Enteric methane emissions and nitrogen utilisation efficiency for two genotype of hill hoggets offered fresh, ensiled and pelleted ryegrass

Thirty-six 12-month-old hill hoggets were used in a 2 genotype (18 Scottish Blackface vs. 18 Swaledale×Scottish Blackface)×3 diet (fresh vs. ensiled vs. pelleted ryegrass) factorial design experiment to evaluate the effects of hogget genotype and forage type on enteric methane (CH4) emissions and nitrogen (N) utilisation. The hoggets were offered 3 diets ad libitum with no concentrate supplementation in a single period study with 6 hoggets for each of the 6 genotype×diet combinations (n=6). Fresh ryegrass was harvested daily in the morning. Pelleted ryegrass was sourced from a commercial supplier (Aylescott Driers & Feeds, Burrington, UK) and the ryegrass silage was ensiled with Ecosyl (Lactobacillus plantarum, Volac International Limited, Hertfordshire, UK) as an additive. The hoggets were housed in individual pens for at least 14 d before being transferred to individual respiration chambers for a further 4 d with feed intake, faeces and urine outputs and CH4 emissions measured. There was no significant interaction between genotype and forage type on any parameter evaluated. Sheep offered pelleted grass had greater feed intake (e.g. DM, energy and N) but less energy and nutrient apparent digestibility (e.g. DM, N and neutral detergent fibre (NDF)) than those given fresh grass or grass silage (P<0.001). Feeding pelleted grass, rather than fresh grass or grass silage, reduced enteric CH4 emissions as a proportion of DM intake and gross energy (GE) intake (P<0.01). Sheep offered fresh grass had a significantly lower acid detergent fibre (ADF) apparent digestibility, and CH4 energy output (CH4-E) as a proportion of GE intake than those offered grass silage (P<0.001). There was no significant difference, in CH4 emission rate or N utilisation efficiency when compared between Scottish Blackface and Swaledale × Scottish Blackface. Linear and multiple regression techniques were used to develop relationships between CH4 emissions or N excretion and dietary and animal variables using data from sheep offered fresh ryegrass and grass silage. The equation relating CH4-E (MJ/d) to GE intake (GEI, MJ/d), energy apparent digestibility (DE/GE) and metabolisability (ME/GE) resulted in a high r2 (CH4-E=0.074 GEI+9.2 DE/GE−10.2 ME/GE−0.37, r2=0.93). N intake (NI) was the best predictor for manure N excretion (Manure N=0.66 NI+0.96, r2=0.85). The use of these relationships can potentially improve the precision and decrease the uncertainty in predicting CH4 emissions and N excretion for sheep production systems managed under the current feeding conditions.

Biomass, quality traits and methane production of extensive grassland: biodiversity effects and sensor approaches

Energy policies around the world are mandating for a progressive increase in renewable energy production. Extensive grassland areas with low productivity and land use limitations have become target areas for sustainable energy production to avoid competition with food production on the limited available arable land resources and minimize further conversion of grassland into intensively managed energy cropping systems or abandonment. However, the high spatio-temporal variability in botanical composition and biochemical parameters is detrimental to reliable assessment of biomass yield and quality regarding anaerobic digestion. In an approach to assess the performance for predicting biomass using a multi-sensor combination including NIRS, ultra-sonic distance measurements and LAI-2000, biweekly sensor measurements were taken on a pure stand of reed canary grass (Phalaris aruninacea), a legume grass mixture and a diversity mixture with thirty-six species in an experimental extensive two cut management system. Different combinations of the sensor response values were used in multiple regression analysis to improve biomass predictions compared to exclusive sensors. Wavelength bands for sensor specific NDVI-type vegetation indices were selected from the hyperspectral data and evaluated for the biomass prediction as exclusive indices and in combination with LAI and ultra-sonic distance measurements. Ultrasonic sward height was the best to predict biomass in single sensor approaches (R² 0.73 – 0.76). The addition of LAI-2000 improved the prediction performance by up to 30% while NIRS barely improved the prediction performance. In an approach to evaluate broad based prediction of biochemical parameters relevant for anaerobic digestion using hyperspectral NIRS, spectroscopic measurements were taken on biomass from the Jena-Experiment plots in 2008 and 2009. Measurements were conducted on different conditions of the biomass including standing sward, hay and silage and different spectroscopic devices to simulate different preparation and measurement conditions along the process chain for biogas production. Best prediction results were acquired for all constituents at laboratory measurement conditions with dried and ground samples on a bench-top NIRS system (RPD > 3) with a coefficient of determination R2 < 0.9. The same biomass was further used in batch fermentation to analyse the impact of species richness and functional group composition on methane yields using whole crop digestion and pressfluid derived by the Integrated generation of solid Fuel and Biogas from Biomass (IFBB) procedure. Although species richness and functional group composition were largely insignificant, the presence of grasses and legumes in the mixtures were most determining factors influencing methane yields in whole crop digestion. High lignocellulose content and a high C/N ratio in grasses may have reduced the digestibility in the first cut material, excess nitrogen may have inhibited methane production in second cut legumes, while batch experiments proved superior specific methane yields of IFBB press fluids and showed that detrimental effects of the parent material were reduced by the technical treatment

