Gustavo Daniel Vega-Britez

Prof. Dr. Gustavo Daniel Vega-Britez

orcid
Universidad Nacional de Asunción. Facultad de Ciencias Agrar...

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 January 2021 in Veterinary World
Verified
Journal Article
Open access
FJFernando Miranda Vargas Junior
Fernando Miranda Vargas Junior
Tatiane FernandesTatiane Fernandes
Tatiane Fernandes
AMAlexsander Toniazzo de Matos
Alexsander Toniazzo de Matos
AFAlexandre Rodrigo Rodrigo Mendes Fernandes
Alexandre Rodrigo Rodrigo Mendes Fernandes
LALuis Gustavo Castro Alves
Luis Gustavo Castro Alves
NZNatássia Gabriela Targanski Zagonel
Natássia Gabriela Targanski Zagonel
Background and Aim: Ultrasound is a non-invasive technique that enables animal evaluation and body condition classification of animals. Although it is not difficult to obtain an image, the analysis of this image can influence results quality. This study aimed to evaluate the repeatability and reproducibility of the technician trained in image interpretation obtained using different ultrasound frequencies. Materials and Methods: Ninety-six lambs were used, ranging in weight from 15 to 40 kg. The images were captured using a linear probe of 13 cm, with a 3.5 megahertz (MHz) frequency and an acoustic couplant aid "standoff" or using a multifrequency transducer (6 and 8 MHz), on B mode, with a linear probe and 8.0 MHz frequency. All measurements were performed by the same technician, on the left side, between the 12th and 13th rib. Five different evaluators, at two different times, with aid of Image J software measured the loin eye area (LEA; only for images obtained with 3.5 MHz), Longissimus thoracis et lumborum depth (DLM), subcutaneous fat thickness (SFT), subcutaneous fat thickness plus skin (SFST), and skin thickness (ST). Results: For LEA, DLM, SFT, SFST, and ST, variation was observed (p0.05) between the 2 times of evaluation. Images measurements obtained with a frequency of 8.0 MHz had better repeatability indices and reproducibility indices. Accordingly, the identity test demonstrated that measurements performed on images obtained using 3.5 or 8.0 MHz were not equivalent. Conclusion: Ultrasound image measurements obtained using an 8.0 MHz frequency were more accurate and precise. It is important to use only one evaluator or providing the simultaneous training for all evaluators.

20 January 2025 in Ruminants
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IOINESSA STEFFANY TORRES OLIVEIRA
INESSA STEFFANY TORRES OLIVEIRA
Tatiane FernandesTatiane Fernandes
Tatiane Fernandes
ASAylpy Renan Dutra Santos
Aylpy Renan Dutra Santos
CACarolina González Aquino
Carolina González Aquino
Gustavo Daniel Vega-BritezGustavo Daniel Vega-Britez
Gustavo Daniel Vega-Britez
FJFernando Miranda Vargas Junior
Fernando Miranda Vargas Junior
This study evaluated the phytochemical composition of aqueous extracts of Moringa oleifera (MO) obtained by maceration, decoction, and infusion of fresh or dried leaves and their effects on in vitro ruminal fermentation parameters. Phytochemical prospecting analyses were conducted to determine the bioactive compounds in each aqueous extract. Regarding the in vitro ruminal fermentation study, the seven treatments were the following: no addition of extract or control (CON); extract obtained by maceration of fresh leaves (MFL); extract obtained by maceration of dry leaves (MDL); extract obtained by decoction of the fresh leaves (DFL); extract obtained by decoction of dry leaves (DDL); extract obtained by infusion of fresh leaves (IFL) and extract obtained by infusion of dry leaves (IDL). The concentration of all bioactives (saponins, flavonoids, tannins, and alkaloids) quantified was higher when fresh MO leaves were used (p < 0.001). DFL and DDL provided less elimination of azino-bis radicals. On the other hand, MFL resulted in a greater elimination of these radicals. Extracts obtained from fresh leaves resulted in a greater total production of short-chain fatty acids, acetate, and butyrate (p < 0.05). Compared to the control treatment, the inclusion of extracts obtained from fresh leaves provided a higher concentration of propionate (p = 0.049). It is thereby concluded that the use of fresh MO leaves for the production of aqueous extracts is the most recommended, as it results in a higher concentration of bioactive compounds. The use of aqueous extracts of fresh MO leaves increases the total production of fatty acids but does not change their proportion.

