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The present study evaluated the effects of feeding frequency (FF) and dietary protein/carbohydrate (P/CH) ratios on intestinal histomorphology, microbiota profile, and digestive and oxidative stress-related enzyme activities of gilthead seabream (Sparus aurata). To this purpose, two practical diets were formulated: one with 50% P and 10% CH (P50/CH10) and other with 40% P and 20% CH (P40/CH20). Triplicate groups of fish with9.1±0.01 gwere fed these diets for 60 days until visual satiation at a FF of 1, 2, or 3 meals per day. Distal intestine histomorphology was not affected by diet composition or FF. However, the pyloric caeca (PC) of fish fed 1 meal per day presented more gut fold height alterations than the other groups, except in fish fed diet P50/CH10 3 meals per day, where no changes was observed. Fish fed diet P40/CH20 3 meals per day also presented higher PC submucosa cellularity than the other groups. Fish fed diet P40/CH20 presented a higher number of operational taxonomic units, microbial richness, and diversity indices than fish fed diet P50/CH10. Amylase was the only measured digestive enzyme affected by the experimental conditions, presenting higher activity in fish fed diet P50/CH10 once per day. Glucose-6-phosphate dehydrogenase activity was lower in fish fed 2 meals per day than only 1. While catalase activity was lower in fish fed 2 than 3 meals per day. Glutathione reductase activity was the only measured parameter affected both by dietary P/CH ratio and FF, being inferior in fish fed once per day the P50/CH10 diet than the P40/CH20 diet and, also in the P50/CH10 diet, to fish fed 1 than those fed 3 meals per day. Overall, no major interactions was observed between dietary P/CH ratio and FF; however, a P40/CH20 diet fed 2 meals per day might be recommended for gilthead seabream juveniles.

Behavioural flexibility may play a relevant role during invasion of a new habitat. A typical example of behavioural flexibility favouring invasion success refers to changes in foraging behaviour. Here we provide data on changes in the foraging strategies of monk parakeets Myiopsitta monachus over a period of 17 years (2001–2017) in Barcelona city. During this time, consumption of food on the ground increased by more than 25 % and the consumption of anthropogenic food increased by 8 %. Detailed information about the food consumed is provided. Feeding on the ground and consumption of low plants allow parakeets to reach not only anthropogenic food but also crops, thereby increasing the risk of crop damage as the invasion evolves. Early detection of damage to crops is crucial in order to prevent further harm, and makes the precautionary principle highly relevant. Key words: Behavioural shift, Diet, Crop damage, Spillover, Longitudinal study

Can Roqueta has provided a large number of equid and dog assemblages from the Late Bronze Age to the Early Iron Age. An analysis of the stable isotopes δ13C and δ15N in 42 bone samples has made it possible to reconstruct the diet of domestic equids. The results and carpological remains show that the territory was managed for agricultural and pasture use. They indicate the cultivation of two types of highly nutritious and digestible millet, used in combination with other cereals to prepare fodder, as well as the use of natural pastures.

Knowledge of feeding ecology of declining species, such as farmland birds, is essential to address their conservation requirements, especially when their habitats are suffering important reductions of trophic resources. In this study, we apply a metabarcoding approach to describe the diet composition of six of the most significant farmland birds inhabiting European cereal pseudo-steppes: little bustard, great bustard, pin-tailed sandgrouse, black-bellied sandgrouse, red-legged partridge, and common quail. We further studied seasonal diet variations (autumn to spring) in all species but the common quail, whose diet was studied during spring and summer. We show that study species´ diets mostly consisted of plants, although in the case of little bustard and great bustard arthropods are also highly relevant. Among arthropods, we found high proportions of thrips, arachnids, and springtails, which were previously unreported in their diet, and some taxa that could be used as antiparasitic food. Moreover, we report that little bustard’s diet is the least rich of that of all studied species, and that diet of all these species is less diverse in winter than in autumn and spring. Diet composition of these declining species supports the importance of natural and semi-natural vegetation and landscape mosaics that can provide a wide variety of arthropods, plants, and seeds all year-round., This paper contributes to the REGRESSEDS project (CGL2016-75278-R funded by MINECO, Spain). This study is also a contribution to project Sistemática, Biogeografía, Ecología del comportamiento y Evolución (IT1163-19) funded by Basque Country Government. Additional funds for this study were provided by the projects 201630E096 funded by CSIC (recipient BA) and AGROPERDIZ (SBPLY/17/180501/ 000245) funded by the “Junta de Comunidades de Castilla-La Mancha” and “Fondo Europeo de Desarrollo Regional” (recipient FM & BA). Xabier Cabodevilla was supported by a Ph.D. grant, financed by the Basque Country Government (grant no. PRE_2018_2_0273).

The low breeding performance and body condition of nestling passerine birds in urban environments has been attributed to the poor quality and low abundance of food in these settings. However, detailed data on prey provided by parents to their chicks in the urban habitat is scarce. Here we used video cameras set in nest boxes to compare the diet of urban and forest great tits Parus major when provisioning their chicks in a Mediterranean area. We additionally analysed brood size and fledgling success. Breeding success of urban great tits was lower than that of forest birds. Urban parents displayed a lower average hourly feeding rate per nestling than forest parents. Among the three prey item categories, the percentage of spiders did not vary according to habitat. However, the percentage of caterpillars delivered to the nest by great tit parents was higher in the forest than in the urban habitat while the percentage of 'other' prey showed a reverse pattern. 'Other' prey were mainly adult butterflies and wasps in the urban habitat. Our paper adds to the view that the low feeding rates and scarcity of caterpillars in urban environments may be the underlying cause constraining the growth of great tit nestlings in these areas. Key words: Urbanization, Diet, Great tits, Parental provisioning, Prey composition, Prey size El escaso éxito reproductor y la condición física deficiente de los pollos de paseriformes en entornos urbanos se han atribuido a la escasez de alimentos en estos ambientes y a la mala calidad de estos. No obstante, existen pocos datos detallados sobre las presas que los progenitores llevan a sus pollos en el hábitat urbano. En este estudio, empleamos videocámaras instaladas en cajas nido con objeto de comparar la dieta que los carboneros comunes, Parus major, del medio urbano y forestal proporcionan a sus pollos en una zona del Mediterráneo. Asimismo, analizamos el tamaño de la nidada y el éxito de los volantones. El éxito reproductor de los carboneros comunes del medio urbano fue inferior al de las aves forestales. Se observó que la tasa media de alimentación por hora y por nidada de los progenitores del medio urbano fue inferior a la de los progenitores del medio forestal. Entre las tres categorías de presas, el porcentaje de arañas no varió en función del hábitat. Sin embargo, el porcentaje de orugas que los progenitores de carbonero común llevaron a los nidos fue mayor en el bosque que en el hábitat urbano, mientras que el porcentaje de "otras" presas mostró la pauta inversa. En el hábitat urbano, la categoría "otras" presas estuvo principalmente compuesta por mariposas y avispas adultas. Nuestro artículo se suma a la opinión de que las tasas de alimentación bajas y la escasez de orugas en los entornos urbanos pueden ser los factores que limitan el crecimiento de los pollos de carbonero común en estas zonas. Palabras clave: Urbanización, Dieta, Carboneros comunes, Aprovisionamiento parental, Composición de las presas, Tamaño de las presas

Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/pii/S0032579119480139?via%3Dihub#! The aim of the present study is to assess the effect of the dietary free fatty acid (FFA) content and dietary fat saturation degree on the fatty-acid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broiler chickens. The 8 experimental diets resulted from replacing crude soybean oil with soybean acid oil from chemical refining, or crude palm oil with palm FA distillate from physical refining. Thus, there were 4 soybean and 4 palm diets with 6% added fat varying in their FFA% (5, 15, 35, and 50%). Samples of digestive content (gizzard, duodenum, jejunum, and ileum) and excreta were collected at 14 D for the determination of the FA digestibility and lipid-class content. The total FA digestibility coefficients reported for the chickens fed S diets in the jejunum, ileum, and excreta were higher than for those fed P diets (P ≤ 0.02). The general greater digestibility of the unsaturated diets was mainly explained by a higher contribution of the ileum to the absorption of saturated FA. The dietary FFA content mainly affected the FA absorption process. The diets with 50% FFA presented lower saturated FA digestibility coefficients in the jejunum and ileum (P ≤ 0.03), and higher content of FFA in the ileum and excreta (P ≤ 0.014), in comparison to the diets with 5% FFA. The 15% FFA diets were not different from the 5% FFA diets, regarding the saturated FA digestibility in the jejunum and excreta, and the FFA content in the ileum and excreta. It was concluded that unsaturated diets with moderate content of dietary FFA (up to 15%) could be used in broiler-chicken starter diets, as they led to similar FA absorption and performance results to the diets with the lowest dietary FFA content. From the present study, it has also been concluded that dietary saturated FA content has a greater impact on FA absorption than the dietary FFA content has.

The aim of the present study is to evaluate the effect of the dietary fat saturation degree and age on the lipid class (TAG, DAG, MAG, and FFA) composition and fatty acid digestibility along the gastrointestinal tract (GIT) and excreta in broiler chickens. A total of 120 one-day-old female broiler chickens were randomly distributed in 2 dietary treatments (6 cages/treatment), which resulted from the supplementation of a basal diet with 6% of soybean oil or palm oil. Two digestibility balances were carried out at 14 and 35 d and fatty acid digestibility and lipid class composition were determined in the gizzard, duodenum, jejunum, ileum, and excreta. Along de GIT, both fatty acid digestibility and lipid class composition were influenced by the dietary fat source and the age of the chickens. The absorption of the unsaturated fat was more efficient and faster than it was for the saturated fat. The ability of adult chickens to absorb fat was higher than for young chickens. The results show that the duodenum is the main place of fat digestion (hydrolysis), and the jejunum the main place of fat absorption. The role of the ileum on fat absorption is very important, as it is the last segment of the GIT where the absorption of fatty acids has been described. Thus, it was the contribution of the ileum that was responsible for the higher fat utilization observed for animals fed the unsaturated diet than for those fed the saturated diet at 14 d, and it was also responsible for the improvement on the utilization of the saturated diet between 14 and 35 d. All the results suggest that the absorption of fatty acids is more limiting than is hydrolysis, because the main differences were observed in the jejunum and ileum, where the absorption of fatty acids takes place.

Acid oils (AO) and fatty acid distillates (FAD) are byproducts from chemical and physical refining of edible oils and fats, respectively. Their high energy value makes their upcycling interesting as alternatives to conventional fats in animal feeding. The objective of this study is to characterize their oxidative quality and to provide recommendations about their evaluation for animal feeding purposes. The oxidation status (peroxide value (PV), p-Anisidine value (p-AnV), % polymeric compounds (POL)), the oxidative stability (induction time by the Rancimat at 120 °C (IT)), the fatty acid composition (FA), and tocopherol and tocotrienol content of 92 AO and FAD samples from the Spanish market were analyzed. Both AO and FAD showed low PV (0.8 and 1 meq O2/kg), however, p-AnV was higher in FAD (36.4 vs. 16.4 in AO) and POL was higher in AO (2.5% vs. not detected in FAD) as a consequence of the type of refining process. The botanical origin of AO and FAD influenced FA and tocol composition, and they influenced IT. A high variability was observed for most analyzed parameters, reinforcing the need for standardizing AO and FAD to obtain reliable feed ingredients and to include primary and secondary oxidative parameters within their quality control.

