REDI - Digital Repository of the National Agency of Research and Innovation
Not a member yet
4796 research outputs found
Sort by
Identificando las estrategias de invasión de Cynodon dactylon en pastizales. [poster].
No full textCynodon dactylon es la invasora con mayor rango de distribución en Uruguay y su expansión se asocia frecuentemente a disturbios. El objetivo de este trabajo fue evaluar la habilidad competitiva de Cynodon dactylon al interactuar con dos de las principales gramíneas nativas del pastizal natural
Impact of standing water level and observation time on remote-sensed canopy indices for rice nitrogen status monitoring.
No full textABSTRACT.- The observation time and water background can affect the remote sensing estimates of the nitrogen (N) content in rice crops. This makes the use of vegetation indices (VIs) for N status monitoring and topdressing recommendations challenging, as the timing of panicle initiation and the water level in bays usually differ between farms even when managed using the same irrigation technique. This study aimed to investigate the influence of standing water levels (from 0 to 20 cm) and the time of image acquisition on a set of N-sensitive VIs to identify those less affected by these factors. The experiment was conducted using a split-plot experimental design with two side-by-side bays (main plots) where rice was grown ponded for most of the growing season and aerobically (not permanently ponded), each with four fertilization N rates. © 2025 by the authors. Licensee MDPI, Basel, Switzerland
Herbívoros y fuegos: Su rol en la configuración de la estructura y el funcionamiento de los pastizales del Río de la Plata. [Grazers and fires: Their role in shaping the structure and functioning of the Río de la Plata Grasslands.].
No full textABSTRACT.- The Río de la Plata Grasslands (RPG) are one of the largest areas of open ecosystems (grasslands, shrublands and savannas) in the world. Historically, these systems have experienced, and continue to experience, an enormous loss of natural habitats. Moreover, their importance has been largely invisible in comparison to forested systems. The remaining area of open ecosystems in the RPG region varies according to the source from 38 to 58% of the original area. Open Ecosystems (OE) are a special case of agroecosystems because they can combine the supply of both provisioning and regulating and supporting ecosystem services (ES). Preserving the provision of ES in these natural habitats depends, in part, on understanding the role of the two main disturbances operating in them: grazing and fire. Although these two disturbances are natural components of OE, both are manipulated by humans. In this paper we reviewed the role played by fire and grazing in the structure and functioning of the RPG starting from the late Pleistocene and Holocene, and summarizing current evidence on the effects of fire and grazing on vegetation, fauna and biogeochemical processes. The evidence indicates that among agricultural activities, direct grazing systems in OE have the lowest environmental footprint. At the same time are the key for habitat preservation and ES supply. Overall, the OE of the RPG still represent a high proportion of the area, are capable of covering 2.5% of the world?s population needs of high quality protein and, at the same time, guarding the regulation of key processes. .-.-.-.-.-.-.-.-.-.-.-.-.-.-. RESUMEN.- Los Pastizales del Río de la Plata (PRP) son una de las áreas más extensas de ecosistemas abiertos (pastizales, arbustales y sabanas) del mundo. Históricamente, estos sistemas han experimentado, y lo siguen haciendo, una enorme pérdida de hábitats naturales. Más aun, en buena medida, su importancia ha sido invisibilizada frente a sistemas boscosos. El área remanente de ecosistemas abiertos (EA) varía según las fuentes del 38 al 58% del área original. Los EA son agroecosistemas particulares porque pueden combinar el suministro tanto de servicios ecosistémicos (SE) de provisión como de regulación y soporte. La maximización del suministro de SE en estos hábitats naturales depende, en parte, de comprender el papel de las dos principales perturbaciones que operan en ellos: el pastoreo y el fuego. Aunque estas dos perturbaciones son componentes naturales de los EA, son manipuladas por prácticas humanas. En este artículo revisamos el papel del pastoreo y el fuego en la estructura y el funcionamiento del PRP, partiendo de su papel durante el final del Pleistoceno y el Holoceno, y resumiendo evidencias de los efectos actuales del pastoreo y el fuego sobre la vegetación, la fauna y los procesos biogeoquímicos. Las evidencias muestran que los sistemas ganaderos en EA tienen, en dimensiones claves de la huella ambiental tales como la preservación de hábitats y la oferta de SE, el menor impacto entre las actividades agropecuarias. Los valores estimados de producción de carne equivalente en los EA representan una alta proporción de la producción total de la región, un volumen de producción capaz de cubrir el consumo de un 2.5% de la población mundial
Methane emissions and rumen microbiome response during compensatory growth on either a forage or grain-based finishing diet in beef cattle.
