Yuniel Méndez-Martínez

Universidad Técnica Estatal de Quevedo · Acuicultura / Facultad de Ciencias Pecuarias y Biológicas

The effect of dietary protein:energy (P/E) ratio on growth performance, body composition, digestive enzyme activities, hematology, and hepatopancreas histology was tested in the juvenile cauque river prawn Macrobrachium americanum. Six diets with two different crude protein levels (350 and 400 g kg− 1 diet) and three lipid levels (60, 100, and 140...

This study evaluated the effect of low, medium, and high-water salinity (5, 35, and 50 ppt) on the apparent dry matter, protein, and energy digestibility of two formulated and six commercial diets for juvenile whiteleg shrimp, Litopenaeus vannamei, in a 120-day trial. Digestibility was determined in vivo using chromic oxide as an inert diet marker....

The overuse of antibiotics in aquaculture has led to serious concerns on microbial resistance and chemical residues. Novel sources of immunostimulants could help to solve this problem by stimulating the immune system to fight against pathogens. Therefore, this study aims to explore the immunostimulant potential of Cystobacidium benthicum-β-glucans...

Objective. To evaluate the effect on biological, nutritional, and hematoimmune indicators of juvenile Cherax quadricarinatus were cultivated and fed with a probiotic mixture. Materials and methods. A completely randomized design (DCA) with six treatments: 0 (control), 1×102 μL, 2×102 μL, 3×102μL, 4×102 μL and 5×102 μL of a probiotic mixture (Bacter...

This study aimed to evaluate the growth performance, feed utilisation, digestive and metabolic enzyme activity, and liver histology in juveniles of hybrid red tilapia (Oreochromis mossambicus × Oreochromis niloticus) fed with the inclusion of chitosan in their diet. Six dietary chitosan levels (0 “control’’, 10, 20, 30, 40, and 50 g kg−1) were used...

Objective. To evaluate the nutritional composition of duckweed (DW) (Lemna minor) and water hyacinth (WH) (Eichhornia crassipes) and its effect on the apparent digestibility of dry matter (%, ADDM), apparent digestibility of crude protein (%, ADCP) and the apparent digestibility of the crude lipid (%, ADCL) in the nutrition of tilapia (Oreochromis...

Objective. To evaluate the nutritional composition of duckweed (DW) (Lemna minor) and water hyacinth (WH) (Eichhornia crassipes) and its effect on the apparent digestibility of dry matter (%, ADDM), apparent digestibility of crude protein (%, ADCP) and the apparent digestibility of the crude lipid (%, ADCL) in the nutrition of tilapia (Oreochromis...

The use of microorganisms isolated from the natural environment can improve the culture conditions in aquaculture systems and the immune and antioxidant response capacity of cultured organisms. In this study, the immunochemical response and gene expression of Litopenaeus vannamei juveniles were analyzed following exposure to microorganisms isolated...

The aquaculture due to the high cost and continued shortage of animal protein sources, the development of alternative plant protein sources has been one of the main challenges to establish sustainable aquaculture as economically viable. Objective of this investigation was to determine the chemical composition and effect of Tithonia diversifolia on...

Universities have been generators of knowledge. Thus, university professors should be integrated into research projects and academic networks of knowledge that allow them to strengthen scientific production. The objective of this study is to analyze the professors’ criteria in their participation in university processes and role in research project...

Objective. Characterizing the chemical composition of pre-dried chicken intestines with vegetable meal (VM), as an alternative source of protein for aquaculture. Materials and methods. Chicken intestines, grounded, cooked and defatted (CIGCD), were mixed individually with VM: rice powder (RP), wheat bran (WB), palm kernel cake (PKC), cornmeal (CM)...

With the objective of evaluating different biological and metabolic indicators in males and females Pseudocurimata boulengeri in three ecosystems of Los Ríos, Ecuador, specimens were captured in the areas of Ventana, Quevedo and Buena Fe (60 per area, 180 total), and proceeded to perform the sexing. The following were determined: size, weight, thic...

Dada la importancia de los peces de agua dulce en la dieta de los ecuatorianos, existe la imperiosa necesidad de conocer más acerca de la calidad de las carnes de las especies nativas de peces en el Ecuador; por ello se realizó el estudio comparativo de la composición nutricional, antioxidante y sensorial del campeche (Chaetostoma fischeri) y la ch...

In this study the enrichment dietary effect with different crude protein levels (CP) and feed additives on growth, survival, feed conversion ratio (FCR), feed consumption (FC) and total hemocyte count (THC) in juvenile white shrimp Litopenaeus vannamei were evaluated. The study covered two bioassays: in the first one, juveniles were daily fed for 4...

