Arnulfo Rigoberto Portilla

Mr. Arnulfo Rigoberto Portilla


Research Focus & Metrics

Academic Career Length

4Years (2023-Present)

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

Representative Publications

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6 January 2025 in Siembra
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Journal Article
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JOJorge Eduardo Grijalva Olmedo
Jorge Eduardo Grijalva Olmedo
PMPaola Mercedes Palate Moreta
Paola Mercedes Palate Moreta
RVRoy Vera-Velez
Roy Vera-Velez
RVRaul Armando Ramos Veintimilla
Raul Armando Ramos Veintimilla
JTJean-François Tourrand
Jean-François Tourrand
APArnulfo Rigoberto Portilla
Arnulfo Rigoberto Portilla
In the Andean hillsides of Ecuador, indigenous populations use land mainly for grazing sheep and cattle. Animal response depends exclusively on the quality of forage and the soil’s physical and chemical conditions. The objective of this research was to evaluate two scenarios for intensifying pastures based on perennial ryegrass (Lolium perenne) and white clover (Trifolium repens), used at rest periods of 45- and 60 days in sites between 3,000-3,400 m a.s.l. used for grazing sheep and cows. These scenarios were compared with a natural grassland based on a plant community composed of Stipa ichu, Holcus lanatus, Rumex acetocella, and Paspalum sp., used in a traditional system with rest periods of 60-75 days in sites between 3,500-3,700 m a.s.l. in the Chimborazo River micro-watershed. Soil sampling was conducted at both sites to determine the soil fertility profile. Regarding the forage component, chemical composition, animal carrying capacity, milk production, and estimated enteric CH4 emissions were determined. In sheep serum, Ca, P, and Mg profiles, and the activity of AST, ALT, and FA enzymes were analyzed. The data were analyzed using ANOVA and Tukey 5% as a means comparison test. The results showed a better physicochemical property of the soil at the lower altitude. The intensification of pasture management and grazing through the utilization of rest periods of 45 days or less may represent a productive and low-emission option.

28 March 2023 in Revista Politécnica
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Journal Article
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Francisco GutiérrezFrancisco Gutiérrez
Francisco Gutiérrez
RARichard Bladimir Artos-García
Richard Bladimir Artos-García
APArnulfo Rigoberto Portilla
Arnulfo Rigoberto Portilla
La alimentación es el costo más importante en la producción animal. El objetivo de esta investigación fue comparar los métodos de secado en diferentes forrajes para la obtención de materia seca, horno con convección de aire (HC) y horno microondas (HM), y su efecto sobre la composición nutricional de cada forraje. Se estudiaron seis forrajes comúnmente utilizados en la producción animal: maíz duro amarillo (MA) (Zea mays), pasta de soya (PS) (Glycine max L.), rechazo de verde (RV) (Musa × paradisiaca), ensilaje de maíz (EM) , alfalfa (AL) (Medicago sativa) y raigrás perenne (RP) (Lolium perenne). Se analizaron 40 muestras de cada forraje, cada forraje fue secado en HC, así como en HM y se estimó el contenido de materia seca (MS), luego se le realizó un análisis bromatológico; Proteína bruta (Pb), extracto etéreo (EE), fibra bruta (Fb) y cenizas. Se utilizaron un análisis de varianza y prueba de Tukey (p<0.05) para determinar diferencias entre medias. Los resultados demuestran que existen diferencias (p<0.05) en el contenido de (MS), siendo el HM quien alcanza un mayor nivel de MS en MA, PS, RV y AL, el RP tuvo valores más altos con el HC mientras que en el EM el contenido de MS no varía con los métodos de secado. Los métodos de secado tuvieron incidencia en la composición química de los forrajes, así por ejemplo de los 6 forrajes analizados en la Pb se observó diferencias en 5, Fb en 3, EE en 1 y cenizas en 4. Livestock feeding is the most important cost in animal production. The objective of this research is to compare the drying methods on different forages for obtaining dried matter, convection oven (CO) and microwave oven (MO), and the effect of each method on the nutritional composition of each forage. Six types of forages, commonly used in animal production, were studied: yellow hard corn (YC) (Zea mays), soybean paste (SP) (Glycine max L.), banana reject (BR) (Musa × paradisiaca), corn silage (CS), alfalfa (AL) (Medicago sativa) and perenial ryegrass (PR) (Lolium perenne). 40 samples of each forage  were analized, each forage was dried using CO and MO, and the dried matter content was estimated, then a bromatological analysis was done. Crude protein (Cp), ethereal extract (EE), crude fiber (Cf) and ashes. A variance analysis and tukey test (p<0.05)  were used to determine differences between means.  Results show that differences  (p<0.05) exist in the content of DM, being that MO reaches the highest level of DM in YC, SP, BR and AL, the PR had higher values with the CO while in the CS the content of DM does not vary with the drying methods. The drying methods had incidence on the chemical composition of forages, for example of the six forages analized  in the Cp differences were observed in 5, Cf in 3, EE in 1 and ashes in 4.