No full textABSTRACT.- The aim of this experiment was to evaluate the effect of the level of prior nutritional restriction during backgrounding in Angus steers on methane (CH4) emissions, diet digestibility, rumen fermentation, and ruminal microbiome under either a forage or grain-based finishing diet. © 2024 The Author(s). Published by Oxford University Press on behalf of the American Society of Animal Science
Age at first gestation in beef heifers affects fetal and postnatal growth, glucose metabolism and IGF1 concentration.
No full textThis study aimed to determine the effects of age at first gestation on offspring growth performance, glucose metabolism, and IGF1 concentration. Heifers impregnated by AI from a single bull at 15 months of age (15 M, n = 20), or 27 months of age (27 M, n = 20), and multiparous cows (adult, n = 20) were used. Dams from all groups were managed in a single group during gestation and lactation. Gestational length was longer in the 15 M and 27 M than in adult dams (p = 0.009). Bodyweight at birth, at weaning and ADG during lactation were higher in calves from adult dams than in those from 27 M dams, and higher in calves from the latter than in 15 M calves (p < 0.001). Calves from 15 M dams had an increased head circumference/BW ratio compared to calves from 27 M dams, while calves from this latter group had an increased ratio compared to calves from adults (p = 0.005). Body mass index was greater in calves from adults than in those from 15 M and 27 M dams (p = 0.002). Milk production from 15 M and 27 M dams was similar but lower than that from adults (p = 0.03). Calves born from adult dams had greater blood glucose concentrations than those from 15 M and 27 M dams (p < 0.05). Serum IGF1 concentrations were higher in calves from adults than in calves from 15 M and 27 M dams (p = 0.01). This study showed that age at first gestation affects offspring postnatal growth performance, glucose metabolism and IGF1 concentration
Fotosensibilización hepatógena en bovinos provocada por fasciolasis crónica. [Bovine hepatogenic photosensitization caused by chronic fasciolasis.]
No full textRESUMEN.- La fotosensibilización hepatógena en bovinos puede ser provocada por diversas causas, entre ellas, como consecuencia del daño que provoca Fasciola hepatica a nivel hepatocelular. La fotodermatitis de origen hepatógeno es uno de los signos clínicos que se puede observar en cuadros de fasciolasis crónica, debido en su capacidad de producir fibrosis hepática y colangitis con estasis biliar. El objetivo de este trabajo fue describir dos brotes de fotosensibilización hepatógena en bovinos en los departamentos de Tacuarembó y Soriano (Uruguay). La enfermedadafectó a un lote de vacas Hereford y cruza, y a un lote de vaquillonas cruzas. En ambos brotes los animales pastoreaban en campos forestales húmedos. Los principales signos clínicos observados fueron pérdida de peso, costras y peladuras en morro, fotofobia, sialorrea y corrimientos oculares. Se realizaron necropsias visualizando como hallazgos macroscópicos relevantes dermatitis necrótica bilateral de los párpados, úlceras en cara ventral de lengua. En hígado se observó engrosamiento de la cápsula de Glisson, fibrosis difusa y colangitis crónica con calcificación de los canalículos biliares. Al examen histopatológico se destacó como principal lesión, fibrosis hepática y obstrucción canalicular con presencia de Fasciola hepatica. En base a los signos clínicos, hallazgos macro y microscópicos, la fotosensibilización observada en los animales de ambos brotes estuvodirectamente relacionada con las alteraciones hepáticas crónicas causadas por F. hepatica. ----------------- SUMMARY.