[eng] Individual specialization refers to individuals using different portions of the total ecological niche of the population. The fact that individuals segregate into different strategies has important implications on ecology, evolution and conservation, which can be even greater than the implications associated to differences among species. Therefore, it is important to know the degree of individual specialization in wild populations and in what dimensions of individuals’ ecological niche it occurs. Similarly, to understand the processes underlying individual specialization, it is key to study intrinsic drivers and environmental conditions that lead individuals to segregate into different portions of the ecological niche. In this thesis, we aimed to delve into the extent of individual specialization in foraging and migration strategies, as well as to provide insights on the intrinsic and extrinsic drivers that shape it. We used two long-lived seabird species, Cory’s (Calonectris borealis) and Scopoli’s (C. diomedea) shearwaters, to study individual specialization in feeding and migratory traits by using stable isotope analyses, global location sensing (GLS) and global positioning system (GPS) loggers. In this thesis, we showed that individuals specialize in several aspects of the ecological niche, namely diet, foraging and wintering grounds, habitat use, daily habits and foraging movements. However, in none of these traits individuals showed high levels of specialization, thus suggesting a stabilizing selection in specialization levels. Regarding intrinsic drivers, our results elucidate that males and females can differ in their degree of individual specialization in diet and foraging movements. These differences were probably driven by a higher use of males on fishery discards. We also showed that the same individual can develop different strategies under different habitats, indicating individual foraging strategies are likely learned with experience when individuals are young and not driven by intrinsic constraints, such as physiological or morphological constraints. Regarding the extrinsic drivers, we provide evidences that resource scarcity is more relevant in driving among-individual variability in foraging movements than resource predictability. Overall, in this thesis we demonstrate that the extent of individual specialization within populations can depend on several intrinsic and extrinsic factors, and that individual specialization is a complex phenomenon that can vary across species and ecological traits. The fact that individuals can develop different strategies independently in different areas indicates a remarkable plasticity that may help them to cope with future natural or anthropogenic changes in the environment.

Fire is a major agent involved in landscape transformation and an indirect cause of changes in species composition. Responses to fire may vary greatly depending on life histories and functional traits of species. We have examined the taxonomic and functional responses to fire of eight taxonomic animal groups displaying a gradient of dietary and mobility patterns: Gastropoda, Heteroptera, Formicidae, Coleoptera, Araneae, Orthoptera, Reptilia and Aves. The fieldwork was conducted in a Mediterranean protected area on 3 sites (one unburnt and two burnt with different postfire management practices) with five replicates per site. We collected information from 4606 specimens from 274 animal species. Similarity in species composition and abundance between areas was measured by the Bray-Curtis index and ANOSIM, and comparisons between animal and plant responses by Mantel tests. We analyze whether groups with the highest percentage of omnivorous species, these species being more generalist in their dietary habits, show weak responses to fire (i.e. more similarity between burnt and unburnt areas), and independent responses to changes in vegetation. We also explore how mobility, i.e. dispersal ability, influences responses to fire. Our results demonstrate that differences in species composition and abundance between burnt and unburnt areas differed among groups. We found a tendency towards presenting lower differences between areas for groups with higher percentages of omnivorous species. Moreover, taxa with a higher percentage of omnivorous species had significantly more independent responses of changes in vegetation. High- (e.g. Aves) and low-mobility (e.g. Gastropoda) groups had the strongest responses to fire (higher R scores of the ANOSIM); however, we failed to find a significant general pattern with all the groups according to their mobility. Our results partially support the idea that functional traits underlie the response of organisms to environmental changes caused by fire. This study was partially supported by the “Conveni de Collaboració per al desenvolupament del Pla de gestió integral per a la conservació dels sistemes naturals de la Xarxa de Parcs Naturals” signed by Obra Social La Caixa and the Diputació de Barcelona, and by the projects CGL2011-29539 and Consolider Montes CSD2008-00040 granted by the Spanish Ministry of Education and Science (MEC). Xavier Santos is supported by a post-doctoral Grant (SFRH/BPD/73176/2010) from Fundação para a Ciência e a Tecnologia (FCT, Portugal).

The upward trend of seawater temperature has encouraged improving the knowledge of its consequences on fish, considering also the development of diets including vegetable ingredients as an approach to achieve a more sustainable aquaculture. This study aims to determine the effects on musculoskeletal growth of: (1) a high-water temperature of 28 &deg, C (versus 21 &deg, C) in gilthead sea bream juveniles (Sparus aurata) fed with a diet rich in palm oil and, (2) feeding the fish reared at 28 &deg, C with two other diets containing rapeseed oil or an equilibrated combination of both vegetable oils. Somatic parameters and mRNA levels of growth hormone-insulin-like growth factors (GH-IGFs) axis-, osteogenic-, myogenic-, lipid metabolism- and oxidative stress-related genes in vertebra bone and/or white muscle are analyzed. Overall, the data indicate that high-water rearing temperature in this species leads to different adjustments through modulating the gene expression of members of the GH-IGFs axis (down-regulating igf-1, its receptors, and binding proteins) and also, to bone turnover (reducing the resorption-activity genes cathepsin K (ctsk) and matrix metalloproteinase-9 (mmp9)) to achieve harmonic musculoskeletal growth. Moreover, the combination of palm and rapeseed oils seems to be the most beneficial at high-water rearing temperature for both balanced somatic growth and muscular fatty acid uptake and oxidation.

10 pages, 4 figures, 4 tables, supplementary data https://doi.org/10.1016/j.ecolind.2021.107943, For centuries, human activities have altered the population dynamics of wildlife. New anthropogenic food sources provide a predictable and abundant food supply that often induces very significant changes in the size, distribution, and behaviour of many populations, with ultimate consequences on the structure and functioning of natural ecosystems. Here, we combine historical and contemporary feather samples of a population of a superabundant, opportunistic predator, the yellow-legged gull Larus michahellis, to assess its trophic ecology and relate it to human activities in the long term. Dietary assessments were based on stable isotope analysis of carbon, nitrogen, and sulphur (δ13C, δ15N and δ34S), and were conducted through three end-point (marine prey, waste from landfills-slaughterhouses, and terrestrial invertebrates) Bayesian mixing models. Our results suggest that gulls’ diet showed a progressive decrease in the consumption of marine prey throughout the most recent period (late 20th century onwards), linked to an increase in the consumption of meat waste and small terrestrial invertebrates. Reported dietary changes over the sampling period correlated positively with the availability of marine resources around the breeding area. We provide evidence suggesting that the ability of gulls to exploit efficiently diverse anthropogenic food subsidies likely resulted in the exponential demographic increase of this population throughout the 20th century. In addition, current regulations affecting the availability of these food resources (e.g., fishing discards and landfill waste) likely reversed this trend over the last decade. Long-term evidence of population trophic plasticity, like the one we present here, is essential to implement and support management and conservation actions that limit the availability of anthropogenic resources, especially when it comes to superabundant, problematic species, This work was supported by FAU2008-00012-C02-01 from INIA (Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Spain), CGL2009-11278/BOS from Ministerio de Ciencia e Innovación from the Spanish Government, Fondos FEDER, 2017/2349 of the PLEAMAR programme with the collaboration of the Fundación Biodiversidad, from the Ministerio para la Transición Ecológica (Spain), cofounded by the EMFF (European Union), and REN2003-07050 Aplicación de biomarcadores a la gestión de una especie problemática (Larus cachinnans). CERCA Programme from Generalitat de Catalunya is also acknowledged. RR was supported by a postdoctoral Ramón y Cajal contract (RYC-2017-22055) and VMP was supported by a pre-doctoral contract BES-2014-068025 both from the Spanish Ministerio de Economía, Industria y Competitividad, With the institutional support of the ‘Severo OchoaCentre of Excellence’ accreditation (CEX2019-000928-S)

Este artículo se encuentra disponible en la siguiente URL: https://www.sciencedirect.com/science/article/pii/S0032579121002959?via%3Dihub The aim of the present study is to assess the effect of the free-fatty-acid (FFA) content and saturation degree of dietary fat (added at 6%) on the fattyacid (FA) digestibility and lipid-class content along the gastrointestinal tract and excreta in broilers from 22 to 37 d of age. This is essential to determine the potential use of acid oils (refining by-products rich in FFA) in broiler diets as an alternative to crude oils. The study consisted of a 2 £ 4 factorial arrangement, which included 2 fat sources (soybean oils − unsaturated, or palm oils − saturated) and 4 levels of FFA (5, 15, 35, and 50%). Samples of digestive content of the gizzard, duodenum, jejunum, ileum and of the excreta were obtained at 37 d of age. Irrespective of the dietary fat source, more than 80% of total FA (TFA) was absorbed in the jejunum. Broilers fed with unsaturated diets had a higher absorption efficiency of FA than did those fed with saturated diets. This conclusion is supported by the lower FFA content and the higher TFA and polyunsaturated FA (PUFA) digestibility coefficients in the ileum (P < 0.001) observed in the former group. The dietary FFA level did not affect the FA absorption process as much as the dietary fat source did. This was supported by the lack of statistical differences among the diets with a similar saturation degree but rather different levels of FFA, for TFA, saturated FA, and PUFA digestibility coefficients both in the jejunum and ileum. However, the interactions reported in the ileum for triacylglycerol and diacylglycerol contents (P < 0.001), as well as for monounsaturated FA digestibility coefficients (P < 0.05) show that the dietary FFA content affects the FA absorption process. The present results show that the inclusion of acid oils in grower-finisher broiler diets with FFA levels up to 35% does not have a negative impact on the FA absorption process.

