Browsing by Author "Maldonado Rivera, Jaime Eduardo"

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Bovine neosporosis in dairy cattle from the southern highlands of Ecuador
(2020) Maldonado Rivera, Jaime Eduardo; Vallecillo Maza, Antonio Javier; Perez Meneses, Cinthya Lizbeth; Cirone, Karina; Dorsch, Matías; Morrell, Eleonora Lidia; Scioli, Valeria; Hecker, Yanina Paola; Fiorani, Franco; Cantón, Germán José; Moore, Dadín
The aim of this study was to describe bovine neosporosis in dairy cattle from the Sierra region, Ecuador. A case-control study was performed on 841 dairy cattle from 5 dairy herds. The overall seroprevalence was 23.4% having significant association between abortion and seropositivity (p < .05). Additionally, 46 fetuses were recovered from a local slaughterhouse to evaluate the frequency of vertical transmission. Seventeen and 3 fetuses were positive by PCR and had compatible histopathological lesions, respectively. N. caninum infection must be considered as a relevant cause of reproductive losses in Ecuador.
Comportamiento y bienestar animal de la vaca lechera y su relación con la eficiencia reproductiva
(2011) Piedra Matute, Alexandra Elizabeth; Maldonado Rivera, Jaime Eduardo
La concentración de betahidroxibutirato (BHB) sanguíneo como predictor de la ciclicidad y el anestro de vacas lecheras posparto, en pastoreo
(2017) Lema Guamán, Víctor Manuel; Maldonado Rivera, Jaime Eduardo
The project was carried out at “LA Esmeralda” farm of the Biblián city, Cañar province. The aim of this research was to establish if is possible to use the blood concentration of β-hydroxybutyrate (BHB) of dairy cows as a predictor of postpartum ovarian activity (cyclicity and anestrus). We used 40 cows in transition period, clinically healthy, with similar condition of handling and feeding. BHB measurement was performed at 7, 14, 21, 28 and 35 pospartum days (DPP). Ovarian activity was assessed by ultrasonography at 21, 28 and 35 DPP. Statistics assay was performed using Chi-squarer test, correlation coefficient of Kendall’s Tau_b and the ROC curve. The result showed that there is not dependence between the type of anestrus and BHB’s concentration, however the highest concentration of this metabolite were found in type III and IV anestrus. We concluded that the concentration of BHB has low predictive power of the reproductive status of the cows as well as the type of anestrus present in the animals up to 35 DPP.
Detección del virus rábico en glándula parótida de ratones CD-1 inoculados con diferentes dosis de virus estándar de desafío (CVS)
(2017) Quezada Alvarado, Juan Diego; Maldonado Rivera, Jaime Eduardo
The present work is entitled "Detection of rabies virus in the parotid gland of CD-1 mice inoculated with different doses of Standard Challenge Virus". It was carried out in the laboratory of the National Institute of Public Health Research - Leopoldo Izquieta Pérez - Austro Regional. The present work aims to evaluate the use of parotid tissue for the detection of rabies virus using direct immunofluorescence in CD-1 mice after experimental inoculation in the brain with several doses of standard challenge virus. The standard technique of intracerebral inoculation with Standard Virus of Challenge was used for the diagnosis of rabies virus. Four groups of 20 mice were formed with different doses of antigen; detection of virus in imprints of the brain and parotid tissue was performed by direct immunofluorescence. To determine the association of factors under study (tissue, time and dose of standard virus), the following calculations were performed: Chi-square, Fisher exact test and binary logistic regression. The type of tissue, the antigen doses and the time of detection of the rabies virus did not show any significant difference. This led to the conclusion that it is possible to use parotid tissue for the detection of rabies virus in CD-1 mice.