Euphorbia tirucalli L.–Comprehensive Characterization of a Drought Tolerant Plant with a Potential as Biofuel Source

Of late, decrease in mineral oil supplies has stimulated research on use of biomass as an alternative energy source. Climate change has brought problems such as increased drought and erratic rains. This, together with a rise in land degeneration problems with concomitant loss in soil fertility has inspired the scientific world to look for alternative bio-energy species. Euphorbia tirucalli L., a tree with C3/CAM metabolism in leaves/stem, can be cultivated on marginal, arid land and could be a good alternative source of biofuel. We analyzed a broad variety of E. tirucalli plants collected from different countries for their genetic diversity using AFLP. Physiological responses to induced drought stress were determined in a number of genotypes by monitoring growth parameters and influence on photosynthesis. For future breeding of economically interesting genotypes, rubber content and biogas production were quantified. Cluster analysis shows that the studied genotypes are divided into two groups, African and mostly non-African genotypes. Different genotypes respond significantly different to various levels of water. Malate measurement indicates that there is induction of CAM in leaves following drought stress. Rubber content varies strongly between genotypes. An investigation of the biogas production capacities of six E. tirucalli genotypes reveals biogas yields higher than from rapeseed but lower than maize silage.

Silagem do bagaço de sorgo sacarino

Brazilian sweet sorghum is used to generate ethanol and the bagasse is burned in industrial boilers or deposited on soil polluting the environment. This study evaluated the performance of sorghum plants and its bagasse silage nutritional value aiming to use it in the ruminant nutrition. Experiments were set up on the UTFPR campus at Dois Vizinhos-PR. The first trial was established on October 2nd, 2012 using the genotypes ADV 2010, Hunnigreen, Sugargraze, Volumax, BR 505, 503, 501 and the second trial at 2013 on November 27th assessing the materials ADV 2010, Sugargraze, Hunnigreen, EX 5110, BR 506, 508, 509 and 511. Experimental was laid out as a randomized block design with three replications. Results were analyzed through ANOVA comparing the averages by Duncan test at 5% error probability. As field variables were evaluated: plant height (Pl hei), green mass production (GM Prod), percentage of leaves, stems and panicles in relation to the plant, stems production without straw (Prod stems with straw), whole stems production (Who stems Prod), stem diameter (Stem diam), juice production (Juice prod) and Brix degree (oBrix). After juice plant extraction, forage bagasse was crushed and packed in silos for 60 days and green matter yield was estimated (GM). In bagasse silage gauged to buffer capacity (BC), dry matter (DM), mineral matter (MM), crude protein (CP), ether extract (EE), total carbohydrates (TC), non-fibrous carbohydrates (NFCH), neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin (LIG ) and digestibility "in vitro" (DIGIV). There was no significant difference (P> 0.05) between genotypes regarding to green matter production and on average, the second crop yield was lower and reflected in the reduction of bagasse production. Bagasse silage DM was of 32.3% and 33.1%; NDF 73% and 65.8%, crude protein 3.8% and 5.9; pH 3.7 and 3.7; TC and 9.8 and 10.7. mg MS-1; the amount of NFCH was 11.1 and 13.5%; DIG of DM 36.9 and 62.4% for the respectively to the bagasse produced from materials grown in the 2012/2013 and 2013/2014 seasons. Hybrid genotypes had a better agronomic performance while the varieties were more efficient in bromatological indexes. And despite the high percentage of NDF and the low protein level, it is possible to feed ruminants with this coproduct.

