topical exposure method; contact toxicity against the adults was ranked as follows: cycloxaprid, nitenpyram > clothianidin > acetamiprid, imidacloprid > thiamethoxam > dinotefuran. Among these insecticides, the toxicity of cycloxaprid against the adults was the highest; its LD50 value was 2.54 ng a.i .(active ingredient)/adult. Both LD10 (0.74 ng a. i./adult) and LD40 (1.98 ng a. i./ adult) of cycloxaprid induced sublethal effects in the adults; we observed a reduced longevity in males and the LD40 also shortened the longevity of females. In addition, the LD40 prolonged the pre-oviposition period and shortened the oviposition period of females, and it decreased their fecundity. The hatching rate of eggs laid by the females exposed to LD10 and LD40 greatly decreased (two-fold lower when exposed to LD40). Our results demonstrate that cycloxaprid is among the best candidate insecticides for controlling A. lucorum, and it showed significant lethal and sublethal effects on this mirid bug.

Dinoflagellates constitute a large proportion of the planktonic biomass from marine to freshwater environments. Some species produce a preservable organic-walled resting cyst (dinocyst) during the sexual phase of their life cycle that is an important link between the organisms, the environment in which their parent motile theca grew, and the sedimentary record. Despite their abundance and widespread usage as proxy indicators for environmental conditions, there is a lack of knowledge regarding the dinocyst wall chemical composition. It is likely that numerous factors, including phylogeny and life strategy, determine the cyst wall chemistry. However, the extent to which this composition varies based on inherent (phylogenetic) or variable (ecological) factors has not been studied. To address this, we used micro-Fourier transform infrared spectroscopy to analyze nine cyst species produced by either phototrophic or heterotrophic dinoflagellates from the extant orders Gonyaulacales, Gymnodiniales, and Peridiniales. Based on the presence of characteristic functional groups, two significantly different cyst wall compositions are observed that correspond to the dinoflagellate's nutritional strategy. The dinocyst wall compositions analyzed appeared carbohydrate-based, but the cyst wall produced by phototrophic dinoflagellates suggested a cellulose-like glucan, while heterotrophic forms produced a nitrogen-rich glycan. This constitutes the first empirical evidence nutritional strategy is related to different dinocyst wall chemistries. Our results indicated phylogeny was less important for predicting composition than the nutritional strategy of the dinoflagellate, suggesting potential for cyst wall chemistry to infer past nutritional strategies of extinct taxa preserved in the sedimentary record.

Calves raised for milk or meat are fed diets that differ from feral-herd calf diets and are based on the nutritional requirements of the ‘average calf’. These diets may not meet the dietary preferences of each individual calf. This study explored diet preferences in calves with free dietary choice, and the effect of these preferences on behaviour. Group-housed Holstein-Friesian bull calves (N = 23) were given unlimited access to five diet components (i.e. milk replacer [MR], concentrate, maize silage, long hay and long barley straw). At 3 and 6 months of age, calves were moved for 7 days to an automated test pen in groups of four, where intake, time spent eating, and visit frequency to each diet component was recorded to assess preferences. Behaviour was recorded on 2 of the 7 days in the test pen, from 07:30 to 18:00 h using instantaneous scan sampling for periods of 30 min every 2.5 h at a 2 min interval. Solid feed intake at 6 months averaged 3205.5 ± 174.6 g DM d-1. At 3 months, calves selected the following proportion (average of individual proportions) of MR, concentrate and roughage in relation to total g DM intake: 51.6 ± 5.0%, 25.0 ± 4.7% and 23.4 ± 2.8%. At 6 months, the calves conserved the roughage proportion (23.3 ± 1.6%), but increased concentrate intake (47.1 ± 2.1%) at the expense of MR (29.6 ± 1.9%). Order of preference for the five diet components varied according to whether intake, time spent eating each component, or visit frequency was considered. On the whole, MR was preferred followed by concentrate and hay at both ages. Offering a dietary choice led to large individual variation in intake and to 47–80% calves having the same ranking as the average ranking for diet components. This suggests diets based on the ‘average calf’ may meet only few calves’ dietary preferences. Different variables showed different preference rankings and studies in the future should consider the relative importance of these variables in assessing animal preferences. Keywords: Behaviour, Dietary preference, Holstein-Friesian calves, Milk replacer, Solid feed, Welfare