Efecto de la administración de aceite de cáñamo Cannabis sativa (CBD) sobre el índice fagocítico en perros domésticos Canis lupus familiaris
(Universidad de Cuenca, 2023-11-14) Calle Moscoso, Ximena Karina; Maldonado Rivera, Jaime Eduardo
The aim of this study was to evaluate the modulatory effect of hemp essential oil CBD, derived from Cannabis sativa, on the phagocytosis index (FI) in domestic dogs (Canis lupus familiaris). Twenty dogs were studied, distributed among females, males, adults and geronts: the dogs received CBD orally at a rate of 2.5 mg/kg/12h for 21 days. Phagocytic cells and IF were determined at three times during the study (day 0, day 10, day 21). The variance of the data was analyzed using Student's t-test for paired and independent samples and chi-squared test to determine the association between IF values and the independent variables sex and age. Highly significant differences were obtained in the phagocytic cells of activated and inactivated serum. There was no significant difference in IF between adult dogs vs. geronts; and females vs. males. The administration of CBD significantly reduces the activity of phagocytic cells in peripheral blood of dogs, the IF did not present changes, since the activity of CBD reduces phagocytic cells both in those cultured in activated and inactivated serum; as for the age and sex factors, it was considered that these factors do not interfere with CBD in relation to the modulation of phagocytosis through pathways independent of complement activation and/or the reduction in the expression of receptors for opsonins.
Efecto de la vacunación a IBR con virus vivo y muerto, sobre las características anatómicas y endocrinológicas del cuerpo lúteo en novillas Holstein mestizas.
(2017) Castro Guaman, Walter Efraín; Maldonado Rivera, Jaime Eduardo
The present study was made to determine if the vaccination with bovine virus herpes type 1(HVB-1) such as prophylaxis for the infectious bovine rhinotracheitis has an effect about some characteristics anatomical and endocrinologic of the corpus luteum in mestizo Holstein heifers in the Ecuadorian Amazon of different cattle ranches in Saint Claire City, Pastaza province. It determines the corpus luteum diameter in differents developing phases using trans-rectal ultrasound and the concentration of progesterone in the blood, by enzimatic immunoassay in the Biomicrovet veterinarian clinic laboratory. Sixty heifers were used shared in three groups of 20 animals for the application of alive virus vaccine Cattlemaster(T2), a death virus Hiprovis-4(T3) and without immunogenetic (T1). For the experiment management all the groups were subjected synchronizing protocol with progestogen and estradiol. Meaninful statistics differences were observed in the average diameter of the corpu luteum at the 12 and 18 days, being stil far the treatment 1 witness (26,5 mm and 29,9 mm) respectevely continued of the treatment 2 alive virus with (19,5mm and 17,9mm) and the treatment 3 death virus with (19,2mm and 17,9mm). The blood concentration of progesterone was statistically higher to the 12 and 18 days post- treatment in the treatment 1 witness (5,1 and 5,7 ng/dl) followed for thebtreatment 2 alive virus (3,2 and 2,8 ng/dl) and the treatment 3 death virus (3,1 and 2,8 ng/dl) and there is not differen statistically value in the 3 treatments in study. To vaccinate the animals with bovine virus herpes type 1 has effects above the early development of corpus luteum in heifers, it was found that the blood progesterone concentration varied significantly in the present investigative work.
Efecto de los aceites de oliva y soya ozonizados en la cicatrización de heridas postquirúrgicas en perros
(2017) Quizhpilema Palaguachi, Diana Maricela; Orellana Parra, José Luis; Maldonado Rivera, Jaime Eduardo
Some clinical and experimental studies have suggested a beneficial effect of the administration of ozone in different animal diseases. The purpose of the present study was to evaluate the effect of topical use of ozonated vegetable oils on the healing of postsurgical wounds in dogs; There are no investigations in this regard. In the experiments the sample was homogeneous of 32 half-blood male dogs, with a body condition of 3/5, from one to five years, all underwent a prescrotal orchiectomy (ORH) with an incision three centimeters long; Four groups were formed: A, B, C, D with eight animals in each. The treatments used were: Group A: ozonized olive oil (50 μg / ml), B: ozone-free olive oil, C: ozonized soybean oil (50 μg / ml) and D: ozone-free soybean oil. All groups received 1 ml of the compounds every 12 hours for seven days topically. RESVECH V1.0 scale at 0, 2, 4 and 6 was used to evaluate macroscopic healing. Postoperative cytological studies were performed on days 1, 3 and 5. The results showed that the topical application of the product did not have a statistically significant effect. However, numerically with the RESVECH V.1.0 scale, 96.95% of patients achieved a good healing range and 3.05% with bad healing. As for cytology, the presence of polymorphonuclear cells was evaluated, with 93.8% at day 1 and 3, at day 5 at 75% indicating that healing progresses normally for all treatments without difference. In as much the presence epithelial cells, fibrin and bacteria is independent to the treatments applied.