Administration of immunostimulants in fish is a preventive method to combat infections. A wide variety of these biological molecules exist, among which one of the yeast wall compounds stands out for its different biological activities. The β-glucan that forms the structural part of yeast is capable of generating immune activity in fish by cell rece...

Objective. To determine the response of the productive indicators when including palm (Elaeis guineensis) kernel cake (PKC) in diets for the nutrition of tilapia fry (Oreochromis niloticus). Material and methods. Three hundred sex-reversed males of tilapia (4.89±0.09 g) were used and distributed according to a completely random design for 60 days,...

There has recently been great concern for proper conservation and use of living natural resources where good management practices on aquaculture are mandatory. The economic and ecological importance of prawns of the Genus Macrobrachium cause an impact at a global level involving economic, academic and social aspects. Macrobrachium americanum appear...

The article analyzes from a reflective practice the elements of pertinence and demand of the Biology career at the State Technical University of Quevedo, Ecuador. It is pertinent because it is important, significant, and useful for sustainable development to contribute to the conservation of ecosystems and biodiversity of species, and therefore to...

Agroecology as a synthesis science for the construction of food sovereignty allows setting guidelines for the sustainability and development of a country. The relevance of the Master's Degree in Agroecology and Sustainable Development of the State Technical University of Ecuador is based on the solution of the main problems presented in agroecosyst...

El objetivo del estudio fue determinar la composición química, digestibilidad y rendimiento de Brachiaria decumbens a diferentes edades de rebrote. Las epocas fueron; poco lluvioso (Enero-Abril) y lluvioso (Julio-Octubre). Los tratamientos (edades de rebrote: 30, 45, 60, 75, 90 y 105 días) se distribuyeron en un diseño de bloques al azar con cuatro...

A comparative study of serum biochemical and hematological parameters from Andinoacara rivulatus and Ichthyoelephas humeralis in Los Ríos Province, Ecuador, was carried out. Two of the native species that are the most commercialized in Quevedo, Mocache and Fumisa, were identified; 60 specimens were captured in each area (180 total). A factorial des...

The objective of the research was to analyze the active methodologies and technological applications in the teaching-learning process in the transition from face-to-face to virtual, carried out as a consequence of the COVID-19 health emergency, in the educational institutions of Zone 1, 2, and 5 of Ecuador. The research focused on a quantitative st...

Objective: To evaluate the effects of the habitat and sex on the serum biochemical and morphometric response of I. humeralis in lotic ecosystems of Los Ríos province, Ecuador. Materials and Methods: one of the native species more commercialized in the cantons of Quevedo, Mocache and Fumisa of Los Ríos Province, I. humeralis, was identified and samp...

The effect of the habitat and sex on biological indicators and blood biochemistry of Andinoacara rivulatus in the province of Los Ríos-Ecuador was evaluated. Were captured 60 specimens for each zone (180 total), the eight of the animals, length, thickness of the head, tail and the factor were evaluated. Blood glucose, cholesterol and triglyceride i...

Objetivo. Evaluar los efectos de la zona de habitad y sexo en la respuesta bioquímica sérica y morfométrica de Ichthyoelephas humeralis en ecosistemas loticos de la provincia Los Ríos, Ecuador. Materiales y métodos. Se identificó una de las especies nativas (I. humeralis) que más se comercializan en los cantones de Quevedo, Mocache y Fumisa de la p...

Objective: To evaluate the effects of the habitat and sex on the serum biochemical and morphometric response of I. humeralis in lotic ecosystems of Los Ríos province, Ecuador. Materials and Methods: one of the native species more commercialized in the cantons of Quevedo, Mocache and Fumisa of Los Ríos Province, I. humeralis, was identified and samp...

The effect of the habitat and sex on biological indicators and blood biochemistry of Andinoacara rivulatus in the province of Los Ríos - Ecuador was evaluated. Were captured 60 specimens for each zone (180 total), the eight of the animals, length, thickness of the head, tail and the factor were evaluated. Blood glucose, cholesterol and triglyceride...

The master's program proposed by the Technical State University of Quevedo will contribute to the development of new knowledge to promote good aquaculture practices and train professionals with scientific and humanistic vision framed to the theoretical perspective raised in the objectives of the National Development Plan 2017-2021 - Toda una Vida,...

El programa de maestría propuesto por la Universidad Técnica Estatal de Quevedo contribuirá al desarrollo de nuevos conocimientos para fomentar buenas prácticas acuícolas y formar profesionales con visión científica y humanista enmarcados a la perspectiva teórica planteada en los objetivos del Plan Nacional de Desarrollo 2017-2021 - Toda una Vida,...