28 August 2020 in Archives Animal Breeding
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Gustavo Daniel Vega-BritezGustavo Daniel Vega-Britez
Gustavo Daniel Vega-Britez
FJFernando Miranda Vargas Junior
Fernando Miranda Vargas Junior
MRMarciana Retore
Marciana Retore
MSMarcelo Corrêa Silva
Marcelo Corrêa Silva
LLLuana Liz Medina Ledesma
Luana Liz Medina Ledesma
TFTatiane Fernandes
Tatiane Fernandes
The nutritional requirements can be met, and carcass quality can be achieved by using concentrate supplementation in the diets of grazing lambs. This study evaluated the effects of different concentrate supplementation rates (0 %, 1.5 %, and 3 % of body weight) and tropical pastures (Panicum maximum cv. `Aruana' and Brachiaria brizantha cv. `Marandu') on lamb carcass traits. Thirty-six male Suffolk lambs, with an initial body weight of 22.54 ± 2.72 kg, were evaluated in a 3 × 2 factorial experimental design. The concentrate used consisted of milled soybean, maize, and oat grains. The pasture species affected empty body weight and commercial cuts. The use of concentrate supplementation affected carcass weight, yield, indexes, and commercial cuts. Also, the use of concentrate supplementation improved the weight of muscle and fat content. Based on discriminant analysis it is possible to identify the rearing systems, when all variables where used, or the level of concentrate supplementation when variables of weight were used. Carcasses of animals on grass-only diets were different and easier to discriminate. The use of concentrate supplementation on rearing lambs improves the quality of carcass traits. The period of finishing can be shorted with supplementation of 3 % of body weigh in Aruana and Marandu grass. The discriminant analysis can identify the differences between rearing systems based on all carcass traits. This analysis can be used to develop carcass traceability systems.

29 September 2024 in Frontiers in Bioscience-Scholar
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LSLayonel Alves de Sousa
Layonel Alves de Sousa
AAAdriana Araujo
Adriana Araujo
FSFrancisco de Assis Diniz Sobrinho
Francisco de Assis Diniz Sobrinho
MBMiklos Maximiliano Bajay
Miklos Maximiliano Bajay
RJRAQUEL Soares SOARES JULIANO
RAQUEL Soares SOARES JULIANO
FJFernando Miranda Vargas Junior
Fernando Miranda Vargas Junior
Background: Sheep farming is growing substantially in Brazil, driven by the increasing demand for sheep meat. This rising demand has heightened the focus on sheep, making them the subject of numerous studies, including those centered on genetic analysis. A notable research area involves Pantaneiro sheep, which are indigenous to the Pantanal region of Mato Grosso do Sul and other locations. These sheep are of particular interest due to their adaptation to the unique environmental conditions of the Pantanal, a floodplain characterized by its distinctive climatic and ecological features. This study primarily aimed to conduct a comprehensive genomic analysis of Pantanal sheep subjected to natural selection within the Pantanal region and compare different sample herds using methodological approaches. Methods: Genomic analysis was performed to examine genetic diversity and structure via GGP50K single nucleotide polymorphism (SNP) analysis. A sample of 192 adult sheep over 4 years old was categorized into seven populations based on location: Six populations comprised Pantaneiro sheep with one Texel sheep population. Outlier SNPs were assessed to pinpoint regions under natural selection, with comparisons between the Pantaneiro and the commercial Texel breeds. All data analyses were conducted using the R programming language, employing specialized genetic analysis packages. These outlier SNPs were detected using three methodologies, PCAdapt, OutFLANK, and FDIST2/fsthet, with false discovery rate (FDR) corrections applied to ensure result accuracy. Each method was evaluated, and the genes associated with the identified SNPs were cross-referenced with the most recent sheep genome database, focusing specifically on genes with known phenotypic traits. Results: Analysis of a sample comprising 192 adult individuals revealed greater genetic variability within the Pantaneiro breed than the Texel breed, highlighting the adaptation of the Pantaneiro breed to the unique Pantanal environment. Conversely, the Texel breed exhibited significantly higher levels of inbreeding, attributed to its controlled breeding practices. Outlier SNPs were detected with notable variation across different methodologies, underscoring the importance of FDR correction in ensuring the reliability and concentration of identified outliers. These outlier SNPs facilitated the identification of genes associated with key phenotypic traits, including hair growth, tissue regeneration, pigmentation regulation, and muscle capacity. Conclusion: The integrated analysis of methodologies demonstrated significant efficiency in elucidating the genomic landscape of Pantanal sheep, highlighting the genetic richness inherent in sheep from the Pantanal region of Mato Grosso do Sul. The techniques employed effectively identified outlier SNPs associated with phenotypically relevant genes. These findings, which reveal greater genetic variability and adaptability, underscore the potential of these animals for future research and their significance within Brazilian sheep farming. The Texel breed served as a valuable comparative group, illustrating the limited genetic variability in highly controlled breeding environments.