Wspomagana fitoekstrakcja metali śladowych: Cu, Cd, Zn, Pb

Wydział Biologii

Estudo cinético do branqueamento do óleo da carpa (Cyprinus carpio L)

O óleo de pescado é caracterizado por ser uma fonte rica de ácidos graxos poliinsaturados ω-3, desde modo a sua oxidação lipídica se torna mais favorável quando comparado com outros óleos de origem vegetal. O objetivo do presente trabalho foi a otimização da etapa de branqueamento através da metodologia de superfície de resposta, sendo utilizado misturas de carvão ativado e terra ativada (Tonsil) para a remoção da cor e dos produtos de oxidação, procurando-se preservar o conteúdo total de carotenóides no óleo de carpa. O óleo bruto de carpa (Cyprinus carpio L.) para a realização do trabalho foi obtido a partir da realização de ensilagem ácida, passando posteriormente pelas etapas de refino: degomagem, neutralização, lavagem, secagem e branqueamento. A otimização da etapa de branqueamento foi realizada através de um planejamento fatorial composto central, com os fatores de estudo: a quantidade de adsorvente (Ads) e a quantidade de carvão ativado (Ca), sendo consideradas como respostas o conteúdo total de carotenóides e o valor de TBA. Na melhor condição do branqueamento do óleo de carpa foi realizado um estudo cinético, e para o cálculo das constantes cinéticas foram utilizados os modelos de Brimberg modificado e de Langmuir-Hinshelwood, A condição ótima do branqueamento foi com 2% de adsorvente e 10% de carvão ativado, onde ocorreram menores perdas de carotenóides (44,40%), com redução da cor escura presente no óleo de (85,62%) e redução do valor de TBA (73,10%), obtendo-se um óleo branqueado de carpa com qualidade oxidativa e melhor aspecto em relação à cor. Os dois modelos cinéticos representaram de forma satisfatória os dados experimentais do branqueamento do óleo de carpa, pelos altos coeficientes de determinação e baixos erros médios relativos apresentados. Foi possível observar que ocorreu uma rápida adsorção dos pigmentos carotenóides, e após 30 min a adsorção foi menos eficiente. Nos óleos bruto e branqueado de vísceras de carpa não foi identificada diferença significativa entre as concentrações de ácidos graxos, demonstrando que as etapas de refino utilizadas não alteraram o perfil de ácidos graxos do óleo bruto.

Nutrición animal en sistemas tropicales: uso de residuos agrícolas en la producción animal

El aumento mundial en la demanda de alimentos, especialmente proteína, plantea la necesidad de aplicar estrategias más eficientes y sostenibles de alimentación animal. La capacidad de los rumiantes de utilizar eficientemente la fibra hace posible aprovechar subproductos y residuos agrícolas provenientes de cultivos tropicales como la palma aceitera, banano y mango, los cuales también aportan energía y proteína. Al respecto, Cuenca et al. (2015) mencionan que la harina de almendra de palma posee un valor aproximado de 14.8% de proteína cruda y 8.9% de grasa. Por su parte, Silva et al. (2014) reportan que el uso de harina integral de mango reduce las emisiones de gas y aumenta el contenido de grasa en la leche de cabras Saanen, aunque concentraciones crecientes disminuyen linealmente el volumen de producción. En cuanto a la digestibilidad de estos productos, DiLorenzo et al. (datos no publicados) mencionan que la cascara y fruto maduro del banano presentan una alta digestibilidad in vitro de la materia orgánica (90.45%), superior a la de otros productos del banano, kikuyo y palmiste. Un alimento menos tradicional, el ensilado de pez diablo (EPD) fue incluido en diferentes niveles por Tejeda-Arroyo et al. (2015), en dietas de corderos en crecimiento, obteniendo ganancias de peso de 211.5 g/día (18% EPD) y conversión alimenticia de 6.6 y 6.4 kilogramo de alimento por kilogramo de ganancia de peso (27% EPD y 9% EPD). Se requiere avanzar en la investigación del potencial nutritivo de estos y otros alimentos no tradicionales, así como de las técnicas adecuadas para su mejor utilización, almacenamiento y transporte. El uso de estos subproductos podría reducir los costos de producción y contribuir a disminuir el impacto ambiental de las actividades agrícolas y ganaderas.