Behavioral plasticity can drive feeding innovations, a frequent trait of urban exploiter species. The House Sparrow (Passer domesticus) is a widespread and abundant urban dweller whose success has often been related to its dietary breadth. Although both formal and informal sources (e.g., internet videos, news, and blogs) have shown meat scavenging behaviors of this sparrow, it has been overlooked in the literature. While it is recognized that this sparrow has a diverse diet in urban settings, quantitative sources report only 3 types of foods (i.e., seeds, plant origin, and invertebrates). Our field observation of a female House Sparrow feeding on a chicken “drumstick” (presumably fibula/tibia) leftover at a greenspace of Manhattan (i.e., High Line), USA, adds to the available formal and informal information regarding the opportunistic scavenging of dressed and cooked meat by these sparrows when available. Thus, our observation adds to the feeding plasticity knowledge of this urban-related invasive bird and suggests the importance of the role of pedestrians in molding House Sparrow diet. La plasticidad conductual es un factor que puede impulsar las innovaciones alimenticias, un rasgo frecuente de las especies explotadoras urbanas. El gorrión doméstico (Passer domesticus) es una especie muy prolifera en zonas urbanas, cuyo éxito se ha relacionado con su amplitud de dieta. Aunque existe evidencia formal e informal (e.g., videos, noticias y blogs) que muestra el comportamiento carroñero de este gorrión, ésta información se ha pasado por alto en la literatura. Si bien se reconoce que éste gorrión tiene una dieta amplia en entornos urbanos, la información cuantitativa sobre su alimentación únicamente incluye 3 tipos de alimentos (i.e., semillas, origen vegetal e invertebrados). En esta nota reportamos a una hembra de gorrión doméstico que se alimentaba de un sobrante de ‘‘pierna’’ de pollo (presumiblemente peroné / tibia) en un área verde de Manhattan (i.e., High Line), EE. UU. Nuestra observación se suma a la información formal e informal disponible sobre el comportamiento carroñero por parte de estos gorriones cuando está disponible. Por lo tanto, nuestra observación contribuye al conocimiento sobre la plasticidad alimentaria de esta ave invasora relacionada con la urbanización y sugiere la importancia del papel de los peatones en la dieta del gorrión doméstico.

Natural or human-induced environmental changes can modify the structure of ecological communities and thus alter food web interactions. After the collapse of hake stocks (Merluccius hubbsi) provoked by fisheries over the Patagonian shelf in 1997 profound changes have taken place in the community, including long-term dietary shifts in some marine vertebrate predators. Stable carbon (δ13C) and nitrogen (δ15N) isotope ratios in bone collagen of subadult and adult male South American fur seals (Arctocephalus australis) were measured for the period 1976–2017 to investigate if the changes occurred in the marine community from northern and central Patagonia affected the diet of this predator. Suess corrected δ13C values and δ15N values in bone collagen of fur seals did not change significantly over the study period. According to this, male fur seals have remained as pelagic foragers without changing their trophic position nor switching their main preys in the Patagonian food web over the last four decades. This long-term stability in the diet of fur seals contrasts with dietary changes reported for benthic foragers in the region. Although long-term diet studies are restricted to a few marine predators in the region, current evidence suggests that benthic-demersal foragers were more prone to dietary shifts than pelagic ones after perturbations that occurred in the marine community of northern and central Patagonia. Fil: Vales, Damián Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Cardona, Luis. Universidad de Barcelona; España Fil: Loizaga de Castro, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: García, Néstor A.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina Fil: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Centro Nacional Patagónico. Centro para el Estudio de Sistemas Marinos; Argentina

El Trabajo final de grado se ha hecho en colaboración con el Área Metropolitana de Barcelona (AMB) y la beca concedida del departamento de investigación en prevención de residuos. This project applies the Japanese methodology on the use of food surpluses for animal feed in the municipal markets of Barcelona. The volumes of fruits and vegetables wasted in Sant Antoni market have been quantified for four days (Wednesday, Thursday, Friday and Saturday). A total of 439.8 kg of fruit and vegetables waste were quantified. Extrapolating to all markets in Barcelona, it sums up to 13.54 tons per week of fruits and vegetables waste, of which 13.24 tons could be intended to produce a flour ingredient for pig feed. Furthermore, a management and transport system has been implemented for the food and vegetable waste. Considering that the flour making process has a yield of 13.6%, a total of 1.6 tons of flour could be produced within a week. As a conclusion, the municipal markets in Barcelona produce enough fruit and vegetable waste to implement this valorization system. El trabajo aplica una metodología japonesa sobre el uso de excedentes alimentarios para alimentación animal en los mercados municipales de Barcelona. Se han cuantificado los volúmenes de frutas y verduras que se han tirado en el mercado de Sant Antoni durante cuatro días (miércoles, jueves, viernes y sábado), sumando un total de 439,8 kg desperdiciados. La extrapolación a todos los mercados de Barcelona suma 13,54 toneladas semanales de excedentes de frutas y verduras, de los cuales 13,24 toneladas podrían ser destinados a elaborar un ingrediente harinoso para alimentación porcina. Teniendo en cuenta que el proceso de elaboración de la harina tiene un rendimiento del 13,6%, en una semana se podrían producir un total de 1,6 toneladas de harina de frutas y verduras. Con estos resultados, se concluye que los excedentes de frutas y verduras en los mercados son suficientemente elevados para implementar este sistema de valorización. El treball aplica una metodologia japonesa sobre l'ús d'excedents alimentaris per alimentació animal als mercats municipals de Barcelona. S'han quantificat els volums de fruites i verdures que es llencen del mercat de Sant Antoni durant quatre dies (dimecres, dijous, divendres y dissabte), sumant un total de 439,8 kg malbaratats. Una posterior extrapolació, per calcular els volums de fruites i verdures malbaratades a tots els mercats de Barcelona suma 13,54 tones setmanals d’excedents, dels quals 13,24 tones podrien ser destinats a la elaboració d'un ingredient farinós per alimentació porcina. A més a més s’ha implementat un sistema de gestió i transport dels excedents de fruites i verdures. Per tant, tenint en compte que el procés d’ elaboració de la farina té un rendiment del 13,6%, s’estima que en una setmana es podrien elaborar un total de 1,6 tones de farina de fruites i verdures. Es conclou, que els excedents de fruites i verdures als mercats són suficientment elevats per implementar aquest sistema de valorització. Objectius de Desenvolupament Sostenible::2 - Fam zero

[eng] Movement is a widespread characteristic in the animal kingdom —occurring at many spatiotemporal scales— with consequences at an individual, population, species, and even ecosystem level. It is a very diverse character, with many different drivers that stem from the way in which individuals interact with their environment. Of these, one of the most important is the distribution of resources, particularly for migratory and foraging movements. In migration, the search for an optimal environment involves movement at large spatiotemporal scales, following seasonal changes in resource distribution. In foraging movements, the search for resources happens at small spatiotemporal scales, and involves different strategies to optimise the search and capture of food, including the ability to obtain foraging cues from conspecifics. In seabirds, movement —at large and local scales— has deep repercussions in their life-history traits, evolutionary history, morphology, physiology and behaviour, which makes them a very valuable study group to understand the role, the causes and consequences of migratory and foraging movements in the ecology of marine top- predators. The study of migratory and foraging movements has been revolutionised by the development of smaller, cheaper and better tracking devices, promoting multi-colony, population and even species approaches to the study of animal movement, but which also come with a set of methodological challenges that have to be addressed in order to make unbiased inferences of space and habitat use at population or species level from individual movement data. In this thesis, we develop methods to test the possible biases introduced by the use of individual tracking data to infer distribution at a population or species level. we then apply these tools to a multi-colony dataset of non-breeding locations of Cory’s (Calonectris borealis), Scopoli’s (C. diomedea) and Cape Verde (C. edwardsii) shearwaters, to study their migratory connectivity and non-breeding habitat segregation at the colony, population and species level. Lastly, we apply state-of-the-art spatial models to study foraging distributions of three neighbouring colonies of Cory’s shearwaters, detect the segregation among them and unravel the environmental and behavioural drivers of this segregation. I developed several functions in the R environment aimed at the detection of the effects of individual site fidelity and temporal variability in the inference of spatial use at a colony or population level, and to calculate the degree in which the movements of a single population can be representative of those of the entire species. These tools are applicable to individual movement data regardless of the species or tracking device. we also used these tools to demonstrate the spatial and ecological segregation between the non-breeding distributions of three taxa of Calonectris shearwaters studied, as well as detecting a stronger degree of migratory connectivity at a population than at a colony level, indicating that individuals of different colonies within a population mix in the non-breeding areas, but birds from different populations do not, which has important implications for their population dynamics and for their conservation and management. Lastly, we demonstrated segregation among the foraging distributions of three neighbouring colonies of Cory’s shearwaters, both in the waters surrounding the colony and in distant, foraging grounds, finding evidences of both environmental and behavioural drivers behind this segregation, and suggesting a mechanism through which transfer of information between individuals can be shaping the distributions of foraging seabirds. The results of this thesis provide relevant tools for the field of movement ecology, as they can be used for analysing movements of mobile species, regardless of species, tracking device or spatiotemporal scale. In addition, they are relevant for the field of seabird ecology as they provide insights into the causes of space and habitat use in long-ranging pelagic seabirds., [cat] El moviment és una característica omnipresent en el regne animal, a les més diverses escales espacio-temporals i amb conseqüències a diferents nivells (individual,. poblacional, específic i fins i tot ecosistèmic). La força impulsora del moviment més predominant i generalitzada és distribució dels recursos en el medi, important tant a gran escala (moviments migratoris) com en els moviments diaris de recerca d’aliment a escala petita. En les aus marines en particular, el moviment té repercussions profundes en les seves característiques morfològiques i de comportament, en la seva història de vida, i la seva història evolutiva. El desenvolupament de dispositius de seguiment més petits, barats i precisos ha promocionat la proliferació d’estudis del moviment animal des d’un punt de vista multi- colònia, de població i fins i tot d’espècie. En aquesta tesi, desenvolupo diferents funcions per testar els biaixos introduïts en l’estudi del moviment, a través de dades de seguiment individual, a nivell de població o espècie. Posteriorment, utilitzo aquestes eines per a analitzar la connectivitat migratòria i la segregació dels hàbitats d’hivernada, des d’un punt de vista multi-colònia, de les baldrigues cendroses de l’Atlàntic (Calonectris borealis), del Mediterrani (C. diomedea), i de Cap Verd (C. edwardsii). Per últim, aplico un mètode innovador de modelatge espacial per a estudiar les distribucions d’alimentació de baldrigues cendroses de l’Atlàntic criant en tres colònies veïnes, per detectar-ne la segregació i descobrir-ne les causes, tant ambientals com comportamentals, incloent com els diferents mecanismes de transferència d’informació entre individus poden afectar a aquestes distribucions. Els resultats d’aquesta tesi tenen rellevància per a la ecologia del moviment en general, ja que són aplicables a dades de moviment individual de qualsevol espècie, independentment de l’aparell de seguiment utilitzat, i en el camp de l’ecologia de les aus marines, ja que proporciona nous coneixements sobre els diferents factors afectant la distribució i l’ús de l’espai, tant durant la cria com durant la hivernada, en aus pelàgiques.