Parasitic infections are often followed by changes in host behaviour. Numerous and exquisite examples of such behavioural alterations are known, covering a broad spectrum of parasites and hosts. Most descriptions of such parasite-induced changes in host behaviour are observational reports, while experimentally confirmed examples of parasite genes inducing these changes are limited. In this study, we review changes in invertebrate host behaviour observed upon infection by parasites and discuss such changes in an evolutionary context. We then explore possible mechanisms involved in parasite-induced changes in host behaviour. Genes and pathways known to play a role in invertebrate behaviour are reviewed, and we hypothesize how parasites (may) affect these pathways. This review provides the state of the art in this exciting, interdisciplinary field by exploring possible pathways triggered in hosts, suggesting methodologies to unravel the molecular mechanisms that lead to changes in host behaviour.

Solanum galapagense is closely related to the cultivated tomato and can show a very good resistance towards whitefly. A segregating population resulting from a cross between the cultivated tomato and a whitefly resistant S. galapagense was created and used for mapping whitefly resistance and related traits, which made it possible to study the genetic basis of the resistance. Quantitative trait loci (QTL) for adult survival co-localized with type IV trichome characteristics (presence, density, gland longevity and gland size). A major QTL (Wf-1) was found for adult survival and trichome characters on Chromosome 2. This QTL explained 54.1 % of the variation in adult survival and 81.5 % of the occurrence of type IV trichomes. A minor QTL (Wf-2) for adult survival and trichome characters was identified on Chromosome 9. The major QTL was confirmed in F3 populations. Comprehensive metabolomics, based on GCMS profiling, revealed that 16 metabolites segregating in the F2 mapping population were associated with Wf-1 and/or Wf-2. Analysis of the 10 most resistant and susceptible F2 genotypes by LCMS showed that several acyl sugars were present in significantly higher concentration in the whitefly resistant genotypes, suggesting a role for these components in the resistance as well. Our results show that whitefly resistance in S. galapagense seems to inherit relatively simple compared to whitefly resistance from other sources and this offers great prospects for resistance breeding as well as elucidating the underlying molecular mechanism(s) of the resistance.

The global obesity epidemic has resulted in significant morbidity and mortality. However, the medical treatment of obesity is limited. Gastric bypass is an effective surgical treatment but carries signifi cant perioperative risks. The gut hormones, peptide tyrosine tyrosine (PYY) and glucagon-like peptide 1 (GLP-1), are elevated following gastric bypass and have been shown to reduce food intake. They may provide new therapeutic targets. This review article provides an overview of the central control of food intake and the role of PYY and GLP-1 in appetite control. Key translational animal and human studies are reviewed. (Gut Liver 2012;6:10-20)

The solenopsis mealybug, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae), is a polyphagous insect known to cause severe damage to cotton (especially transgenic varieties) in South Asia, and currently poses a serious threat in Asia and potentially elsewhere. Stylet penetration behavior of P. solenopsis on cotton was monitored using the electrical penetration graph (EPG) technique (DC system) and the EPG characteristics were compared with those previously published from Phenacoccus manihoti Matile-Ferrero and Planococcus citri (Risso). We identified and further characterized typical waveforms of A, B, C, and pd (together pathway), E1 and E2 (phloem), F (derailed stylet mechanics), and G (xylem). Five novel EPG aspects were distinguished in the EPG waveforms from P. solenopsis: (1) obvious B waveforms occurred following waveform A, (2) during waveform C, some aphid-like E1e waveforms were observed, (3) prolonged potential drops (pd) up to >1 h occurred with two continuously alternating sub-phases pd1 and pd2, (4) the pd1 waveform always occurred as the first waveform related to phloem sieve elements, preceding the other phloem waveforms (E), the labeling of which we changed to achieve a better comparison to the aphid E waveforms, and (5) waveform F, related to derailed stylet mechanics occurred but was not reported from other mealybugs so far. This is mainly a waveform morphology study to extend existing knowledge on mealybug EPGs to investigate mealybug-host plant interactions. Further experimental verification of waveform correlations with plant tissue positions of stylet tips and insect activities is still needed.