Impacto de los forrajes conservados sobre los sistemas de cria vacuna

En los sistemas ganaderos pastoriles, el manejo de excedentes y déficits estacionales e interanuales de forraje mediante el uso de reservas forrajeras impacta sobre la eficiencia de utilización las pasturas (manejo, productividad, y cosecha), y consecuentemente sobre el desempeño animal y productividad del sistema. En este trabajo se reporta información sobre la productividad y calidad de distintos recursos forrajeros que se utilizan para la confección de forrajes conservados. Se presenta información sobre la respuesta animal esperada para distintos momentos de confección, tipos de reservas (henos vs. Silos) para distintas categorías de animales. Se hace particular énfasis en los puntos críticos para lograr reservas de buena calidad y sobre el uso de las reservas como suplemento de pasturas, en dietas de recría y dietas engorde a corral. Finalmente se destacan algunas deficiencias nutricionales comunes en las reservas forrajeras y su modo de corrección. Aunque es bien conocido que la confección de reservas forrajeras - silos y henos - es una herramienta para la intensificación de los sistemas ganaderos que impacta sobre la productividad individual y por hectárea del sistema, hay que tener en cuenta aspectos claves para la obtención de una reserva de buena calidad y optimizar la ventajas de las reservas en el sistema como son la productividad del material a utilizar, el momento de corte, la conservación y la utilización.

Combinación de diferentes estrategias de aplicación de hongos entomopatógenos para el control de Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) y Bemisia tabaci (Gennadius) (Hemiptera:Aleyrodidae)

Los ascomicetos mitospóricos entomopatógenos, que actúan por vía tegumentaria, han sido utilizados para el control microbiano de plagas mediante distintas estrategias que permiten el contacto de sus conidios con los insectos diana. Sin embargo, se conocen nuevos aspectos sobre su función ecológica tales como su capacidad secretora de compuestos con actividad insecticida, así como su sorprendente comportamiento como endófitos, que complementan su empleo clásico y que pueden pantag ermitir el desarrollo de nuevas estrategias de control de plagas. El empleo conjunto de estos hongos y sus extractos para el control de un insecto polífago de importancia mundial Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) es abordado en el capítulo II, donde se pone de manifiesto la existencia de variación intra- e interespecífica en la virulencia y estrategias patogénicas de las cepas de Beauveria bassiana y Metarhizium brunneum evaluadas frente a larvas del noctuido. La aplicación conjunta de cepas con distintas estrategias patogénicas junto con sus extractos a larvas del lepidóptero tuvo efecto aditivo, y alguno antagónico, de lo que depende su empleo conjunto. Los capítulos III y IV revelan la existencia de colonización endofítica transitoria tras la aplicación foliar de suspensiones de conidios de cepas de las especies mencionadas en alfalfa, tomate y melón, así como el impacto de esta colonización sobre dos fitófagos con diferentes hábitos de alimentación, uno masticador S. littoralis y otro picador-suctor Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). El capítulo III muestra la contribución aditiva de la mortalidad causada por la alimentación de larvas de S. littoralis a expensas de material vegetal colonizado endofíticamente por cepas de B. bassiana y M. anisopliae con la debida al tratamiento tópico de las mismas con las suspensiones fúngicas. El origen de la mortalidad iniciada a través de la vía digestiva en larvas de este lepidóptero permanece incierto para las cepas de B. bassiana, pero podría estar asociado a la presencia en la planta de metabolitos fúngicos en las cepas de M. brunneum como denota la presencia de destruxina (dtx) A en el 11,0% de los cadáveres. El capítulo IV revela que cepas de ambas especies fúngicas pueden iniciar ciclos de infección en insectos picadores-suctores cuando se alimentan a expensas de sustrato vegetal colonizado endofíticamente, si bien, ambas especies presentan estrategias diferentes. Así, B. bassiana muestra una gran capacidad para colonizar el melón, incluso con efecto traslaminar, que causa la infección de ninfas de B. tabaci por contacto con el tegumento. Sin embargo, la mortalidad de las mismas causada por M. brunneum, de crecimiento mucho más localizado en la hoja, está relacionada una vez mas con la presencia de dtx A en el 43,0% de los cadáveres. Estos resultados deben ser considerados para la evaluación del impacto real de los tratamientos con hongos entomopatógenos, y abren nuevas vías en el control de plagas.