A 90-d feeding trial was conducted in which five groups of gilthead seabream (11.96 g initial body weight) were fed with a microalgae-free diet (control group, C) or four diets containing the microalgae Nannochloropsis gaditana at two inclusion levels (2.5% or 5%), either raw (R2.5 and R5 batches) or cellulose-hydrolyzed (H2.5 and H5 batches), to study their effect on the body and muscle growth. At 40 days, the highest values of body length and weight were reached in R5 group, but at 64 and 90 days, these were reached in R2.5. However, feed conversion rate, specific growth, daily intake, and survival (100%) were similar in all the groups. The acquisition of a discoid body shape was accelerated depending on the inclusion level of N. gaditana in the diets. Moreover, H5 diet affected the fish geometric morphology compared to R5 diet. The white muscle transverse area was similar in all groups at 40 days, with the exception of H2.5 group, which showed the lowest area. At day 90, C and R2.5 displayed the highest muscle growth, attributable to increased hyperplasia in C, and higher hypertrophy in R2.5. However, the highest proportion of small and medium fibers was observed in R5 and H5, ALGAFISH, Evaluación de los efectos de las microalgas, incluidas en dietas de dorada, sobre el crecimiento, supervivencia y resistencia a infecciones., SI

Food is a main limiting factor for most populations. As a consequence, knowledge about the diet of invasive alien species determines the design of control measures. The Monk and Rose-ringed parakeets are two typical species of successful invasive parrots that are highly appreciated by people. Although some observations suggest that Monk parakeets rely on a higher percentage of anthropogenic food than Rose-ringed parakeets, no detailed quantitative data is available. The aim of this study was to compare the diet of the two parakeets using stable isotope analysis (SIA). We performed SIA of carbon and nitrogen in feathers collected in Barcelona, Spain. We also measured isotopic ratios for potential food sources. We reconstructed the diet of parakeets using Bayesian mixing models. The two species differed in the isotopic signatures of their feathers for both d13C and d15N. Diet reconstruction showed that Monk parakeets feed mainly on anthropogenic food (41.7%), herbaceous plants (26.9%) and leaves/seeds (22.2%), while Rose-ringed parakeets feed mainly on flowers/fruits (44.1%), anthropogenic food provided in the trap located at the museum (32.4%) and leaves/seeds (23.1%). The more detailed information we can obtain from the diet of these species is useful to develop more effective control measures for their populations. The Monk parakeet may be more susceptible to control through education local residents, given the greater use of anthropogenic food in this species compared to Rose-ringed parakeet. Our conclusions also indicate that SIA is a powerful tool in providing crucial information about the diet and informing measures to control invasive species. Key words: diet, stable isotopes, invasive species, Myiopsitta monachus, Psittacula krameri

Memoria de tesis doctoral presentada por Anna Arias Bulbena para obtener el título de Doctora en Ciencias Marinas por la Universitat de Barcelona (UB), realizada bajo la dirección del Dr. Albert Calbet Fabregat y del Dr. Enric Saiz Sendrós del Institut de Ciències del Mar (ICM-CSIC).-- 201 pages, figures, tables, supplementary material, annexes, [EN] Protistan grazers are a key component of marine planktonic food webs. These marine protists are the major grazers of pelagic primary production in the oceans and, therefore, they display a crucial role in marine biogeochemical cycles as pivotal intermediaries of the energy and mass flux from primary producers to higher trophic levels. Notwithstanding their relevant role in the global pelagic system, some key aspects related to their trophic behaviour remain still poorly understood. Among these features, diel feeding rhythms are of relevant importance as they represent the coupling between the cycles of primary production and the feeding cycles of their predators and, consequently, they strongly condition the carbon flux mediated by marine protistan grazers and the dynamics of planktonic food webs. This Ph.D. Thesis aims to deepen our knowledge of the diel feeding rhythms in marine protistan grazers, exploring their occurrence and the mechanisms that generate and modulate this rhythmic behaviour. Accordingly, we first investigated the existence of diel feeding rhythms in diverse species of heterotrophic and mixotrophic protistan grazers (the dinoflagellates Gyrodinium dominans, Oxyrrhis marina and Karlodinium armiger, and the ciliates Strombidium arenicola and Mesodinium rubrum). Then, we evaluated how intrinsic characteristics of the prey (Rhodomonas salina), including the growth phase and the diel variations on its stoichiometric composition, as well as own characteristics of the grazers, such as their previous feeding history and the timing for cell division, may be causal factors or perhaps regulate the diel feeding activity of marine protists. We also assessed the effect of extrinsic factors, such as the prey concentration, the light and the risk of predation, on the feeding rhythm of marine protists. Finally, we conducted field experimentation to study the diel feeding rhythms of protistan grazers in a natural ecosystem, the Gullmar Fjord (Sweden). As major conclusions of the present Ph.D. Thesis, we found that there might not exist a unique underlying mechanism causing the different patterns of diel feeding rhythms we observed in marine protistan grazers. Instead, it appears that marine protists species might have developed feeding rhythms largely conditioned by their physiological and behavioural characteristics, as well as by the ecological conditions from their original habitat, which might determine the factors by which it is modulated, [ES] Los ramoneadores protistas son un componente clave de las redes tróficas planctónicas marinas. Estos protistas marinos son los principales consumidores de producción primaria pelágica en los océanos y presentan, por lo tanto, un papel crucial en los ciclos biogeoquímicos marinos como intermediarios fundamentales de los flujos de energía y masa desde los productores primarios hacia niveles tróficos superiores. A pesar de su relevante papel en el sistema pelágico global, algunos aspectos clave relacionados con su comportamiento trófico son todavía poco conocidos. Entre estas características, los ritmos diarios de alimentación son de gran importancia, ya que representan el acoplamiento entre los ciclos de producción primaria y los ciclos de alimentación de sus depredadores y, en consecuencia, condicionan en gran medida el flujo de carbono mediado por los ramoneadores protistas marinos y la dinámica de las redes alimentarias planctónicas. Esta Tesis Doctoral tiene como objetivo profundizar en nuestro conocimiento de los ritmos de alimentación en los ramoneadores protistas marinos, estudiando su ocurrencia y los mecanismos que generan y modulan este comportamiento rítmico. Por ello, primeramente investigamos la presencia de ritmos diarios de alimentación en diversas especies de ramoneadores protistas heterotróficos y mixótrofos (los dinoflagelados Gyrodinium dominans, Oxyrrhis marina y Karlodinium armiger, y los ciliados Strombidium arenicola y Mesodinium rubrum). Luego, evaluamos como características intrínsecas de la presa (Rhodomonas salina), como son su fase de crecimiento y las variaciones diarias en su composición estequiométrica, así como también características propias de los ramoneadores, tales como su historia de alimentación previa y el momento de división celular, pueden ser factores causantes o bien reguladores de los ritmos diarios de alimentación en los protistas marinos. También investigamos el efecto de factores extrínsecos, como son la concentración de presas, la luz y el riesgo de depredación, sobre la actividad de alimentación rítmica de los protistas marinos. Finalmente, realizamos un estudio de campo sobre los ritmos de alimentación diarios de los ramoneadores protistas en un ecosistema natural, el Fiordo de Gullmar (Suecia). Como conclusiones principales de la presente Tesis Doctoral, encontramos que quizás no exista un mecanismo causal único que explique los diferentes patrones de ritmos diarios de alimentación en los ramoneadores protistas marinos. Nuestro estudio parece indicar que las especies de protistas marinos desarrollan ritmos diarios de alimentación condicionados, en gran medida, por sus características fisiológicas y de comportamiento, además de por las particularidades ecológicas de su hábitat de origen, las cuales determinarían los factores por los que este patrón de actividad puede ser modulado, [CAT] Els pastors protistes són un component clau de les xarxes alimentàries planctòniques marines. Aquests protistes marins constitueix el principal consumidor de la producció primària pelàgica en els oceans i presenta, per tant, un paper crucial en els cicles biogeoquímics marins com intermediaris fonamentals en els fluxos d'energia i de massa des dels productors primaris cap a nivells tròfics superiors. Tot i el seu rol rellevant en el sistema pelàgic global, alguns aspectes clau relacionats amb el seu comportament tròfic són encara poc coneguts. Entre aquestes característiques, els ritmes diaris d'alimentació són de gran importància, ja que representen l'acoblament entre els cicles de producció primària i els cicles d'alimentació dels seus depredadors i, en conseqüència, condicionen en gran manera el flux de carboni mediat pels pastors protistes marins i la dinàmica de la xarxa alimentaria planctònica. Aquesta Tesi Doctoral té com a objectiu aprofundir en el nostre coneixement sobre els ritmes d’alimentació diaris en els pastors protistes marins, estudiant la seva presencia i els mecanismes que generen i modulen aquest comportament rítmic. Així doncs, primerament vam investigar l’existència de ritmes diaris d’alimentació en diverses espècies de pastors protistes heterotròfics i mixòtrofs (els dinoflagel·lats Gyrodinium dominans, Oxyrrhis marina, i Karlodinium armiger, i els ciliats Strombidium arenicola i Mesodinium rubrum). Llavors, vam avaluar com característiques intrínseques de la presa (Rhodomonas salina), com són la fase de creixement i les variacions diàries en la seva composició estequiomètrica, així com també característiques pròpies dels pastors, com la seva història d’alimentació prèvia i el moment de divisió cel·lular, poden ser factors causants o bé reguladors dels ritmes diaris d’alimentació dels protistes marins. També vam avaluar l’efecte de factors extrínsecs, com són la concentració de presa, la llum i el risc de depredació, en l’activitat d’alimentació rítmica dels protistes marins. Finalment, vam portar a terme un estudi de camp per explorar els ritmes d’alimentació dels pastors protistes en un ecosistema natural (el Fiord de Gullmar, Suècia). Com a conclusions principals de la present Tesi Doctoral, vam trobar que potser no existeix un mecanisme causant únic dels ritmes diaris d’alimentació en pastors protistes marins. El nostre estudi sembla indicar que les espècies de protistes marins desenvolupen ritmes d’alimentació condicionats, en gran manera, per les seves característiques fisiològiques i de comportament, així com també de les particularitats ecològiques del seu hàbitat d’origen, les quals determinarien els factors pels quals el ritme és modulat, The present Ph.D. Thesis was carried out at the Institut de Ciències del Mar (CSIC) and it was developed in the framework of the FERMI project (CGL2014-59227-R). The author was financed by an FPI predoctoral fellowship (BES-2015-074092) funded by the Spanish Ministry of Science and Innovation (MICINN)