- Bovine hepatogenic photosensitization can be caused by several causes, such as hepatocellular damage due to by Fasciola hepatica. Hepatogenic photodermatitis is one of the clinical signs that can be observed in chronic fasciolasis, caused by hepatic fibrosis and cholangitis with bile stasis. The objective of thiswork was to describe two outbreaks of hepathogenic photosensitization in cattle in the counties of Tacuarembó and Soriano (Uruguay). The disease affected a herd of Hereford and crossbreed cows and a herd of crossbreed heifers. In both outbreaks the animals grazed in damp forest fields. The main clinical signs observed were weight loss, scabs and peeling on the snout, photophobia, hypersalivation and ocular bleeding. In all necropsiesperformed, the relevant macroscopic findings were bilateral necrotic dermatitis of the eyelids, ulcers on the ventral surface of the tongue. In the liver, there was thickening of the Glisson's capsule, diffuse fibrosis, and chronic cholangitis with calcification of the bile canaliculi. Histopathologically the main lesion was liver fibrosis and canalicular obstruction with the presence of F. hepatica. Based on the clinical signs, macro and microscopicfindings, the photosensitization observed in the animals of both outbreaks was directly related to the chronic liver alterations caused by F. hepatica
Plant phenotyping and root-associated metabolomics reveal insights into pathogen protection by diverse arbuscular mycorrhizal fungi.
No full textABSTRACT.- Societal Impact Statement: Arbuscular mycorrhizal (AM) fungi support plant development by enhancing growth and resistance to pathogens through mycorrhiza-induced resistance (MIR). However, the varying capacities of individual AM fungal species to induce MIR are not well-understood, limiting their agricultural potential. This study reveals that specific AM fungal isolates differ in their ability to enhance tomato growth and reduce biomass losses due to Rhizoctonia solani infection, a major root pathogen. By identifying MIR-effective fungal isolates and linking them to shifts in root-associated chemical composition, we highlight potential to improve crop resilience and productivity, advancing agriculture by enabling more efficient use of AM fungi.© 2025 The Author(s). Plants, People, Planet published by John Wiley & Sons Ltd on behalf of New Phytologist Foundation
Diagnóstico, manejo y control de enfermedades en soja: 15 años de investigación en Uruguay.
No full textEl vertiginoso crecimiento observado en el área de cultivo de soja [Glycine max (L.) Merr.] desde el año 2000 a la fecha, hizo que este cultivo pasara de ser prácticamente inexistente a transformarse en el principal cultivo de secano en el país. ---- CONTENIDO: 1.- Introducción. -- 2.- Patógenos de semilla. -- 3.- Patógenos de suelo. -- 4.- Relevamiento y cuantificación de enfermedades en planta adulta. -- 5.- Enfermedades foliares. -- 6.- Enfermedades de tallo en soja. -- 7.- Enfermedades de raíz en soja. -- 8.- Agradecimientos. -- 9.- Bibliografía
Diagnóstico molecular de Neospora caninum en fetos abortados espontáneamente en bovinos de Uruguay. [Molecular diagnosis of Neospora caninum in aborted bovine fetus from Uruguay.].