3 June 2020 in Intropica
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MFMarcos Arturo Ferreira-Aguero
Marcos Arturo Ferreira-Aguero
ABArsenio Benítez-Sánchez
Arsenio Benítez-Sánchez
JVJosé Augusto Velásquez
José Augusto Velásquez
Gustavo Daniel Vega-BritezGustavo Daniel Vega-Britez
Gustavo Daniel Vega-Britez
NLNelson David Lesmo-Duarte
Nelson David Lesmo-Duarte
MAMatheus Francisco Acosta-Resquín
Matheus Francisco Acosta-Resquín
El maíz transgénico que expresa la toxina de Bacillus thuringiensis (Bt) produce un cristal (Cry) de proteína tóxica para las orugas de las hojas y los tallos de maíz Bt, pero es atóxica para chinches. Los objetivos de este estudio fueron identificar la cantidad de plantas de maíz atacadas y no por la chinche barriga verde Dichelops melacanthus, evaluar los daños foliares a través del número de punturas, la altura de plantas y la producción en peso de granos de las plantas de maíz atacadas y no. La investigación se realizó en una granja agrícola de producción comercial en una superficie de 700 m2. Los datos fueron registrados en hoja impresa, tabulada en planilla electrónica Excel y analizados estadísticamente por el test T-Student con una significancia del 5 % para comparación de dos grupos de muestras independientes. Los resultados obtenidos indican que el 80,7 % de las plantas de maíz fueron atacadas por la chinche D. melacanthus presentando punturas foliares. La altura promedio de las plantas atacadas fue de 41,2 ± 2,2 cm y 41,5 ± 3,3 cm de las no atacadas. En relación a la producción se ha verificado una reducción significativa del 23 %. El peso de los granos de maíz por planta atacada tuvo un promedio de 3,048 ± 199 g y 3,956 ± 269 g en planta no atacada, demostrando así que los daños ocasionados por D. melacanthus reducen el rendimiento del maíz Bt.

5 February 2024 in Grasses
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Gustavo Daniel Vega-BritezGustavo Daniel Vega-Britez
Gustavo Daniel Vega-Britez
MRMarciana Retore
Marciana Retore
ASAllison Manoel de Sousa
Allison Manoel de Sousa
ASAdrielly Laís Alves Silva
Adrielly Laís Alves Silva
CACarolina Marques Costa Araújo
Carolina Marques Costa Araújo
FJFernando Miranda Vargas Junior
Fernando Miranda Vargas Junior
In Brazil, grazing is the main or only source of food for livestock. The appropriate combination of supplementation with concentrate in a lamb’s diet on pasture is an alternative that can be explored to use natural resources to produce quality meat. The aim of the current study was to evaluate the effects of different supplementation levels (0%, 1.5%, and 3% of BW) on the intake, performance, and production costs of lambs grazing on Aruana (Megathyrsus maximus) and Marandu (Brachiaria brizantha) grasses. Thirty-six non-castrated male Suffolk lambs (22.54 ± 2.72 kg) were used. The lambs were evaluated for nutrient intake and digestibility, such as dry matter (DM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and consumption in relation to body weight (% BW), in addition to the average daily gain (ADG), body condition score (BCS), and hot carcass weight (HCW), as well as the rising production cost of each system. The dry matter of the green leaf blades was influenced by the pasture type (p < 0.05), producing 1503.6 vs. 2977.4 kg/ha of Aruana and Marandu grasses, respectively. The concentrate supplementation level influenced the type of pasture (p < 0.05). A higher consumption of DM, CP, NDF, and organic matter was registered for the supplemented animals (p < 0.05) and on Aruana grass. The intake in relation to body weight was significantly influenced by the concentrate levels (p < 0.05). The empty body weight and HCW were significantly influenced by the supplementation levels (p < 0.05). The ADG and feed conversion (FC; kg DM/ADG) were influenced by the supplementation levels and type of pasture. The BCSs differed between the concentrate levels (p < 0.05). The supplementation improved dry matter digestibility. The ADG and FC were superior in the supplemented animals, with an advantage for those grazing on Aruana grass. The slaughter ADG was also higher in the supplemented animals. The lambs’ pasture comprising Aruana grass with 1.5% BW of concentrate supplementation showed improved production and economic results.