Diet to tissue discrimination factors for the blood and feathers of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri). Stable isotope analyses (SIAs) have been widely used in recent years to infer the diet of many species. This isotopic approach requires using diet to tissue discrimination factors (DTDFs) for each prey type and predator tissue, i.e., to determine the difference between the isotopic composition of the predator tissues and the different prey that conform its diet. Information on DTDF values in Psittaciformes is scarce. The aim of this study was to assess DTDF values for the carbon and nitrogen isotopes of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri), two invasive alien species of concern. We fed captive birds of the two parakeet species on a single–species diet based on sunflower seeds to establish the DTDFs for the blood and feathers. In the monk parakeet (N = 9) DTDFs were Δδ13C 2.14‰ ± 0.90 and Δδ15N 3.21‰ ± 0.75 for the blood, and Δδ13C 3.97‰ ± 0.90 and Δδ15N 3.67‰ ± 0.74 for the feathers. In the ring–necked parakeet (N = 9), the DTDFs were Δδ13C (‰) 2.58 ± 0.90 and Δδ15N (‰) 2.35 ± 0.78 for the blood, and Δδ13C 3.64‰ ± 0.98 and Δδ15N 4.10‰ ± 1.84 for the feathers. DTDF values for the ring–necked parakeet blood were significantly higher than those for the monk parakeet blood. No difference was found between the two species in the DTDF for feathers. Our findings provide the first values of DTDFs for blood and feathers in these parakeets, factors that are key to infer the diet of these species based on SIA. Key words: Stable isotopes, Parrots, Captive birds, Control diet, Invasive species Diet to tissue discrimination factors for the blood and feathers of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri). Stable isotope analyses (SIAs) have been widely used in recent years to infer the diet of many species. This isotopic approach requires using diet to tissue discrimination factors (DTDFs) for each prey type and predator tissue, i.e., to determine the difference between the isotopic composition of the predator tissues and the different prey that conform its diet. Information on DTDF values in Psittaciformes is scarce. The aim of this study was to assess DTDF values for the carbon and nitrogen isotopes of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri), two invasive alien species of concern. We fed captive birds of the two parakeet species on a single–species diet based on sunflower seeds to establish the DTDFs for the blood and feathers. In the monk parakeet (N = 9) DTDFs were Δδ13C 2.14‰ ± 0.90 and Δδ15N 3.21‰ ± 0.75 for the blood, and Δδ13C 3.97‰ ± 0.90 and Δδ15N 3.67‰ ± 0.74 for the feathers. In the ring–necked parakeet (N = 9), the DTDFs were Δδ13C (‰) 2.58 ± 0.90 and Δδ15N (‰) 2.35 ± 0.78 for the blood, and Δδ13C 3.64‰ ± 0.98 and Δδ15N 4.10‰ ± 1.84 for the feathers. DTDF values for the ring–necked parakeet blood were significantly higher than those for the monk parakeet blood. No difference was found between the two species in the DTDF for feathers. Our findings provide the first values of DTDFs for blood and feathers in these parakeets, factors that are key to infer the diet of these species based on SIA. Key words: Stable isotopes, Parrots, Captive birds, Control diet, Invasive species Diet to tissue discrimination factors for the blood and feathers of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri). Stable isotope analyses (SIAs) have been widely used in recent years to infer the diet of many species. This isotopic approach requires using diet to tissue discrimination factors (DTDFs) for each prey type and predator tissue, i.e., to determine the difference between the isotopic composition of the predator tissues and the different prey that conform its diet. Information on DTDF values in Psittaciformes is scarce. The aim of this study was to assess DTDF values for the carbon and nitrogen isotopes of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri), two invasive alien species of concern. We fed captive birds of the two parakeet species on a single–species diet based on sunflower seeds to establish the DTDFs for the blood and feathers. In the monk parakeet (N = 9) DTDFs were Δδ13C 2.14‰ ± 0.90 and Δδ15N 3.21‰ ± 0.75 for the blood, and Δδ13C 3.97‰ ± 0.90 and Δδ15N 3.67‰ ± 0.74 for the feathers. In the ring–necked parakeet (N = 9), the DTDFs were Δδ13C (‰) 2.58 ± 0.90 and Δδ15N (‰) 2.35 ± 0.78 for the blood, and Δδ13C 3.64‰ ± 0.98 and Δδ15N 4.10‰ ± 1.84 for the feathers. DTDF values for the ring–necked parakeet blood were significantly higher than those for the monk parakeet blood. No difference was found between the two species in the DTDF for feathers. Our findings provide the first values of DTDFs for blood and feathers in these parakeets, factors that are key to infer the diet of these species based on SIA. Key words: Stable isotopes, Parrots, Captive birds, Control diet, Invasive species

Este trabajo está vinculado al Proyecto OUTBIOTICS (POCTEFA-EFA 183-16), financiado por el Fondo Europeo de Desarrollo Regional Interreg POCTEFA 2014-2020. Se agradece el apoyo de Laboratorios ENOSAN en la realización de experimentos relacio-nados con el uso de nanopartículas de plata.

Cocoa is rich in polyphenols and methylxanthines, and it has been reported that its consumption, among other properties, has beneficial effects on metabolism. This study aimed to investigate the role of theobromine in cocoa’s metabolic properties in healthy rats. In addition to morphometric measurements, biochemical markers of lipids and glucose metabolism and gene expression of molecules related to immune cells in adipose and hepatic tissues were assessed after 7 or 18 days of diet. Additionally, a metabolomic analysis was carried out at day 7. This study revealed the presence of six discriminant metabolites in plasma due to the diets. Moreover, the results showed that theobromine is the main responsible factor for cocoa’s effects on body weight gain as well as on lipid and glucose metabolism. The effects on body weight and lipids appeared as early as after 7 days of diet, whereas those affecting glucose metabolism required a longer intervention.

Simple Summary Acid oils and fatty acid distillates are by-products from the edible oil refining industry that are rich in free fatty acids. Their use as feed ingredients is a way to valorize them in order to increase the sustainability of the food chain; however, differences in the animal productive parameters when using them have been reported. The objective of this study is their characterization and the identification of their sources of variability. Results have revealed a high variability in their composition, being influenced both by the botanical origin of de crude oil and by the type of refining process. Thus, the analytical control and standardization of these by-products is of outmost importance to guarantee a standardized quality which would increase their value as feed ingredients. Remarkably, almost all samples showed some compositional values above the limits recommended by some feed fat guidelines, which suggests that the production of these by-products must be standardized and improved, and some of the thresholds should probably be revised. Abstract Acid oils (AO) and fatty acid distillates (FAD) are oil refining by-products rich in free fatty acids. The objective of this study is their characterization and the identification of their sources of variability so that they can be standardized to improve their use as feed ingredients. Samples (n=92) were collected from the Spanish market and the MIU value (sum of moisture, insoluble impurities, and unsaponifiable matter), lipid classes, fatty acid composition, and tocol content were analyzed. Their composition was highly variable even between batches from the same producer. As FAD originated from a distillation step, they showed higher free fatty acid amounts (82.5 vs 57.0 g/100 g, median values), whereas AO maintained higher proportions of moisture, polymers, tri-, di-, and monoacylglycerols. Overall, the MIU value was higher in AO (2.60–18.50 g/100 g in AO vs 0.63-10.44 g/100 g in FAD), with most of the contents of insoluble impurities being higher than those in the guidelines. Tocol and fatty acid composition were influenced by the crude oil’s botanical origin. The calculated dietary energy values were, in general, higher for AO and decreased when a MIU correction factor was applied. The analytical control and standardization of these by-products is of the outmost importance to revalorize them as feed ingredients.

Behavioral plasticity can drive feeding innovations, a frequent trait of urban exploiter species. The House Sparrow (Passer domesticus) is a widespread and abundant urban dweller whose success has often been related to its dietary breadth. Although both formal and informal sources (e.g., internet videos, news, and blogs) have shown meat scavenging behaviors of this sparrow, it has been overlooked in the literature. While it is recognized that this sparrow has a diverse diet in urban settings, quantitative sources report only 3 types of foods (i.e., seeds, plant origin, and invertebrates). Our field observation of a female House Sparrow feeding on a chicken “drumstick” (presumably fibula/tibia) leftover at a greenspace of Manhattan (i.e., High Line), USA, adds to the available formal and informal information regarding the opportunistic scavenging of dressed and cooked meat by these sparrows when available. Thus, our observation adds to the feeding plasticity knowledge of this urban-related invasive bird and suggests the importance of the role of pedestrians in molding House Sparrow diet. La plasticidad conductual es un factor que puede impulsar las innovaciones alimenticias, un rasgo frecuente de las especies explotadoras urbanas. El gorrión doméstico (Passer domesticus) es una especie muy prolifera en zonas urbanas, cuyo éxito se ha relacionado con su amplitud de dieta. Aunque existe evidencia formal e informal (e.g., videos, noticias y blogs) que muestra el comportamiento carroñero de este gorrión, ésta información se ha pasado por alto en la literatura. Si bien se reconoce que éste gorrión tiene una dieta amplia en entornos urbanos, la información cuantitativa sobre su alimentación únicamente incluye 3 tipos de alimentos (i.e., semillas, origen vegetal e invertebrados). En esta nota reportamos a una hembra de gorrión doméstico que se alimentaba de un sobrante de ‘‘pierna’’ de pollo (presumiblemente peroné / tibia) en un área verde de Manhattan (i.e., High Line), EE. UU. Nuestra observación se suma a la información formal e informal disponible sobre el comportamiento carroñero por parte de estos gorriones cuando está disponible. Por lo tanto, nuestra observación contribuye al conocimiento sobre la plasticidad alimentaria de esta ave invasora relacionada con la urbanización y sugiere la importancia del papel de los peatones en la dieta del gorrión doméstico.

Los autores agradecen al Ministerio de Economía y Empresa (MINECO) del Gobierno de España la financiación recibida (proyectos AGL2014-55379, AGL2017-87755-R y RTC-2015-3508-2 Una forma de hacer Europa).

[spa] Los hábitats utilizados por las tortugas marinas durante su desarrollo varían notablemente en cuanto a características ambientales y disponibilidad de alimento. Comprender los factores que determinan la selección del hábitat y de la dieta resulta esencial para comprender la interacción que existe entre dichas especies y sus hábitats. Dicho conocimiento también proporciona datos para adoptar medidas de gestión y conservación destinadas a restaurar y mantener las poblaciones de tortugas marinas y así, su función ecológica en el ecosistema. Las zonas costeras de Brasil, Uruguay y Argentina albergan diversos hábitats de importancia para la alimentación de los juveniles de la tortuga verde, pero todavía existe un gran desconocimiento sobre la ecología trófica de esta especie durante la fase juvenil de transición desde hábitats pelágicos a bentónicos. En esta tesis se ha estudiado cómo se produce el asentamiento de las tortugas verdes en la costa de Brasil, incluyendo la selección del hábitat y la adquisición de un microbioma adecuado para la digestión de material vegetal. Los resultados demuestran que el asentamiento de las tortugas verdes a lo largo de la costa oriental de Sudamérica está fuertemente influido por la corriente del Brasil y que el cambio ontogenético es rápido en las zonas tropicales y más lento en las subtropicales, a pesar de la rápida adquisición de una microbiota capaz de degradar polisacáridos complejos en ambas zonas. Dicha microbiota resulta en una gran eficiencia en la digestión de algas, especialmente de las Rodophyta, pero no impide la digestión de presas animales. Por último, las tortugas juveniles seleccionan de forma preferente para su alimentación zonas de arrecife de baja rugosidad, someras y con poco coral vivo., [eng] The habitats used by marine turtles during their development vary largely in environmental conditions and food availability. Understanting habitat selection is critical to the implementation of successful management and conservation actions aiming to restore and maintain sea turtle populations and, thus, their ecological function in the ecosystem. The coastal areas of Brazil, Uruguay and Argentina have a diversity of coastal habitats supporting feeding grounds for the green turtle, but there is still a lack of knowledge about the feeding ecology of this species during the juvenile transition phase from pelagic habitats to neritic habitats. This thesis has studied the settlement of green turtles in the coastal habitats of Brazil, including the ontogenetic diet shift. Results show that the settlement of green turtles along the eastern coast of South America is strongly influenced by the Brazilian current and that the ontogenetic change is fast in the tropics and slower in the subtropics, despite a fast acquisition of a microbiota capable of fermenting complex polysaccharides shortly after settlement. Such microbiome is highly efficient for the digestion of macroalgae, particularly Rodophyta, but does not impede the digestion of animal matter. Finally, preferred foraging grounds are shallow, have a low rugosity and little live coral.