No full textRESUMEN - En Uruguay el diagnóstico de rutina de Neospora caninum se realiza fundamentalmente por estudios histopatológicos de los fetos abortados complementando esta información con resultados deserología y/o Inmunohistoquímica (IHQ). El objetivo de este estudio fue estandarizar un protocolo de amplificación de secuencias mediante PCR (polymerase chain reaction) para la detección de Neospora caninum en órganos de fetos abortados espontáneamente en bovinos para su incorporación a la rutina diagnostica. Para dicho propósito se realizó un estudio retrospectivo utilizando muestras congeladas de archivo de un periodo comprendido entre el año 2013 y 2016, con diagnostico positivo o negativo a Neospora caninum. Los resultados mostraron que de 31 muestras positivas a Neospora caninum por las técnicas de rutina, 26 fueron positivas por PCR (84%), demostrando una alta sensibilidad de diagnóstico de la técnica. Todas las muestras con diagnostico negativo mediante histopatología (n=20) fueron confirmadas como negativo mediante PCR. La comparación de los resultados de PCR con los de histopatología, mediante el test de Cohen?s Kappa, indicó un acuerdo muy alto (81%, p<0.001) entre ambos diagnósticos. Dichos resultados sumados a la simplicidad y rapidez de la PCR podrían sugerir a la PCR como alternativo de la IHQ como técnica confirmatoria en el diagnóstico de rutina. También permite realizar análisis retrospectivos de muestras archivadas, paso fundamental para futuros estudios genéticos de la población de N. caninum presente en Uruguay.-.-.-.-.-.-.-.-.-.-.-.-.-.-.ABSTRACT - The diagnosis of Neospora caninum in Uruguay is carried out by histopathological studies of aborted fetuses, complementing this information with serology test and/or immunohistochemistry (IHC) results. The aim of this study was to standardize a protocol of polymerase chain reaction (PCR) to detect of N. caninum in organs of spontaneously aborted bovine fetus. A retrospective study was conducted using frozen samples from a period between 2013 and 2016, with positive or negative diagnosis of N. caninum. Results showed that 26 of 31 samples positives for N. caninum by routine techniques were positive by PCR, demonstrating a high sensitivity of the PCR. All negative samples by Histopathology (n=20) were confirmed as negative by PCR. Cohen?s Kappa test indicated a very high agreement (81%, p<0.001) between PCR and Histopathology with serology test and/or immunohistochemistry (IHC) results. The high sensitivity, specificity and simplicity of PCR test suggest this technique as an alternative to IHC as a confirmatory technique in routine diagnosis
Residual feed intake for Australian Merino sheep estimated in less than 42 days of trial.
No full textABSTRACT.- The evaluation of sheep feed intake (FI) in feed efficiency tests is expensive. Decreasing the test period could be a resource-saving tool by reducing the cost of evaluating each animal and allowing to test a greater number of animals per year. For this reason, the objective of this research was to explore residual feed intake (RFI) models and to decreasing the test duration. Data was collected from 286 Australian Merino sheep of three performed trials, the test period consisted of 56 days (14 days of feed and facilities adaptation and 42 days of FI and average daily gain (ADG) evaluation). Two models were used to calculate RFI, Model 1 (based on Koch et al. (1963) linear model) and Model 2 (repeated measures, weekly model). Model 1 included ADG and FI estimates in a linear regression. The second model included weekly average FI as repeated measure and the weekly ADG. The increase in body weight during the test period was not perfectly linear, presenting a marked variance increase in two of the three tests while FI presented a tendency to increase throughout of the evaluation period, however presenting a high variance per day. In the 42-days tests, Pearson and Spearman correlations between models for ADG were of 0.89 and 0.87, respectively. The best correlations were detected for FI between 42 and 35-days models, presenting Pearson and Spearman correlations of 0.95 and 0.94 in the linear model, and 0.96 and 0.95 in the weekly model. When considering RFI, the correlations between linear and weekly 42-days models were from 0.93 to 0.92, respectively. The 35-days RFI length models (linear and weekly) presented a Pearson and Spearman correlations greater than 0.98 with the 42-days models. Therefore, the RFI models 35-days of duration allowed to decrease seven days of the FI test while maintaining accuracy and explaining 75.3% of the FI in the linear model, and 63.6% of the weekly model. Reducing seven days of testing would provide a greater data collection into a year of phenotypic evaluation. © 2022 The Authors. Published by Elsevier B.V