We review the conservation issues facing migratory shorebird populations that breed in temperate regions and use wetlands in the non-breeding season. Shorebirds are excellent model organisms for understanding ecological, behavioural and evolutionary processes and are often used as indicators of wetland health. A global team of experienced shorebird researchers identified 45 issues facing these shorebird populations, and divided them into three categories (natural, current anthropogenic and future issues). The natural issues included megatsunamis, volcanoes and regional climate changes, while current anthropogenic threats encompassed agricultural intensification, conversion of tidal flats and coastal wetlands by human infrastructure developments and eutrophication of coastal systems. Possible future threats to shorebirds include microplastics, new means of recreation and infectious diseases. We suggest that this review process be broadened to other taxa to aid the identification and ranking of current and future conservation actions.

Samples collected at two different depths (ca. 3200 and ca. 4200 m) in the Setúbal and Cascais canyons off the Portuguese coast, during the HERMES RRS Charles Darwin cruise CD179, were analysed for (1) sediment biogeochemistry (TOC, TN) and (2 composition, and structural and trophic diversity of nematode communities. Multivariate PERMANOVA analysis on the nematode community data revealed differences between sediment layers that were greater than differences between canyons, water depths, and stations. This suggests that biogeochemical gradients along the vertical sediment profile are crucial in determining nematode community structure. The interaction between canyon conditions and the nematode community is illustrated by biogeochemical patterns in the sediment and the prevalence of nematode genera that are able to persist in disturbed sediments. Trophic analysis of the nematode community indicated that non-selective deposit feeders are dominant, presumably because of their non-selective feeding behaviour compared to other feeding types, which gives them a competitive advantage in exploiting lower-quality food resources. This study presents a preliminary conceptual scheme for interactions between canyon conditions and the resident fauna.

Volatile fatty acids (VFA), produced in the rumen by microbial fermentation, are the main energy source for ruminants. The VFA profile, particularly the nonglucogenic (acetate, Ac; butyrate, Bu) to glucogenic (propionate, Pr) VFA ratio (NGR), is associated with effects on methane production, milk composition, and energy balance. The aim of this study was to evaluate extant rumen VFA stoichiometry models for their ability to predict in vivo VFA molar proportions. The models were evaluated using an independent data set consisting of 101 treatments from 24 peer-reviewed publications with lactating Holstein cows. All publications contained a full diet description, rumen pH, and rumen VFA molar proportions. Stoichiometric models were evaluated based on root mean squared prediction error (RMSPE) and concordance correlation coefficient (CCC) analysis. Of all models evaluated, the 1998 Friggens model had the lowest RMSPE for Ac and Bu (7.2 and 20.2% of observed mean, respectively). The 2006 Bannink model had the lowest RMSPE and highest CCC for Pr (14.4% and 0.70, respectively). The 2008 Bannink model had comparable predictive performance for Pr to that of the 2006 Bannink model but a larger error due to overall bias (26.2% of MSPE). The 1982 Murphy model provided the poorest prediction of Bu, with the highest RMSPE and lowest CCC (24.6% and 0.15, respectively). The 1988 Argyle and Baldwin model had the highest CCC for Ac with an intermediate RMSPE (0.47 and 8.0%, respectively). The 2006 Sveinbjörnsson model had the highest RMSPE (13.9 and 34.0%, respectively) and lowest CCC (0.31 and 0.40, respectively) for Ac and Pr. The NGR predictions had the lowest RMSPE and highest CCC in the 2 models of Bannink, whereas the lowest predictive performance was in the 2006 Sveinbjörnsson model. It appears that the type of VFA produced is not a simple linear relationship between substrate inputs and pH as currently represented. The analysis demonstrates that most rumen VFA stoichiometric approaches explain a large part of the variation in VFA molar proportions among diets, in particular for Ac, whereas predictive power for Pr and Bu differ largely among approaches. The move toward feed evaluation systems based on animal response might necessitate an improved representation of rumen fermentation, focused on improving our understanding of VFA proportions in diets that vary from the mean.