Efectos de la avidez de anticuerpos lgG sobre la tasa de transferencia congénita de neospora caninum en vacas lecheras
(2017) Taboada Pico, Mentor Guillermo; Maldonado Rivera, Jaime Eduardo
The objective of this research was: To determine the congenital transfer rate of Neospora caninum, in seropositive cows, according to the avidity of the IgG antibodies. It was carried out in three dairy herds in the provinces of Azuay and Cañar, in the southern highlands of Ecuador, Where abortions and reproductive problems have been reported, 148 dairy cows were selected, pregnant in the last third of gestation, Their serological status was determined by indirect ELISA enzyme immunoassay, to obtain the 40 cows positive to Neospora Caninum, Which would form part of the study. To determine the avidity of the IgG antibodies, the protocol was modified to each cow of the 40 will be performed another ELISA, With the modified protocol for avidity. To the blood of calves will be carried out 2 ELISA tests with the normal protocol of affinity and avidity. This will allow to know the protective effect of the natural antibodies in dairy cattle with high and low avidity against the vertical transmission of the parasite in the conditions of production of the Ecuadorian sierra.
Epidemiología y diagnóstico de la paratuberculosis bovina
(2009) Farfán Patiño, Diana Lucía; Maldonado Rivera, Jaime Eduardo
Epidemiologia, diagnóstico y control de la rinotraqueitis infecciosa bovina IBR
(2009) Ramírez Alvarez, María Paz; Maldonado Rivera, Jaime Eduardo
Epidemiología, diagnóstico y control de leptospirosis bovina
(2009) Barros Angulo, Sonia Janneth; Maldonado Rivera, Jaime Eduardo
Establecimiento de cultivos primarios de células endometriales y oviductales bovinas
(Universidad de Cuenca, 2024-08-05) Serpa Quito, Adriana Carolina; Maldonado Rivera, Jaime Eduardo
Currently, primary cell cultures are widely used for various research purposes, thereby reducing the reliance on laboratory animals. The aim of this investigation is to develop a standard protocol for primary cell culture of bovine endometrial and oviductal cells suitable for the conditions of the School of Agricultural Science labs at Universidad de Cuenca. We utilized endometrial and oviductal bovine cells, subjecting them to different treatments including modifications to their culture medium such as bovine fetal serum (BFS), pyruvate, and antibiotics. A total of 5 uteri in the luteal phase were collected, from which cells were extracted for endometrial cultures (n=12) and oviductal cultures (n=12). Endometrial cells were cultured for 14 days, while oviductal cells were cultured for 8 days. Analyses including assessment of confluence, cellular vitality, and well contamination were conducted on specified days using vital staining and Gram staining. However, observation and culture medium changes were performed every 48 hours. The results indicated the influence of the applied treatments on cellular vitality for both endometrial and oviductal cells (p < 0.05). While cellular confluence and well contamination in endometrial cell cultures were not affected by the treatments applied (p > 0.05), confluence and well contamination in oviductal cells exhibited statistical differences among treatments (p < 0.05). In summary, an initial assay of a cell culture protocol was successfully conducted under the conditions of the Agricultural School laboratory. However, further refinement of this technique is necessary to enable the pursuit of more complex research inquiries using primary cell culture methods
Estatus bacteriológico de sistemas lecheros mediante análisis de leche de tanque asociado con la rutina de ordeño y sanitización de equipos en las provincias de Cañar y Azuay
(Universidad de Cuenca, 2025-03-12) Carchi Galán, Bernardo Sebastian; Meyer Quito, Nicola; Maldonado Rivera, Jaime Eduardo
Since the 1970s, bulk tank milk analysis (BTMA) has become increasingly important in identifying pathogens responsible for mastitis. It has also been shown that it can be used to monitor the health of dairy herd udders. In this way, we identify bacteria referred to as colony- forming units (CFUs) and correlate them with milking routines, equipment cleaning, and mammary gland infection. The most important of these include Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli, and Enterococcus spp. This study was conducted on 40 dairy farms in the Azuay and Cañar regions, collecting necessary samples for bacteriological and somatic cell analysis. To ensure sample homogeneity and preserve the cold chain, the samples were taken after the morning milking, and after the sampling, a survey was conducted with the farm manager to record data about the farm, the milking routine, and equipment maintenance. The aim was to correlate bacteriological counts with milking and sanitation practices, thereby demonstrating its usefulness as a monitoring and control tool. For statistical analysis, both the survey and laboratory data were considered, finding associations between categorical variables, which helped establish significant relationships between milking routines and the likelihood of increasing, maintaining, or reducing colony- forming units whose presence affects the quality and value of the milk.