espanolLos analisis de isotopos estables se han venido utilizando de forma generalizada en los ultimos anos para inferir la dieta de numerosas especies. El metodo isotopico consiste en utilizar factores de discriminacion entre la dieta y los tejidos para cada tipo de presa y tejido de depredador, es decir, determinar la diferencia entre la composicion isotopica de los tejidos del depredador y la de las distintas presas que integran su dieta. Hay muy poca informacion sobre los valores de los factores de discriminacion entre la dieta y los tejidos relativa a los psitaciformes. La finalidad de este estudio fue evaluar los valores de los factores de discriminacion de los isotopos de carbono y nitrogeno de la cotorra argentina (Myiopsitta monachus) y la cotorra de Kramer (Psittacula krameri), que son dos especies exoticas invasivas motivo de preocupacion. Alimentamos a aves en cautividad de las dos especies de cotorra con una dieta exclusivamente a base de semillas de girasol para establecer los factores de discriminacion relativos a la sangre y las plumas. En la cotorra argentina (N = 9), los factores de discriminacion para la sangre fueron: Δδ13C 2,14 ‰ ± 0,90 y Δδ15N 3,21 ‰ ± 0,75 y para las plumas: Δδ13C 3,97 ‰ ± 0,90 y Δδ15N 3,67 ‰ ± 0,74. Los factores de discriminacion de la cotorra de Kramer (N = 9) para la sangre fueron: Δδ13C (‰) 2,58 ± 0,90 y Δδ15N (‰) 2,35 ± 0,78 y para las plumas: Δδ13C 3,64 ‰ ± 0,98 y Δδ15N 4,10 ‰ ± 1,84. Los valores de los factores de discriminacion entre la dieta y la sangre de la cotorra de Kramer fueron significativamente mas elevados que los de la cotorra argentina. Con respecto a las plumas, no se observaron diferencias entre las dos especies. Nuestros resultados proporcionan los primeros valores de los factores de discriminacion para la sangre y las plumas en cotorras, que son fundamentales para inferir la dieta de estas especies mediante el analisis de isotopos estables. EnglishStable isotope analyses (SIAs) have been widely used in recent years to infer the diet of many species. This isotopic approach requires using diet to tissue discrimination factors (DTDFs) for each prey type and predator tissue, i.e., to determine the difference between the isotopic composition of the predator tissues and the different prey that conform its diet. Information on DTDF values in Psittaciformes is scarce. The aim of this study was to assess DTDF values for the carbon and nitrogen isotopes of the monk parakeet (Myiopsitta monachus) and the ring–necked parakeet (Psittacula krameri), two invasive alien species of concern. We fed captive birds of the two parakeet species on a single–species diet based on sunflower seeds to establish the DTDFs for the blood and feathers. In the monk parakeet (N = 9) DTDFs were Δδ13C 2.14 ‰ ± 0.90 and Δδ15N 3.21 ‰ ± 0.75 for the blood, and Δδ13C 3.97 ‰ ± 0.90 and Δδ15N 3.67 ‰ ± 0.74 for the feathers. In the ring–necked parakeet (N = 9), the DTDFs were Δδ13C (‰) 2.58 ± 0.90 and Δδ15N (‰) 2.35 ± 0.78 for the blood, and Δδ13C 3.64 ‰ ± 0.98 and Δδ15N 4.10 ‰ ± 1.84 for the feathers. DTDF values for the ring–necked parakeet blood were significantly higher than those for the monk parakeet blood. No difference was found between the two species in the DTDF for feathers. Our findings provide the first values of DTDFs for blood and feathers in these parakeets, factors that are key to infer the diet of these species based on SIA.

Ghrelin is involved in the regulation of growth in vertebrates through controlling different functions, such as feed intake, metabolism, intestinal activity or growth hormone (Gh) secretion. The aim of this work was to identify the sequences of preproghrelin and Ghrelin receptors (ghsrs), and to study their responses to different nutritional conditions in gilthead sea bream (Sparus aurata) juveniles. The structure and phylogeny of S. aurata preproghrelin was analyzed, and a tissue screening was performed. The effects of 21 days of fasting and 2, 5, 24 h, and 7 days of refeeding on plasma levels of Ghrelin, Gh and Igf-1, and the gene expression of preproghrelin, ghsrs and members of the Gh/Igf-1 system were determined in key tissues. preproghrelin and the receptors are well conserved, being expressed mainly in stomach, and in the pituitary and brain, respectively. Twenty-one days of fasting resulted in a decrease in growth while Ghrelin plasma levels were elevated to decrease at 5 h post-prandial when pituitary ghsrs expression was minimum. Gh in plasma increased during fasting and slowly felt upon refeeding, while plasma Igf-1 showed an inverse profile. Pituitary gh expression augmented during fasting reaching maximum levels at 1 day post-feeding while liver igf-1 expression and that of its splice variants decreased to lowest levels. Liver Gh receptors expression was down-regulated during fasting and recovered after refeeding. This study demonstrates the important role of Ghrelin during fasting, its acute down-regulation in the post-prandial stage and its interaction with pituitary Ghsrs and Gh/Igf-1 axis., The authors thank the personnel from the animal facilities at the School of Biology for the fish maintenance and to Piscimar for providing the fish. We also thank Prof. Jordi Garcia for his help on sequence analysis and primer design of Ghsrs. MP-A, EV, and NR-H are supported by predoctoral fellowships from the Ministerio de Economía y Competitividad (MINECO) BES-2016-078697, BES-2013-062949 and BES-2015-074654, respectively. This study was supported by the projects from the MINECO AGL2014-57974-R to IN and EC. and AGL2015-70679-R to JG, and the Xarxa de Referència d'R+D+I en Aqüicultura and the 2014SGR-01371 from the Generalitat de Catalunya.

Previous studies have demonstrated that cocoa intake decreased Th2 immune-related antibodies in rats. In consequence, we aimed to study in depth this cocoa action, particularly assessing its effect on a rat model of food allergy (FA) and also on an anaphylactic response. The involvement of the intestinal immune system was analyzed to allow the action mechanisms to be investigated. The role of cocoa flavonoids in the anti-allergic properties of cocoa was also established. Brown Norway rats were fed either a reference diet or diets containing conventional cocoa (CC) or non-fermented cocoa (NFC). FA to ovalbumin (OVA) was induced and, later, an anaphylactic response was provoked. As expected, the synthesis of anti-OVA IgE and other Th2-related antibodies was inhibited by CC diet. In addition, the release of mast cell protease II after anaphylaxis was partially prevented by CC, although other variables were not modified. The CC diet also attenuated the increase of some Th2-related cytokines released from mesenteric lymph node and spleen cells, and modulated the intestinal gene expression of molecules involved in allergic response. These results demonstrated the local and systemic influence of CC diet. The effects of the NFC diet were weaker than those of CC, suggesting that cocoa components other than flavonoids play a role in cocoa's action. In conclusion, by acting on intestinal and systemic immune functions, a cocoa-enriched diet in rats exhibited a protective effect against FA and partially against anaphylaxis, making this a food of high interest to the fields of health and immunonutrition.

Background: Identifying the factors that affect ranging behavior of animals is a central issue to ecology and an essential tool for designing effective conservation policies. This knowledge provides the information needed to pre- dict the consequences of land-use change on species habitat use, especially in areas subject to major habitat trans- formations, such as agricultural landscapes. We evaluate inter-individual variation relative to environmental predictors and spatial constraints in limiting ranging behavior of female little bustards (Tetrax tetrax) in the non-breeding season. Our analyses were based on 11 females tracked with GPS during 5 years in northeastern Spain. We conducted devi- ance partitioning analyses based on different sets of generalized linear mixed models constructed with environmen- tal variables and spatial filters obtained by eigenvector mapping, while controlling for temporal and inter-individual variation. Results: The occurrence probability of female little bustards in response to environmental variables and spatial filters within the non-breeding range exhibited inter-individual consistency. Pure spatial factors and joint spatial-habitat factors explained most of the variance in the models. Spatial predictors representing aggregation patterns at ~ 18 km and 3-5 km respectively had a high importance in female occurrence. However, pure habitat effects were also identi- fied. Terrain slope, alfalfa, corn stubble and irrigated cereal stubble availability were the variables that most contrib- uted to environmental models. Overall, models revealed a non-linear negative effect of slope and positive effects of intermediate values of alfalfa and corn stubble availability. High levels of cereal stubble in irrigated land and roads had also a positive effect on occurrence at the population level. Conclusions: Our results provide evidence that female little bustard ranging behavior was spatially constrained beyond environmental variables during the non-breeding season. This pattern may result from different not mutually exclusive processes, such as cost-benefit balances of animal movement, configurational heterogeneity of environ- ment or from high site fidelity and conspecific attraction. Measures aimed at keeping alfalfa availability and habitat heterogeneity in open landscapes and flat terrains, in safe places close to breeding grounds, could contribute to protect little bustard populations during the non-breeding season.