Desempenho de novilhos suplementados no periodo seco com mistura multipla a base de leucena no semi-arido brasileiro.

O estudo objetivou avaliar uma mistura multipla composta de feno de folhas de leucena (Leucaena leucocephala (Lam.) de Wit.), raspa de mandioca e uma mistura mineral, como suplemento para novilhos azebuados, no periodo seco. A mistura foi comparada com duas outras alternativas de suplementacao: a mistura sal-ureia e a silagem de leucena. Os animais dos tres grupos pastejaram, conjuntamente, em capim buffel (Cenchrus ciliaris, L.). Ao final dos 84 dias do periodo experimental, o incremento em peso vivo nos animais submetidos a mistura multipla (22,1 kg/cab) nao diferiu (P>0,05) do observado nos animais suplementados com silagem de leucena (17,7 kg/cab), mas correspondeu (P<0,05) a quase cinco vezes o observado nos animais submetidos a mistura sal-ureia (4,6 kg/cab).

Evaluación de pollos camperos en producción intensiva y semi-intensiva con suplementación de extracto de quillaja y residuos de hortalizas

En la presente investigación se evaluó: la ganancia diaria de peso, consumo semanal, índice de productividad, mortalidad, conversión alimenticia, costo por kg de carne, pigmentación en tarsos, porcentaje de grasa y el efecto del extracto de quillaja como coccidiostato, bajo dos sistemas de crianza, intensiva y semi-intensiva. El extracto de quillaja fue utilizado al 0,1% de inclusión en el alimento. La investigación se llevó a cabo en la provincia del Azuay, cantón Cuenca, parroquia San Joaquín, sector Balzay Bajo. Se utilizaron 300 pollitos camperos de la estirpe Hubbard variedad redbro S de 1 día de edad. Las aves se distribuyeron de forma aleatoria en un diseño de bloques al azar con 3 tratamientos, cada uno con 5 repeticiones y con 20 pollitos por unidad experimental. Los tratamientos fueron: T1: testigo, aves alojadas en sistema intensivo; T2: aves alojadas en sistema intensivo, más una dieta modificada que consistía en la adición de extracto de quillaja al 0,1%; T3: sistema semi-intensivo con la misma dieta del T2, las aves de este tratamiento a partir del día 28 de edad tuvieron acceso a un área verde delimitada, la cual poseía una mezcla forrajera de raigrás-alfalfa y además se adicionaron a su alimentación residuos de hortalizas propias de la zona. La investigación duró 56 días, no se evidenciaron diferencias significativas en ganancia diaria de peso, índice de productividad, índice de conversión, costo por kg de carne y porcentaje de grasa (p>0,05), mientras que consumo semanal y mortalidad, mostraron diferencias significativas (p<0,05). En las demás variables se evidenció mejor intensidad de pigmentación en T3 (p<0,05), mientras que en la infestación por coccidios no se observó diferencia entre tratamientos (p>0,05), lo que indica que la aplicación de extracto de quillaja tuvo un efecto similar al programa anticoccidial utilizado en T1

Balanço energético da produção de feno da forrageira "massai" para criação de equídeos

Dissertação (mestrado)—Universidade de Brasília, Faculdade de Tecnologia, Departamento de Engenharia Mecânica, 2016.

Avaliação microbiológica e bromatológica da silagem ácida obtida de resíduos da indústria de filetagem de tilápia do Nilo (Oreochromis niloticus)

The experiment constituted in evaluating the acid silage prepared from Nile tilapia (Oreochromis niloticus) filletage industry residues. This silage was prepared in a filetage industry through the residues milling and 5% of ascetic acid addition and stock piling in a period up to until 201 days. Storaged silages in a period of 7, 12, 22, 27, 41, 48, 61, 75, 84, 91, 96, 110, 140, 151, 181, 187 and 201dias were evaluated. Bromatologics analyses of rude protein(PB), etereal extract (EE), humidity (UM), ashes (CZ) and microbiological analyses of Salmonella, total coliforms, faecals and Escherichia coli of the storaged silages in a period of 7, 91 and 201 days were realized. The pH was evaluated in all the storaged periods. Differences (P > 0.05) in the substance of PB, EE, UM and CZ were not observed. A linear increase in PH was observed, being stabilizing in plateau of 4.74. In relation to the microbiological analysis the presence of Salmonella, total coliforms, faecals and E. Coli were not found. Was concluded that the acid silage gotten from tilapia filetage residues produced with the use of 5% ascetic acid can be stored during 201 days without having Salmonella, total coliforms and faecals proliferation.