Amphibians generally require moving preys to elicit feeding behaviour. In addition, since feeding capacity is linked to learning and memory capacities in many animals, the idea has long prevailed that amphibians were somewhat impoverished in this regard. As a result, there is currently no frog farming in Europe. However, in the 1990s, we succeeded in getting Rana ridibunda to accept pellets. R. ridibunda is a European frog belonging to the esculenta complex, which is composed of two species: Rana lessonae (LL) and R. ridibunda (RR) and their natural hybridogenetic hybrid Rana esculenta (RL). This latter taxon can be either diploid or triploid (RLL or RRL). For rearing purposes, we need to compare the learning and memory capacities of the components of this complex in relation to artificial feeding. While froglets of all taxa from the esculenta complex seem able to eat pellets, various results are obtained according to the genotype and origin of the parents. Generally, froglets from RR pairs have high survival rates (0.59-0.79), but the presence of only one L genome in the hybrid male is sufficient to reduce the survival rate (0.08-0.54). This reduction in survival is also observed in all pairs made up of an LL female and a male from various genotypes. The RL hybrid females produce smaller outputs (0-0.49) irrespective of the male genotype. The froglets from wild RR females paired with the common triploid RLL show a good survival rate (0.54), but this drops sharply with the rare RRL (0.08). The RR females from intensive rearing yield good results with RR males (0.66-0.78), somewhat lower with triploids (0.26 with RLL or RRL). LL females from one site paired with local diploid males give rise to progenies with a good survival rate (0.45-0.54), but this becomes worse (0.17) with RLL triploid. On the other hand, LL females from another site yield lower rates (0.07-0.11), which even fall to zero for corresponding RL females, whatever the genotype of the males. While pellet odour can be a feeding stimulus learnt during the tadpole stage, it is more associated with a particular stimulation of froglets during the beginning of their sub-aerial life, which varies according to the population history. Social facilitation seems to act as a feeding stimulus by direct and indirect effects (free-moving among floating pellets). Frogs, as primitive animals, are thus able to carry out cognitive tasks under the extreme conditions of artificial rearing. (C) 2010 Elsevier B.V. All rights reserved.

The hypothalamic control of energy balance is regulated by a complex network of neuropeptide-releasing neurons. Although the effect of these neuropeptides on individual aspects of energy homoeostasis has been studied, the coordinated response of these effects has not been comprehensively investigated. We have simultaneously monitored a number of metabolic parameters following intracerebroventricular (ICV) administration of 1 and 3 nmol of neuropeptides with established roles in the regulation of feeding, activity and metabolism. Ad libitum- fed rats received the orexigenic neuropeptides neuropeptide Y (NPY), agouti-related protein (AgRP), melanin-concentrating hormone (MCH) or orexin-A. Overnight-food-deprived rats received an ICV injection of the anorectic peptides alpha-melanocyte-stimulating hormone (MSH), corticotrophin-releasing factor (CRF) or neuromedin U (NMU).Our results reveal the temporal sequence of the effects of these neuropeptides on both energy intake and expenditure, highlighting key differences in their function as mediators of energy balance. NPY and AgRP increased feeding and decreased oxygen consumption, with the effects of AgRP being more prolonged. In contrast, orexin-A increased both feeding and oxygen consumption, consistent with an observed increase in activity. The potent anorexigenic effects of CRF were accompanied by a prolonged increase in activity, whereas NMU injection resulted in significant but short-lasting inhibition of food intake, ambulatory activity and oxygen consumption. alpha-MSH injection resulted in significant increases in both ambulatory activity and oxygen consumption, and reduced food intake following administration of 3 nmol of the peptide.We have for the first time, simultaneously measured several metabolic parameters following hypothalamic administration of a number of neuropeptides within the same experimental system. This work has shown the interrelated effects of these neuropeotides on activity, energy expenditure and food intake, thus facilitating comparison between the different hypothalamic systems.