[spa] Actualmente, uno de los principales objetivos en la acuicultura está dirigido a minimizar la cantidad de proteína en la dieta suministrada a los peces carnívoros en cultivo y reemplazarla, parcialmente, por carbohidratos y nutrientes más económicos de origen no marino, los cuales cubrirían las necesidades energéticas. La finalidad de estos estudios es determinar si es posible realizar una intervención biotecnológica sobre GDH para reducir parte de la proteína de la dieta que los peces destinan a fines energéticos, teniendo en cuenta que GDH desempeña un papel fundamental en el metabolismo de los aminoácidos para obtener energía y proveer sustratos gluconeogénicos. Esta intervención podría contribuir, por una parte, a reducir el coste de la producción de peces en cultivo, y por otro, a la disminución de la eutrofización de las aguas causada por el incremento en la excreción de compuestos nitrogenados procedentes de la utilización de los aminoácidos como fuente de energía. De esta manera, se intenta forzar a que estos organismos utilicen fuentes alternativas de energía, como los carbohidratos, y por lo tanto reducir la cantidad de proteínas que es necesario suministrar a los peces en cultivo. Asimismo, nos planteamos estudiar la regulación transcripcional del promotor de gen gdh, así como, analizar la distribución tisular y estudiar el control nutricional a que está sujeta la expresión de GDH. Adicionalmente, nos planteamos avanzar en el conocimiento de la función celular que desempeña GDH, así como los efectos metabólicos que podría ejercer una inhibición transitoria de la expresión del ARNm que codifica para la enzima GDH en el hígado de S. aurata utilizando la técnica de silenciación génica a través del diseño de shARNs (short-hairpin ARNs). Ensayos de retardación en gel y de transfección transitoria de células HepG2 con constructos reporteros delecionados y mutados indican que USF2 transactiva el promotor del gen gdh de S. aurata a través de la unión a la secuencia E-box localizada entre las posiciones -10 a -5 en sentido ascendente desde el inicio de la transcripción. El análisis de la expresión del ARNm hepático de GDH y USF2 disminuye significativamente en peces sometidos a ayuno prolongado con respecto a los valores observados en peces alimentados. Además, siguieron el mismo patrón de expresión después de una realimentación a corto y largo plazo. La silenciación génica de GDH en hígado de S. aurata disminuye la expresión de la actividad FBPasa-1 sin afectar a la de PFK-1, favoreciendo por lo tanto el flujo glucolítico respecto al gluconeogénico a nivel del ciclo de sustrato fructosa-6- fosfato/fructosa-1,6-bisfosfato. También promueve el aumento de la concentración de α- cetoglutarato, sustrato de GDH en su actividad reductora, así como de la actividad del complejo OGDH, clave en el control del flujo del ciclo de Krebs. Además, los niveles de glutamato y glutamina, altamente dependientes de glutamato, también descendieron en el hígado de doradas sometidas a silenciación génica de GDH. Los resultados obtenidos permiten concluir que la silenciación de la expresión de GDH en hígado de S. aurata podría ser una diana de interés para favorecer la utilización de los carbohidratos de la dieta como sustrato energético y promover así un efecto de ahorro de proteínas, que permitiría reducir los costos de producción y reducir el impacto ambiental de la acuicultura., [eng] A main goal in aquaculture is aimed at minimizing the amount of protein in the diet supplied to carnivorous fish in culture and to replace it, at least partially, with cheaper nutrients, such as carbohydrates and nutrients from non-marine sources, to cover energy needs. The purpose of these studies is to determine whether it is possible to carry out a biotechnological action on GDH expression, which play a fundamental role in amino acid catabolism and provision of gluconeogenic substrates, to facilitate reduction of dietary protein allocated for energy production and favor the use of alternative nutrients. This could contribute, on the one hand, to reduce the cost of fish production in aquaculture, and on the other hand, to decrease excretion of nitrogen compounds and contamination of local waters. We cloned and charactized transcriptional regulation of the GDH gene promoter, as well as analyzed tissue distribution and nutritional regulation of GDH expression. These studies allowed us to identify USF2 as a key transcription factor involved in control of GDH expression. Additionally, we progressed in the knowledge of the molecular function exerted by GDH by performing transient inhibition of the expression of GDH mRNA in the liver of S. aurata by means of promoting a gene silencing through the design of a specific short hairpin RNA (shRNA). GDH silencing favored glycolysis over gluconeogenesis in the piscine liver. The results obtained allowed us to conclude that silencing of the expression of GDH in the liver of S. aurata could be a biotechnological target of interest to favor the use of dietary carbohydrates to produce energy and promote a protein sparing effect, which would allow reduction of the production cost and the environmental impact of aquaculture.

Studying the feeding ecology of seabirds is important not only to understand basic aspects of their ecology and threats but also for the conservation of marine ecosystems. In this regard, tropical seabirds have been relatively neglected, and in particular the trophic ecology of tropicbirds is scarcely known. We combined GPS tracking, environmental variables and sampling of regurgitates during incubation and brooding to understand the feeding ecology of red-billed tropicbirds Phaethon aethereus as well as how foraging strategies may change between 2 contrasting marine environments: a coastal island in the Canary Current upwelling (Îles de la Madeleine) and an oceanic island in the middle of the south Atlantic (St Helena). Tropicbirds breeding on the Îles de la Madeleine headed west, foraging on and beyond the shelf slope, probably to associate with subsurface predators which bring pelagic fish close to the surface. Birds from St Helena showed a greater foraging effort and a strong attraction to areas with the greatest species richness of Scombridae, possibly due to a greater difficulty in finding prey in the oligotrophic oceanic waters. Tropicbirds ranged much beyond the extension of the protected areas around their colonies, indicating that current protected areas are insufficient for these populations. We found no evidence to suspect direct mortality of tropicbirds in regional fisheries, but overexploitation of small epipelagic fish and tuna may decrease feeding opportunities and lead to competition with fisheries. The substantial differences in foraging behaviour demonstrated by individuals from both colonies indicates that caution should be taken when extrapolating foraging patterns of tropical seabirds breeding in contrasting oceanographic environments.

[ES] El principal objetivo de este trabajo fue evaluar el efecto sobre el coeficiente de digestibilidad aparente de la materia seca (MS), energía bruta (EB), proteína bruta (PB) y de las fracciones fibrosas, al variar la fuente de la fibra añadida a las dietas de futuras cerdas reproductoras. Para ello, se utilizaron 8 piensos en un diseño factorial 4x2 (4 tipos de fibra e inclusión o no de enzimas), aunque para este trabajo por cuestiones prácticas se considerará únicamente el efecto del tipo de fibra. Como fuentes de fibra, se utilizaron: fuentes de glucosa insoluble-celulosa (fórmula de base maíz con girasol y soja), fuentes de manosa (fórmula de base maíz con colza y palmiste), fuentes de glucanos (formula de base cebada con girasol y soja) y fuentes de arabinoxilanos solubles (fórmula de base trigo, salvado de arroz y germen de maíz con girasol y soja). Se utilizaron 12 cerdas vacías con un peso vivo inicial de 123,2±8,33 kg. Los animales se alojaron en jaulas de digestibilidad durante 8 periodos experimentales de 2 semanas de duración cada uno: 10 días de adaptación a los piensos experimentales y 4 días de recogida de muestras. Los animales se pesaron al inicio y final de cada periodo, y durante todo el periodo experimental se controló el consumo de pienso. Durante los 4 días de recogida el total de heces producidas se recogió y pesó cada 24 h. A partir de las muestras de pienso, se analizó la MS, cenizas, PB, extracto etéreo (EE), fibra bruta (FB), almidón (AL), la Fibra Neutro Detergente (FND), Fibra Ácido Detergente (FAD), Lignina (LAD), Fibra Dietaria Total (FDT), Fibra Dietaria Soluble (FDS), la proteína ligada a fibra y la EB. A partir de las muestras de heces individuales recogidas durante el balance de digestibilidad, se analizó la EB, MS y PB. A partir de un pool de heces por tratamiento, se realizaron las determinaciones de MS, EE, FND, FAD y FDT. No existieron diferencias significativas en el peso vivo y el consumo medio diario entre los diferentes piensos. La composición analizada de los piensos fue similar a la calculada. Sin embargo, se encontró un efecto claro del tipo de pienso sobre los coeficientes de digestibilidad aparente de la MS, EB y PB (P, [EN] The main objective of this work was to evaluate the effect of the source of fiber on the apparent digestibility coefficients of dry matter (DM), gross energy (GE), crude protein (CP) and fiber fractions in future breeding sows. Eight dietary treatments in a 4x2 factorial design (four types of fiber and inclusion or not of enzymes) were used. For practical reasons in this research only the effect of fiber type was considered. As a source of fiber glucose insoluble-cellulose (corn, sunflower and soya diet), mannose (corn, rapeseed and palm kernel diet), glucan (barley, sunflower and soya diet) and arabinoxylans (wheat, rice brand and corn germ whit sunflower and soya) diets were tested. Twelve sows 123,2±8,33 kg initial live weight were used. The animals were housed in digestibility cages for eight experimental periods, two weeks each: ten days for experimental feed adaptation, and four days of feces collection. The animals were weighed at the beginning and at the end of each period. Throughout the whole experimental period, animal weight was controlled. During the 4 days of feces collection, the total amount of feces were collected and weighted each 24 hours. Feed samples were analyzed for DM, ash, CP, ether extract (EE), crude fiber, starch, neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, total dietary fiber (TDF), soluble dietary fiber, the fiber-bound protein and GE. The individual sample feces collected were analyzed for DM, CP and GE. Feces were polled by treatment and each pool were analyzed for DM, EE, NDF, ADF and TDF, as well. No statistical significant differences were found in animal live weight and average daily consumption between treatments during the experimental period. The analyzed diet composition was similar to the estimated. There was a significant effect of the fiber type on DM, GE and CP (P, [CA] L’objectiu d’aquest treball es avaluar l’efecte sobre el coeficient de digestibilitat aparent de la matèria seca (MS), energia bruta (EB), proteïna bruta (PB) i de les fraccions fibroses, al variar les fonts de fibra en pinsos de porques reproductores. Per això, es van utilitzar 8 pinsos en un disseny factorial 4x2 (4 tipus de fibra e inclusió o no d’enzims), encara que per a aquest treball per qüestions pràctiques es considerarà únicament l’efecte del tipus de fibra. Com a fonts de fibra, es van utilitzar: fonts de glucosa insoluble-cel·lulosa (fórmula de base dacsa amb gira-sol i soja), fonts de manosa (fórmula de base dacsa amb colza i palmiste), fonts de glucans (fórmula de base d’ordi amb girasol i soja) y fonts d’arabinoxilans solubles (fórmula de base trigo, segó d’arròs i germen de dacsa amb gira-sol i soja). Es van utilitzar 12 porques buides amb un pes viu inicial de 123,2±8,33 kg. Els animals es van allotjar en gàbies de digestibilitat durant 8 períodes experimentals de 2 setmanes de duració cada u: 10 dies d’adaptació als pinsos experimentals i 4 dies de recollida de mostres. Els animals es pesaren a l’inici i al final de cada període i durant tot el període experimental es va controlar el consum de pinso. Durant els 4 dies de recollida el total de excrements produïts se va recollir i pesar cada 24 h. A partir de les mostres de pinso, s’analitzà la MS, cendres (cen), PB, extracte eteri (EE), fibra bruta (FB), midó (AL), la Fibra Neutra Detergent (FND), Fibra Àcid Detergent (FAD), Lignina (LAD), Fibra Dietaria Total (FDT), Fibra Dietaria Soluble (FDS) y la proteïna lligada a fibra. A partir de les mostres d’excrements individuals recollits durant el balanç de digestibilitat, s’analitzà la EB, MS i PB. A partir d’un pool d’excrements per tractament, es realitzaren les determinacions de MS, EE, FND, FAD i FDT. No van existir diferencies significatives en el pes viu i el consum medi diari (CMD) entre els diferents pinsos. La composició analitzada dels pinsos fou similar a la calculada. No obstant això, es va trobar un efecte clar del tipus de pinso sobre los coeficients de digestibilitat aparent de la MS, EB i PB (P

