Browsing by Author "Guevara Viera, Guillermo Null"

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Eficacia de la prueba Elisa en muestras de leche para la vigilancia epidemiológica de la brucelosis bovina
(Archivos Latinoamericanos de Producción Animal, 2022) Dután Sanango, Jorge Bolívar; Lupercio Novillo, Rosa Lucía; Andrade Guzmán, Omar Santiago; López Espinoza, Mateo Damián; Vintimilla Rojas, Andrea Elizabeth; Rivera Pirela, Sergio Emiro; Bustamante Ordóñez, Jorge Gualberto; Guevara Viera, Guillermo Null; Andrade Guzmán, Omar Santiago
Bovine brucellosis is a worldwide zoonotic disease capable of infecting cattle for long periods of time. Some animals are asymptomatic, thus maintaining the disease in the herd. Cattle become infected after ingestion of contaminated milk, feed, water; also by contact with infected animals, uterine secretions or aborted fetuses and by vertical transmission. Little is known about the epidemiological situation of brucellosis in dairy herds in the province of Azuay. An initial step for the formulation of control and eradication programs would be the implementation of a surveillance system that allows characterizing the state of infection in dairy areas, and thus early detection of the entry of the disease into free herds. The purpose of this study was to evaluate the efficacy of the indirect ELISA test (IDEXX, Brucella tank milk) in milk pools as a tool to identify herds that have not been in contact with the disease, allowing the characterization of areas free of brucellosis.
Estructura del pastizal, producción de leche y emisión de metano en vacas lecheras en pastoreo
(2021) Ortuño Barba, Carlos Luis; Faican Faican, Rosa Paola; Carangui Quintuña, Angel Bernardo; Cabrera Vazquez, Luis Geovanny; Guevara Viera, Raúl Victorino; Angamarca Padilla, María Alexandra; Patiño Puma, Paola Andrea; Narváez Terán, Jhonny Alfredo; Guevara Viera, Guillermo Null; García Zumalacarregui, Jorge Alejandro; Arcos Álvarez, Cristian Neptali; Lascano Armas, Paola Jael
The research was carried out at the IrquisExperimental Farm belonging to the University of Cuenca, Azuay province, Ecuador, at 2,663 meters above sea level with the following coordinates 1773890 E and 9659302 N, it is temperate climate, temperature between 8 and 14 ° C, relative humidity 80% and a rainfall of 639 mm / year. The research was carried out during 16 weeks, between the months of December 2018 to March 2019. The animal response was determined as milk production based on three botanical composition patterns, with a predominance of Kikuyo, in another with a predominance of Ryegrass and in another with an Association of these and White Clover. The structure of the grasslands was determined. The availability of forage was similar between the different types of grasslands, due to the time of study and that the components measured in the grassland had a compensatory effect, likewise the utilization in the Kikuyo pastures and the Ryegrass-Treból Association was better compared to Ryegrass. Milk production was higher in Kikuyo, most likely due toits better structure.
Morfometría de la gónada masculina y espermatozoides de cuyes (Cavia porcellus) nativos y mejorados del sur de Ecuador
(2021) Rosales Jaramillo, Cornelio Alejandro; Nieto Escandón, Pedro Emilio; Ayala Guanga, Luis Eduardo; Perea Ganchou, Fernando Pedro; Guevara Viera, Guillermo Null
The aim of this research was to describe the morphometry of the testicles and sperm of guinea pigs (Cavia porcellus) of two genetic groups, native and improved, from southern Ecuador. Twenty-two native and 20 improved guinea pigs of the Peru line were used. The animals were reared in elevated cages and fed with forage and concentrate, until reaching the slaughter age of 97 to 112 days. After slaughtering, the testicles and epididymis were removed, and the epididymis was separated of the testis. Measurements of the testicles were done, and sperm was collected from the epididymis by the retrograde flow washing technique. Semen smears were prepared for sperm measurements. The data were processed by GLM analysis of variance and the LSMeans procedure was used to compare the means (SAS v. 9.0). The morphometric parameters of the testes were different (p<0.05) between subpopulations. Opposite testes from the same genetic group were similar, while the ipsilateral ones between subpopulations showed statistical differences (p<0.05). Testicular size was directly related to body weight, and the gonadosomatic index of native guinea pigs was higher than that of improved ones (p<0.05). Spermatozoa were different (p<0.05) between genetic groups in acrosome and head length and in head length / width ratio. In conclusion, this study showed morphological differences in the testes and sperm between the two genetic groups of guinea pigs.
Morphological and histological characteristics of ovaries from two genetic groups of guinea pigs (Cavia porcellus) from South America
(2022) Perea Ganchou, Fernando Pedro
This study aimed to describe morphological and histological characteristics of ovaries of two genetic groups of guinea pigs from Latin America. Ovaries from 20 improved and 20 native guinea pigs were collected after slaughtering. One ovary from each animal was weighed, measured, counted for visible follicles on the ovarian surface, and used for subsequent oocyte collection by the slicing method. Contralateral ovaries were used to prepare histological sections and quantify follicles. Body and ovary weight and ovary length were significantly greater in improved than in native guinea pigs (p<0.01). Ovarian weight was greater in diestrus than in proestrus (p=0.0632) only in improved animals. The number of primordial, primary, secondary, and total follicles did not differ between genetic groups. The number of antral follicles was significantly greater in improved than in native guinea pigs. The thickness of zona pellucida and oocyte diameter did not differ between groups. The thickness of the zona pellucida was significantly greater in oocytes of category A than B and C in both groups of guinea pigs. In conclusion, ovaries from improved guinea pigs were heavier and longer than those from native animals. The number of antral follicles was greater in improved than native guinea pigs. Zona pellucida thickness and oocyte diameter were similar in both groups of guinea pigs.
Repetibilidad en rasgos productivos y reproductivo en una lechería de búfalas (Bubalus bubalis) en Ciego de Ávila, Cuba
(2019) Carrera Sáname, Odalis
Aim: To estimate the repeatability values of productive and reproductive traits on a dairy buffalo (Bubalus bubalis) Methods: A total of 257 observations were made to 34 river buffalo cows on a dairy buffalo (Bubalus bubalis) farm, at Ruta Invasora Cattle Company, in Ciego de Ávila, Cuba. The buffalo herds were naturally bred, and were manually milked between 4:00 and 6:00 am; the animals grazed on native and introduced grass all the year. One stud was used per of 30-40 cows. The reproduction data were collected from individual control charts, which included the calving number, weight at weaning (WW), initial weight (IW), calving-calving interval (CCI), and milk production (MP). SPSS, version 23, for Windows was used to estimate the repeatability of the variables studied (weight at weaning, reproduction weight at incorporation, calving interval, and milk production), according to the variance components by the general linear model for inter and intra cow variance components. Results: The repeatability values achieved were 0.41 ± 0.03 for WW; 0.50 ± 0.04 for IWM; 0.01 ± 0.03 for CCI; and 0.65 ± 0.06 for MP. Conclusion: High repeatability values for milk production occurred thanks to the absence of previous genetic selection.