Outcome in anorexia nervosa remains poor and a new way of looking at this condition is therefore needed. To this aim, we review the effects of food restriction and starvation in humans. It is suggested that body weight remains stable and relatively low when the access to food requires a considerable amount of physical activity. In this condition, the human homeostatic phenotype, body fat content is also low and as a consequence, the synthesis and release of brain neurotransmitters are modified. As an example, the role of neuropeptide Y is analyzed in rat models of this state. It is suggested that the normal behavioral role of neuropeptide Y is to facilitate the search for food and switch attention from sexual stimuli to food. Descriptive neuroendocrine studies on patients with anorexia nervosa have not contributed to the management of the patients and the few studies in which hormones have been administered have, at best, reversed an endocrine consequence secondary to starvation. In a modified framework for understanding the etiology and treatment of anorexia nervosa it is suggested that the condition emerges because neural mechanisms of reward and attention are engaged. The neural neuropeptide Y receptor system may be involved in the maintenance of the behavior of eating disorder patients because the localization of these receptors overlaps with the neural systems engaged in cue-conditioned eating in limbic and cortical areas. The eating behavior of patients with anorexia nervosa, and other eating disorders as well, is viewed as a cause of the psychological changes of the patients. Patients are trained to re-learn normal eating habits using external support and as they do, their symptoms, including the psychological symptoms, dissolve. (C) 2008 Elsevier Inc. All rights reserved.

Outcome in anorexia nervosa remains poor and a new way of looking at this condition is therefore needed. To this aim, we review the effects of food restriction and starvation in humans. It is suggested that body weight remains stable and relatively low when the access to food requires a considerable amount of physical activity. In this condition, the human homeostatic phenotype, body fat content is also low and as a consequence, the synthesis and release of brain neurotransmitters are modified. As an example, the role of neuropeptide Y is analyzed in rat models of this state. It is suggested that the normal behavioral role of neuropeptide Y is to facilitate the search for food and switch attention from sexual stimuli to food. Descriptive neuroendocrine studies on patients with anorexia nervosa have not contributed to the management of the patients and the few studies in which hormones have been administered have, at best, reversed an endocrine consequence secondary to starvation. In a modified framework for understanding the etiology and treatment of anorexia nervosa it is suggested that the condition emerges because neural mechanisms of reward and attention are engaged. The neural neuropeptide Y receptor system may be involved in the maintenance of the behavior of eating disorder patients because the localization of these receptors overlaps with the neural systems engaged in cue-conditioned eating in limbic and cortical areas. The eating behavior of patients with anorexia nervosa, and other eating disorders as well, is viewed as a cause of the psychological changes of the patients. Patients are trained to re-learn normal eating habits using external support and as they do, their symptoms, including the psychological symptoms, dissolve. (C) 2008 Elsevier Inc. All rights reserved.

Serotonin (5-HT)(1A) and 5-HT(1B) receptors have been implicated in the incidence and treatment of depression in part through the examination of animals lacking these receptors. Although these receptors have been repeatedly implicated in ingestive behavior there is little information about how 5-HT(1A) and 5-HT(1B) receptor mutant mice react to solutions of varying palatability. In the present experiment male and female 5-HT(1A) and 5-HT(1B) mutant and wild-type mice were presented with increasing concentrations of sucrose using a two-bottle choice procedure. In addition fasting blood glucose levels were assessed. Both male and female 5-HT(1B) mutant mice drank more sucrose than WT mice but also consumed more water. Female, but not male, 5-HT(1A) mutant mice similarly showed increased sucrose consumption, but did not demonstrate increased consumption of water. In addition, the pattern of increased sucrose consumption over genotype and sex was related to fasting blood glucose concentrations such that levels in male 5-HT(1B) mutant mice were reduced relative to wild-type and 5-HT(1A) mutant males, but similar to those of females. The findings in 5-HT(1B) mutant mice emphasize the role of the 5-HT(1B) receptor in regulating ingestive behavior, whereas female sex hormones and 5-HT(1A) receptors may interact to alter sucrose consumption in 5-HT(1A) mutant mice. In addition, these findings may have implications for the role of these receptors in the incidence and treatment of depression since the intake of sucrose has been used as an index of anhedonia in animal models of depression and antidepressant efficacy.