Spring sea ice phenology regulates the timing of the two consecutive pulses of marine autotrophs that form the base of the Arctic marine food webs. This timing has been suggested to be the single most essential driver of secondary production and the efficiency with which biomass and energy are transferred to higher trophic levels. We investigated the chronological sequence of productivity pulses and its potential cascading impacts on the reproductive performance of the High Arctic seabird community from Svalbard, Norway. We provide evidence that interannual changes in the seasonal patterns of marine productivity may impact the breeding performance of little auks and Brünnich’s guillemots. These results may be of particular interest given that current global warming trends in the Barents Sea region predict one of the highest rates of sea ice loss within the circumpolar Arctic. However, local- to regional-scale heterogeneity in sea ice melting phenology may add uncertainty to predictions of climate-driven environmental impacts on seabirds. Indeed, our fine-scale analysis reveals that the inshore Brünnich’s guillemots are facing a slower advancement in the timing of ice melt compared to the offshore-foraging little auks. We provide a suitable framework for analyzing the effects of climate-driven sea ice disappearance on seabird fitness

The addition of some fat co- and by-products to feeds is usual nowadays; however, the regulations of their use are not always clear and vary between countries. For instance, the use of recycled cooking oils is not allowed in the European Union, but they are used in other countries. However, oils recovered from industrial frying processes could show satisfactory quality for this purpose. Here we studied the effects of including oils recovered from the frying industry in rabbit and chicken feeds (at 30 and 60 g/kg, respectively) on the fatty acid (FA) and tocol (tocopherol + tocotrienol) compositon of meat, liver and plasma, and on their oxidative stability. Three dietary treatments (replicated eight times) were compared: fresh non-used oil (LOX); oil discarded from the frying industry, having a high content of secondary oxidation compounds (HOX); and an intermediate level (MOX) obtained by mixing 50 : 50 of LOX and HOX. The FA composition of oil diets and tissues was assessed by GC, their tocol content by HPLC, the thiobarbituric acid value was used to assess tissue oxidation status, and the ferrous oxidation-xylenol orange method was used to assess the susceptibility of tissues to oxidation. Our results indicate that FA composition of rabbit and chicken meat, liver and plasma was scarcely altered by the addition of recovered frying oils to feed. Differences were encountered in the FA composition between species, which might be attributed mainly to differences in the FA digestion, absorption and metabolism between species, and to some physiological dietary factors (i.e. coprophagy in rabbits that involves fermentation with FA structure modification). The α-tocopherol (αT) content of tissues was reduced in response to the lower αT content in the recovered frying oil. Differences in the content of other tocols were encountered between chickens and rabbits, which might be attributable to the different tocol composition of their feeds, as well as to species differences in the digestion and metabolism of tocols. Tissue oxidation and susceptibility to oxidation were in general low and were not greatly affected by the degree of oxidation of the oil added to the feeds. The relative content of polyunsaturated fatty acids/αT in these types of samples would explain the differences observed between species in the susceptibility of each tissue to oxidation. According to our results, oils recovered from the frying industry could be useful for feed uses.

Classification of fats and oils involves the recognition of one/several markers typical of the product. The ideal marker(s) should be specific to the fat or oil. Not many chemical markers fulfill these criteria. Authenticity assessment is a difficult task, which in most cases requires the measurement of several markers and must take into account natural and technology-induced variation. The present study focuses on the identity prediction of three by-products of the fat industry (animal fats, fish oils, recycled cooking oils), which may be used for animal feeding. Their identities were predicted by their triacylglycerol fingerprints, their fatty acid fingerprints and their profiles of volatile organic compounds. Partial least square discriminant analysis allowed samples to be assigned successfully into their identity classes. Most successful were triacylglycerol and fatty acid fingerprints (both 96% correct classification). Proton transfer reaction mass spectra of the volatile compounds predicted the identity of the fats in 92% of the samples correctly.

Chicken is the most widely consumed meat all over the world due to chickens being easy to rear, their fast growth rate and the meat having good nutritional characteristics. The main objective of this paper was to study the effects of dietary fatty by-products in low, medium and high levels of oxidized lipids and trans fatty acids (TFAs) on the contents of cholesterol and oxycholesterols in meat, liver, and plasma of chickens. A palm fatty acid distillate, before and after hydrogenation, and a sunflower-olive oil blend (70/30, v/v) before and after use in a commercial frying process were used in feeding trials after adding 6% of the fats to the feeds. Highly oxidized lipid and TFA feeds significantly increased the contents of cholesterol and oxycholesterols in all tissues of chicken (0.01 < p ≤ 0.05). The contents of oxycholesterols in chicken meat, liver and plasma obtained from TFA feeding trials varied between 17 and 48 μg/100 g in meat, 19-42 μg/100 g in liver and 105-126 μg/dL in plasma. In contrast, in the oxidized lipid feeding trials, oxycholesterols varied between 13 and 75 μg/100 g in meat, 30-58 μg/100 g in liver and 66-209 μg/dL in plasma. Meat from chickens fed with feeds containing high levels of TFAs or oxidized lipids may contribute to higher ingestion of cholesterol and oxycholesterols by humans.

Accurate determination of feeding habits using only conventional dietary analysis is usually difficult, due to both biases caused by prey digestibility differences and to the discrete aspect of the sampling. However, combining conventional methods with stable isotope analysis provides an integrated view of the assimilated diet. Here, we measured stable isotope ratios of carbon (delta(13)C), nitrogen (delta(15)N) and sulphur (delta(34)S) in feathers of yellow-legged gull Larus michahellis nestlings from 4 colonies along the western Mediterranean coast, where the gulls consume different proportions of marine, terrestrial and garbage resources. We collected and analysed chicks' regurgitates in each colony, thereby determining the isotopic signatures in a significant sample of prey. By applying a mixing model to our isotopic values, we compared the information provided by the 2 methodologies. According to direct prey sampling and the particular conditions of the breeding areas, populations with more enriched PS values consumed a diet richer in marine prey, with lower delta(15)N signatures indicating garbage consumption. The main pattern resulting from the mixing model agreed with direct diet sampling. However, estimated proportions for small-sized prey were controversial, which indicates that small, soft prey items might be underestimated by regurgitate analysis. We conclude that stable isotope signatures and the use of mixing models are useful tools for the rapid assessment of feeding ecology in certain populations. Solving analytical biases should be considered in future feeding studies, thereby saving time and minimising bird disturbance by using an isotopic methodology

The administration of diets with different protein/energy ratios induce variable but distinctive responses in rats; an excessive protein content tends to decrease fat accumulation, but reversion of this ratio tends to increase adipose tissue mass. The fate of N derived from amino acid metabolism is not only dependent on energy and dietary protein; the increased excretion of urea elicited by high-protein diets contrasts with the lower urea excretion (despite excess dietary protein and energy) in rats fed a cafeteria diet. After one month of exposure to high-protein (HPD) or cafeteria (CD) diets, we administered a gavage of 15N-arginine to undisturbed adult male rats, in order to trace the utilization of this not-recyclable-N amino acid under diets with different protein/energy relationships. Rats fed a high-protein diet excreted higher amounts of N in urine and showed much lower gastrointestinal content of the label. The CD rats decreased the excretion of urine N. Both groups' N balance showed a significant proportion of N not-accounted-for (but excreted nevertheless), the proportion being especially large in the HPD group. In conclusion, the process of disposal of amino acid N through the so far unknown pathway for “non-accounted-for N” is, thus essentially dependent on excess amino acid availability; independently of urea cycle operation and diet energy content.

CONCENTRACIÓN DE ISÓTOPOS ESTABLES DE C Y N EN VARIOS TEJIDOS DE LA TORTUGA BOBA CARETTA CARETTA DEL MEDITERRÁNEO OCCIDENTAL E IMPLICACIONES SOBRE LA DIETA. – La concentración isotópica de escudos del caparazón, piel, músculo y sangre de tortuga boba (Caretta caretta) fueron analizados para investigar el patrón de variación entre tejidos y para evaluar la posición de esta especie en las redes tróficas de la cuenca Argelina. La piel presentaba valores más altos de δ13C que el músculo o los escudos del caparazón y éstos presentaban valores más altos que la sangre. En cambio, el músculo presentaba valores más altos de δ15N que la piel, ésta valores más altos que la sangre y ésta valores más altos que los escudos del caparazón. Las tortugas muertas y las vivas del mismo hábitat no diferían en la concentración de isótopos estables. Sin embargo, alguno de los tejidos de las tortugas capturadas mediante palangre de superficie en el medio oceánico presentaban valores más altos de δ13C que los de las tortugas capturadas a mano o mediante trasmallo en la plataforma continental, aunque no diferían en el δ15N. La comparación de la concentración de isótopos estables de tortuga con la de otras especies de varias áreas de la cuenca Argelina reveló que consumían presas planctónicas y que el nivel trófico de las tortugas era superior que el de los cnidarios carnívoros pero inferior que el de peces y crustáceos zooplanctófagos. The isotopic concentrations of carapace scutes, skin, muscle and blood of loggerhead sea turtles (Caretta caretta) from the Balearic Archipelago were analysed to investigate the pattern of variation between tissues and to assess the position of this species in the trophic webs of the Algerian Basin. Skin showed higher d13C values than muscle or carapace scutes and these showed higher values than blood. Conversely, muscle showed higher d15N values than skin, skin showed higher values than blood and blood showed higher values than carapace scutes. Dead and live sea turtles from the same habitat did not differ in the concentration of stable isotopes. However, some of the tissues of the turtles caught in drifting long-lines in the oceanic realm showed higher d13C values than those from the turtles caught by hand or in trammel nets over the continental shelf, although they did not differ in the d15N. Comparison of the concentration of stable isotopes in the turtles with that of other species from several areas of the Algerian Basin revealed that they consumed planktonic prey and that the trophic level of the sea turtles was higher than that of carnivorous cnidarians but lower than that of zooplanktophagous fish and crustaceans. Manuel.Sanfelix@uv.es

Leishmaniasis is a vector-borne disease transmitted by phlebotomine sand flies. Information about blood meal preferences in sand flies is essential to understand the epidemiology of the disease to adopt control measures. In previous studies, a polymerase chain reaction (PCR) of 359bp fragment of the conserved gene cytochrome b (cyt b) and further sequencing were applied in the study of blood meal sources in sand flies collected in the area of a leishmaniasis outbreak in southwest Madrid, Spain, providing significant information about blood meal preferences in the focus. In this work, a PCR-restriction fragment length polymorphism (RFLP) targeting a fragment of 359bp of vertebrate cyt b gene was developed. Restriction endonucleases HaeIII and HinfI generated specific patterns consistent with the blood meal sources found in sand flies. The protocol has been validated with twenty six engorged females collected in the field with CDC traps. Blood meals from nine vertebrates were identified based on PCR-cyt b and sequencing-human, dog, cat, horse, hare, rabbit, sheep, goat and chicken - and mixed blood meals (sheep/human; sheep/goat) - and successfully distinguished by PCR-RFLP. Therefore, this approach is an efficient and reliable alternative method to be applied in entomological surveys.