Falla en la transferencia de inmunidad pasiva maternal en ganado bovino lechero de la sierra sur del Ecuador
(Universidad de Cuenca, 2024-07-24) Fajardo Arcentales, Rosa Graciela; Ochoa Muñoz, Ana María; Maldonado Rivera, Jaime Eduardo
This research was carried out with samples from dairy producers located in the provinces of Azuay and Cañar. The general objective of the thesis was to determine the frequency with which passive maternal immunity transfer failure (FTIP) occurs in dairy cattle in the southern highlands of Ecuador. Producers were considered as both small and large holders. A total of 120 births were analyzed, from which blood samples were taken from calves within the first week of life (females and males) collected from the jugular vein with a vacuum blood collection system, in 9 ml tubes without anticoagulant. The samples were processed to extract the blood serum. 2 aliquots were separated for analysis: total serum proteins by refractometry and total proteins, albumin and globulin by spectrophotometry. 300 ml of colostrum was also collected from the mothers to measure its specific gravity and sugar concentration. There was a frequency of 26.36% of animals with maternal passive immunodeficiency transfer failure. No influence was found for sex, parity, type of farm, and differences for colostrum density and territorial origin. The concentration of globulins in the "Protected" individuals was higher than that of those suffering from FTIPM. All analysis showed a high relationship between the measurements made by spectrophotometry and refractometry. However, that relationship between colostrum quality measurements obtained by densitometry and Brix refractometry was low
Frecuencia de anticuerpos anti Neospora caninum en perros que conviven con bovinos de leche y carne
(Universidad de Cuenca, 2023-08-02) Hidalgo Núñez, Adriana Madelein; Romero Tigmasa, Wilson Fabricio; Maldonado Rivera, Jaime Eduardo
In Ecuador, epidemiological studies have been carried out that demonstrate the presence of the disease in cattle, its association with abortion, the presence of compatible lesions and genetic material of the parasite in slaughterhouse fetuses, although the prevalence is variable and has been reported. about 23.5%. However, there was no information to know the frequency of tests against Neospora caninum in dogs, considering that this species is the definitive host of the parasite. This study aimed to determine the frequency of anti-Neospora caninum studies in serum samples from 124 dogs living with cattle, taken from 59 farms in the Azuay, Cañar, Manabí and Santo Domingo de los Tsáchilas provinces. Variables were considered; sample origin, age, dogs sex, size and type of cattle herd, to determine if these factors are associated with the presence of anti-Neospora caninum studies. Data collection was carried out in a registration sheet that includes: location, data of the animal as well as the owner. Presence of anti Neospora caninum studies was developed by competitive ELISA, a frequency of 18.5% of the dogs studied was found. Statistical association will be developed, with the type of cattle herd and with the geographical region, the disease being more frequent in dogs that live in the mountains and coexist with dairy cattle. No statistical association was established with the variables size of the livestock establishment, age and sex of the dogs.