The present study investigated (1) whether consumption of a nibble-size snack, as compared to a bar-size snack, leads to more sensory specific satiety (SSS) and a lower intake; and (2) whether attention to consumption, as compared to usual consumption, leads to more SSS and a lower intake. Subjects (N=59) tested two snack foods which differed in size, nibbles and bars, in two consumption conditions. In the attention condition, the instruction to chew the food well was given. In the control condition no such instruction was given. For each of the four SSS sessions ad libitum intake was measured and SSS scores were calculated. Mean intake of the nibbles was 12% lower than of the bars in the control condition, but not in the attention condition. Although non-significantly, attention to consumption tended to reduce intake of the bars but not of the nibbles. SSS scores were slightly higher for the bars than for the nibbles. Our results suggest that a smaller food size results in a lower intake. The data do not clearly support the idea that attention to consumption decreases intake. Hypothetically consumption of small foods and attentive consumption prolong the oral sensory stimulation, which results in a lower intake.

The objective of this experiment was to evaluate the effect of feeding total mixed rations (TMR) that differ in structural and nonstructural carbohydrates to dairy cows in early and late lactation on short-term feed intake, dry matter intake (DMI), rumen fermentation variables, and milk yield. A 5 x 5 Latin square experiment with 15 dairy cows was repeated during early and late lactation. The 5 treatments were a TMR with ( all on dry matter basis) 55% roughage ( a 50: 50 mixture of corn silage and grass silage) and 45% concentrate ( a 50: 50 mixture of concentrate rich in structural carbohydrates and concentrate rich in nonstructural carbohydrates; treatment CON), a TMR with the concentrate mixture and 55% grass silage (RGS) or 55% corn silage (RCS), and a TMR with the roughage mixture and 45% of the concentrate rich in structural carbohydrates (CSC) or the concentrate rich in nonstructural carbohydrates (CNS). Meal criteria, determined using the Gaussian-Gaussian-Weibull method per animal per treatment, showed an interaction between lactation stage and treatment. Feed intake behavior variables were therefore calculated with meal criteria per treatment-lactation stage combination. Differences in feed intake behavior were more pronounced between treatments differing in roughage composition than between treatments differing in concentrate composition, probably related to larger differences in chemical composition and particle size between corn silage and grass silage than between the 2 concentrates. The number of meals was similar between treatments, but eating time was greater in RGS ( 227 min/d) and lesser in RCS ( 177 min/d) than the other treatments. Intake rate increased when the amount of grass silage decreased, whereas meal duration decreased simultaneously. These effects were in line with a decreased DMI of the RGS diet vs. the other treatments, probably related to the high neutral detergent fiber (NDF) content. However, this effect was not found in CSC, although NDF content of the TMR, fractional clearance rate of NDF, and fractional degradation rate of NDF was similar between CSC and RGS. Rumen fluid pH was lesser, and molar proportions of acetic acid and of propionic acid were lesser and greater, respectively, in RCS compared with all other diets. Milk production did not differ between treatments. There was no effect of type of concentrate on milk composition, but diet RCS resulted in a lesser milk fat content and greater milk protein content than diet RGS. Lactation stage did affect short-term feed intake behavior and DMI, although different grass silages were fed during early and late lactation. The results indicate that short-term feed intake behavior is related to DMI and therefore may be a helpful tool in optimizing DMI and milk production in high-production dairy cows.