Cherax quadricarinatus or redclaw is considered a good option for freshwater aquaculture and has been cultivated in several countries. However, nutritional studies are scarce. In present research, the effects of different protein-energy (P/E) ratios in diets for male and female of pre-adults were investigated. Its influence on growth performance, c...

The use of biostimulants in fish diets is a promising strategy to reduce the use of antibiotics, enhance the biochemical and immune response, which contributes to improving productive yields and reducing economic losses. The biochemical and immune response was evaluated in juvenile red tilapia (Oreochromis mossambicus × O. niloticus), with diff...

Background: It was noted in 2012 that the Cenchrus genus absorbed the Pennisetum genus, within which grass varieties that accumulate a large amount of standing dry matter (DM) are currently included, which is favored by the rainfall regime and assistance with fertilizers. Objective: To evaluate the effect of different fertilization variants (NPK, f...

p> Background: It was noted in 2012 that the Cenchrus genus absorbed the Pennisetum genus, within which grass varieties that accumulate a large amount of standing dry matter (DM) are currently included, which is favored by the rainfall regime and assistance with fertilizers. Objective: To evaluate the effect of different fertilization variants (NPK...

Currently, the use of unconventional food sources in the inclusion of fish diets is cause of great interest. The growth performance of African catfish (Clarias gariepinus) was evaluated, with the inclusion of duckweed meal (Lemna perpusilla) in four levels (0, 6, 12 and 18 %) in the diet. African catfish with an average weight of 1.27 ± 0.03 g, wer...

Using a random block design with factorial arrangement (3x2) the effect of the climatic area (Guayas and El Empalme) in the yield components and bromatological composition of three Brachiaria varieties (Decumbens, Brizantha and Mulato I) was studied. The yields of total dry matter, biomass, leaves and stems, the plant height, length and width of le...

The objective of this work was to determine the effect of age and climate on the chemical composition of Cenchrus purpureus in degraded ecosystems of Cuba. An experiment was carried out in two welldefined periods: slightly rainy (January to April) and rainy (July to October). The treatments (regrowth ages: 30, 45, 60, 75, 90 105 days) were distribu...

This experiment has examined the effects of age of regrowth (60, 120 or 180 days) and season (dry or rainy period) on the nutritional quality of roughage from Erythrina variegata harvested in the Cauto Valley, Cuba. A randomized block design with three replicates was used. Proximate and mineral composition, in vitro and in situ dry matter digestibi...

Finding alternatives to deal with the lack of feed during the dry period is a challenge for animal research in tropical areas. The effect of age of regrowth (60, 120 or 180 days), chemical composition and secondary metabolites on Leucaena leucocephala digestibility was evaluated. A randomized block design with six replicates was used. The statistic...

An experiment in Acuipaso Station, Granma province, Cuba was carried out to evaluate the effect on growth and survival indicators of inclusion levels (0, 10, 20 and 30 %) of water fern meal (Azolla filiculoides) in diets for red tilapia hybrid small fish (Oreochromis mossambicus x O. niloticus). A completely randomized design with four treatments a...

The effect of climatic area (Guayas and El Empalme) on quality indicators of three varieties of Megathyrsus maximus (Common, Tanzania and Tobiatá) was studied using a random block design with factorial arrangement (3x2). Yields of total dry matter, biomass, leaves and stems were determined, as well as height of the plant, length and width of leaves...

Background. Background. The Moringa oleifera Lam is a fast growing deciduous tree. Objective. To evaluate under conditions of Cauto Valley, Cuba, the effect of the combination of cutting height with cutting age in morphological and productive variables in Moringa oleifera vc Criolla. Methodology. The evaluations were developed in a design of divide...

Coastal lagoons are an important component of the Gulf of California as they are considered natural ecosystems with high productivity and home to species of regional economic interest such as the striped mullet (Mugil cephalus), which, for its eating habits tends to present parasitism. The objective of the present work was to identify and determine...

This experiment has examined the effects of age of regrowth (60, 120 or 180 days) and season (dry or rainy period) on the nutritional quality of roughage from Erythrina variegata harvested in the Cauto Valley, Cuba. A randomized block design with three replicates was used. Proximate and mineral composition, in vitro and in situ dry matter digestibi...

With the objective of evaluating the yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador at different regrowth ages, the research was carried out, following a random block design with factorial arrangement (3x3) with five replications. The productivity (yields of total dry matter, leaves, s...