Identificación de Prototheca spp. en leche de tanque de ganaderías en las provincias de Azuay y Cañar de la sierra sur del Ecuador
(2025-02-06) Barahona Nacipucha, Kelly Jadira; Maldonado Rivera, Jaime Eduardo
In the dairy industry, the most common disease is mastitis, caused by various pathogens, especially bacterial ones. However, there are other less well-known pathogens such as achlorophyllous algae of the Prototheca genus, widely distributed in the environment, which have become relevant as causes of clinical and subclinical mastitis in cattle, generating economic losses for producers, since it does not respond to antibiotic treatments and can also cause disseminated infections in other animals and even humans. This study aimed to identify the presence of Prototheca spp. in cold-tank milk samples collected on farms in the provinces of Azuay and Cañar in the southern highlands of Ecuador. To do this, 33 milk samples were analyzed using two techniques for the identification of Prototheca spp: microbiological culture and polymerase chain reaction (PCR). Of the samples analyzed, 84.85% (28/33) showed growth of compatible or similar colonies; However, 27.27% (9/33) showed microscopic structures consistent with Prototheca spp. Prototheca spp. DNA was amplified by PCR in 11 samples, indicating a frequency of 33.33%. On the other hand, the variables, origin of the samples, sampling area (cold or warm), dairy herd size, average production and water quality, were evaluated by means of statistical association tests (Pearson and Fisher Chi-square). In addition, the concordance of the identification techniques was assessed by means of Cohen's Kappa test. The results show that there was no significant association between the presence of Prototheca spp. and the variables evaluated and there is no relevant concordance between the two diagnostic techniques. This is one of the first studies in the southern highland region of Ecuador that investigates the presence of Prototheca spp. in tank milk, using microbiological and molecular methods.
Innate and humoral immune parameters at delivery in colostrum and calves from heifers experimentally infected with Neospora caninum
(2021) Maldonado Rivera, Jaime Eduardo; Hecker, Yanina Paola; Burucúa, Mercedes M; Cirone, Karina Mariela; Cheuquepán, Felipe A; Fiorani, Franco; Dorsch, Matías A.; Colque, L A; Cantón, Germán José; Marín, Maia Solange; Moore, Dadin Prando
Neospora caninum is a leading cause of abortion in cattle worldwide. The study of the immune response against N. caninum is critical to understand its epidemiology, pathogenesis, diagnosis and, ultimately, in preventing and controlling bovine neosporosis. Herein, we determined the gene expression of innate immune components endosomal RNA-sensing TLRs, BMAP28 cathelicidin, TNF-α and IL-10 and characterized the variation in both IgG ratio and avidity at delivery in N. caninum-infected heifers challenged at day 210 of gestation, colostrum and their calves. Increased BMAP28 expression was observed not only in colostrum but also in peripheral blood mononuclear cells (PBMC) and umbilical cord of calves from N. caninum-infected heifers in comparison with mock-infected control group. In addition, statistically significant decrease of TLR7 and IL-10 expression levels were observed in umbilical cord, suggesting an attempt to avoid an exacerbated immune response against the parasite. At delivery, serum and colostrum samples from infected group evidenced specific IgG anti-N. caninum. Infected heifers showed IgG1/IgG2 ratios <1 and high avidity specific IgG. As expected, colostrum samples of these animals exhibited a high IgG1 concentration and elevated avidity values. Three out of four calves from N. caninum-infected heifers had specific IgG with IgG1/IgG2 ratios>1 and lower avidity values before colostrum intake. Interestingly, both IgG1/IgG2 ratios and avidity values increased in seropositive calves after colostrum intake. Overall, this study provides novel information on neonatal immunity in congenitally infected calves, which is essential to understand how the immune pathways could be manipulated or immune components could be employed in order to improve protection against neosporosis.
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.
Neonatología en bovinos de leche
(2012) Polo Martínez, David Fernando; Maldonado Rivera, Jaime Eduardo
Obtaining recombinant proteins from Neosporacaninum expressed in Escherichia coli
(2022) Maldonado Rivera, Jaime Eduardo; Vallecillo Maza, Antonio Javier