Potential mitigation of midwest grass-finished beef production emissions with soil carbon sequestration in the United States of America

Beef production can be environmentally detrimental due in large part to associated enteric methane (CH4) production, which contributes to climate change. However, beef production in well-managed grazing systems can aid in soil carbon sequestration (SCS), which is often ignored when assessing beef production impacts on climate change. To estimate the carbon footprint and climate change mitigation potential of upper Midwest grass-finished beef production systems, we conducted a partial life cycle assessment (LCA) comparing two grazing management strategies: 1) a non-irrigated, lightly-stocked (1.0 AU/ha), high-density (100,000 kg LW/ha) system (MOB) and 2) an irrigated, heavily-stocked (2.5 AU/ha), low-density (30,000 kg LW/ha) system (IRG). In each system, April-born steers were weaned in November, winter-backgrounded for 6 months and grazed until their endpoint the following November, with average slaughter age of 19 months and a 295 kg hot carcass weight. As the basis for the LCA, we used two years of data from Lake City Research Center, Lake City, MI. We included greenhouse gas (GHG) emissions associated with enteric CH4, soil N2O and CH4 fluxes, alfalfa and mineral supplementation, and farm energy use. We also generated results from the LCA using the enteric emissions equations of the Intergovernmental Panel on Climate Change (IPCC). We evaluated a range of potential rates of soil carbon (C) loss or gain of up to 3 Mg C ha-1 yr-1. Enteric CH4 had the largest impact on total emissions, but this varied by grazing system. Enteric CH4 composed 62 and 66% of emissions for IRG and MOB, respectively, on a land basis. Both MOB and IRG were net GHG sources when SCS was not considered. Our partial LCA indicated that when SCS potential was included, each grazing strategy could be an overall sink. Sensitivity analyses indicated that soil in the MOB and IRG systems would need to sequester 1 and 2 Mg C ha-1 yr-1 for a net zero GHG footprint, respectively. IPCC model estimates for enteric CH4 were similar to field estimates for the MOB system, but were higher for the IRG system, suggesting that 0.62 Mg C ha-1 yr-1 greater SCS would be needed to offset the animal emissions in this case.

Diet composition of a declining steppe bird the Little Bustard (Tetrax tetrax) in relation to farming practices

Foraging strategies and diet selection play an essential role in individual survival and reproductive success. The study of feeding ecology becomes crucial when it concerns endangered species such as the Little Bustard (Tetrax tetrax), whose populations are suffering strong declines as a consequence of agricultural intensification. Despite the fact that several populations are overwintering in areas affected by agricultural transformation, nothing is known about how feeding behavior responds to these changes. We studied for the first time the winter diet composition of the Little Bustard in Spain and compared it between areas with two different farming systems: dry and irrigated farmland. Diet was studied through the micro-histological analysis of 357 droppings collected in 16 locations across the wintering range of the Little Bustard in Spain. Up to 62 plant species were identified. Most consumed species were cultivated legumes (46.7%) and dicotyledon weeds (45.6%), while monocotyledons were scarcely consumed (7.7%). Diet composition differed significantly between dry and irrigated farmland areas. In irrigated areas, diet was mainly composed of legumes, in particular alfalfa (Medicago sativa). In contrast, in dry farmland areas diet was more diverse, composed mainly of weeds (Compositae, Papaveraceae, and Cruciferae) and also cultivated legumes, particularly vetch (Vicia sativa). These results suggest that legume crops could be an effective measure to improve habitat quality in areas with scarce food resources. However, in the case of irrigated areas, the strong reliance on alfalfa could make the Little Bustard more vulnerable to changes in land use. This study is the first step to understand the winter trophic requirements of the endangered Little Bustard, but further research is necessary to understand the food requirements of this species during the entire annual cycle.