The objective of this study was to evaluate the forage quality and productivity of Cenchrus purpureus cultivars grown in Ecuador, Maná zone. Varieties of Cenchrus purpureus cv Purple and Maralfalfa were used in different ages of regrowth (45, 60, 75 and 90 days) distributed in a randomized block design of random effects in factorial arrangement wit...

The environmental problems that plague humanity are urgent to be solved. Therefore, professionals are required to be trained under an ethical conscience with respect to the current situation of the environment. The objective of this work is to show a set of actions so that the students of the Zootechnics career can identify and act from the subject...

An experiment in Acuipaso Station, Granma province, Cuba was carried out to evaluate the effect on growth and survival indicators of inclusion levels (0, 10, 20 and 30 %) of water fern meal (Azolla filiculoides) in diets for red tilapia hybrid small fish (Oreochromis mossambicus x O. niloticus). A completely randomized design with four treatments a...

El uso de bacterias probióticas como agentes de control biológico ha sido efectivo, sin embargo, los trabajos se han centrado en la aplicación de manera individual, sin tomar en cuenta que las mezclas podrían potenciar los efectos. En este trabajo se evaluaron mezclas de bacterias con potencial probiótico sobre larvas y juveniles de Argopecten vent...

With the objective of evaluating the yield components and bromatological composition of three Megathyrsus maximus cultivars in Guayas area, Ecuador at different regrowth ages, the research was carried out, following a random block design with factorial arrangement (3x3) with five replications. The productivity (yields of total dry matter, leaves, s...

Currently in agriculture, the search for products that favor the growth and development of crops, as well as the increase in their yield such as rice (Oryza sativa L.) is a cause of work. In addition, these compounds are of natural origin, biodegradable, biocompatible, have a low cost and do not cause damage to the environment. This is the case of...

Using a random block design with factorial arrangement (3x3) with five replications, the quality of Bra- chiaria decumbens, Brachiaria brizantha and Brachiaria decumbens x Brachiaria ruziziensis cv. Mulato I at different regrowth ages (21, 42 and 63 days) were evaluated in Guayas area, Ecuador. The yields of total dry matter, biomass, leaves and st...

In order to evaluate the effect of partial substitution of commercial concentrate (CC) for Azolla filiculoides (HA) meal in rabbit productive indicators (Oryctolagus cuniculus), a completely randomized design was used with 48 animals of 35 days old and mean weight of 646.3 ± 9.5 g. This study was carried out in Río Cauto municipality, Granma provin...

Mediante un diseño bloque al azar con arreglo factorial (3x3) con cinco réplicas se estudiaron los componentes del rendimiento y composición bromatológica de tres variedades de Brachiaria (Decumbens, Brizantha y Mulato l) y tres edades de rebrote (21, 42 y 63 días) en la zona El Empalme, Ecuador. Se determinaron los rendimientos de materia seca tot...

In order to determine the effect of regrowth age on the components of yield, chemical composition and polyphenolic profile of Tithonia diversifolia, an experiment was carried out using a randomized block design with four replications in brown soil with carbonate. The treatments consisted of three regrowth ages (60, 120 and 180 days). To establish t...

Using a random block design with factorial arrangement (3x3) with five replications, the yields and quality of three Megathyrsus maximus cultivars (Common, Tanzania and Tobiata) and three regrowth ages (21, 42 and 63 days) were studied in the Empalme area, Ecuador. The yields of total dry matter, biomass, leaves and stems were determined, as well a...

Plains grass is a robust and useful forage grass of African origin, very persistent and a wide range of adaptation to edaphoclimatic conditions. The present investigation was carried out in the months of July-September 2015, on a farm, located at Km one of the El Empalme-Balzar road, province of Guayas, Ecuador. With the objective to evaluate the e...

In the tropics, the planting of improved species for the production of green fodder has attained great importance due to its potential. The present investigation was carried out in the months of July-September 2015, on a farm, located at Km one of the El Empalme-Balzar road, province of Guayas, Ecuador. With the objective of evaluating the effect o...

Honey grass is a perennial species, very persistent and a wide range of adaptation to edaphoclimatic conditions. The present investigation was carried out in the months of July-September 2015, on a farm, located at Km one of the El Empalme-Balzar road, province of Guayas, Ecuador. with the objective to determine the effect of maturity on the chemic...

Using a random block design with four replications, the effect of regrowth age (60, 90, 120, 150 and 180 days) on the bromatological composition of Moringa oleifera foliage was evaluated in both seasons. The sampling took place in plots of 0.5 ha, to which a uniformity cut of one meter above the soil, without irrigation or fertilization, was applie...

The nutritional value of nauplii and metanauplii I of Artemia enriched with microalgae as food for freshwater prawn larvae (Macrobrachium americanum) was tested. The larvae were fed with three different diets consisting of Artemia nauplii (D1), Artemia metanauplii I enriched with Tetraselmis suecica (D2), and Artemia metanauplii I enriched with Cha...

The effect of different proteins and lipids levels on antioxidant response of superoxide dismutase (SOD) was tested in muscle, hepatopancreas and whole-body tissues of cauque river prawn Macrobrachium americanum juvenile. Six diets with two crude protein (35 and 40% diet) and three lipid levels (6, 10, and 14% diet) were tested for juveniles in a f...

The effect of five diets with different crude protein levels (27, 33, 38, 43, and 48%) on growth and survival of Macrobrachium americanum prawns was determined. Optimum dietary protein level was also calculated. Specimens were collected in the Coyuca River, Guerrero, Mexico, and classified into seven weight groups with 0.67 g intervals amplitude. F...

In aquaculture it is necessary to develop other feeding alternatives, as a consequence of the demand and high costs of nutrients. Therefore the objectives of this work were to determine the chemical composition of Elodea dense meal (HEd), and the biological response of African catfish (Clarias gariepinus) in its second stage of nursery, to include...

En la acuicultura el incremento de los precios de los alimentos, irregularidad en el suministro y escasez de los mismos, constituyen nuevos riesgos que pueden poner en peligro el funcionamiento de este sector. La demanda de piensos acuícolas mantendrá su escalada y por lo tanto, lo mismo sucederá con la harina de pescado dado a que es el insumo más...

La búsqueda de formas de producción animal adecuadas ha sido tema de interés en diversos fórums en el cursar de los años. Destacándose el cultivo de la tilapia roja, la cual se ha convertido en uno de los peces más comercializados en el ámbito internacional. En el presente documento, se ofrece una visión general del cultivo de tilapia roja (Oreochr...

Tthe advantage of aquatic species is the high production of foliage, the high protein content and the decontaminating capacity of these plants as a waste treatment pathway. The present investigation was developed between the months of January - March of 2012, in the UBPC Guamo Viejo, Río Cauto, Granma; with the objective to evaluate the effect of o...

Mathematical models and in particular those applied to biology, can be an important tool to understand the dynamics of a phenomenon. In the science of pastures they play an important role in the study of this, which is reflected in the growing number of publications on the subject. In order to establish the relationship of the age of regrowth on co...

The use of trees and shrubs are booming in animal production systems, due to their variety of uses, specifically for their productive potential throughout the year on a sustained basis. In order to determine the effect of age on the performance of Gliricidia sepium, the experiment was developed, following a randomized block design, with five treatm...

The Azolla sp., it is not of universal use in the animal, but well used feeding it can become an important element in the sustainable systems of production acuícola, by virtue of their low cost. The present work was developed in the Station Acuipaso, county of Granma, Cuba, with the objective of evaluating the effect of the inclusion (0, 6; 12 and...

The potential of the grasses for the production of milk and meat is defined by the quality and the capacity of emitting biomass of forage. The present investigation was developed among the months of June to August of 2015, Property Anabel", Canton The Manna", in the parish Guasaganda, county of Cotopaxi, Ecuador; they were determined the effect of...

En la acuicultura el incremento de los precios de los alimentos, irregularidad en el suministro y escasez de los mismos, constituyen nuevos riesgos que pueden poner en peligro el funcionamiento de este sector. La demanda de piensos acuícolas mantendrá su escalada y por lo tanto, lo mismo sucederá con la harina de pescado dado a que es el insumo más...

La Azolla filiculoides is an alternative for the development of sustainable systems, which stands out for its high protein value. The present investigation was developed in the UBPC of Guamo Viejo, Río Cauto, Granma. The experimental phase was from February to July, with the objective of evaluating the production of this macrophyte with the use of...

At present, beneficial microorganisms are used in shrimp culture to control potential bacterial pathogens and to increase productive response. The objective of this study was to evaluate the effect of Bacterol-SHRIMP on juveniles of Litopenaeus vannamei for the prevention of diseases and to promote adequate yields, absolute growth, daily weight gai...

We determined the effect of four concentrations of dietary crude protein, 30.7, 37.2, 41.8 and 46.8% on growth rate, survival and body composition of the juvenile cauque river prawn (Macrobrachium ameri-canum). The prawns were hatched in the laboratory from the spawn of one wild ovigerous female. Prawns consuming 37.2% crude protein reached a final...