Preliminary Evaluation of the Effectiveness of the GAVAC® Immunogen and the Rational Use of Acaricides as an Alternative for an Integrated Tick Control Program in Ecuador

Rhipicephalus microplus one of the ectoparasites with the most significant impact on livestock health and the economy in Ecuador and globally. Controlling ticks through chemical means has been demonstrated to be ineffective, resulting in acaricide resistance and increasing costs and health problems in tropical and subtropical livestock. Several tick control alternatives have been investigated to date, showing promising results under laboratory conditions but not in field applications. The use of multiple control alternatives in a comprehensive management plan for tick control has proven to be effective in reducing tick infestation. The objective of this study was to determine the effectiveness of immunization with the Gavac® vaccine and its effect on the rational use of acaricides. The study aimed to establish the impact of immunization on the biotic potential of Rhipicephalus microplus, the level of infestation, and the frequency of acaricidal baths. In a pilot farm, 176 bovines were vaccinated, and 30 animals were observed every 15 days for eight months, resulting in 18 observations. Observationally, a significant reduction in tick load on animals was identified, as well as a reduction in the use of acaricides by less than 10% (1 bath) compared to the farm’s estimated use. On average, acaricidal baths were administered 23 days after vaccination. The study found a statistically significant decrease in the number of ticks on the animals, the weight of the eggs, and their hatching percentage after the inclusion of the vaccination program on the farm. However, no statistically significant effect on the weight of engorged ticks was observed. In conclusion, the Gavac® vaccine has a positive observational effect on controlling the presence of ticks in animals and a negative effect on their reproductive aspects. Keywords: Rhipicephalus microplus; vaccine; bovines; acaricide control; integrated tick control program. Resumen Rhipicephalus microplus es considerado como uno de los ectoparásitos de mayor impacto sanitario y económico en las ganaderías del Ecuador y del mundo. En la actualidad, se ha demostrado que los métodos de control químico son poco eficientes y generan resistencias a los acaricidas en las garrapatas; aumentando los costos y los problemas sanitarios en las ganaderías tropicales y subtropicales. Hasta la presente fecha se han investigado varias alternativas de control para las garrapatas con buenos resultados en condiciones de laboratorio; no así, en su aplicación en el campo. El uso combinado y técnico de dos o más alternativas de control ha mostrado buenos resultados en la disminución de las garrapatas dentro de un “plan de manejo integral para el control de las garrapatas”. El objetivo de este estudio fue determinar la efectividad de la inmunización con la vacuna Gavac® y su efecto en el uso racional de acaricidas; estableciendo el impacto de la inmunización sobre el potencial biótico de Rh. microplus, el nivel de infestación y la frecuencia de los baños acaricidas. En una finca piloto se vacunaron a 176 bovinos; de los cuales, 30 animales fueron observados cada 15 días por 8 meses (18 observaciones). Observacionalmente, se identificó una reducción significativa de la carga de garrapatas en los animales; así como, una reducción del uso de acaricidas menor al 10% (1 baño) en comparación con lo estimado por la finca. El promedio por baño acaricida fue de 23 días tras la vacunación. Se obtuvo una disminución estadísticamente significativa en el número de garrapatas sobre los animales, el peso de los huevos y su porcentaje de eclosión tras la inclusión del programa en el predio. No se observó un efecto estadísticamente significativo en el peso de las garrapatas ingurgitadas. En conclusión, la vacuna tiene un efecto positivo observacional sobre el control de la presencia de las garrapatas en los animales y un efecto negativo en los aspectos reproductivos de las mismas. Palabras Clave: Rhipicephalus microplus; vacuna; bovinos; control acaricida; plan de manejo integrado

Validación de dos activadores prebióticos en el desarrollo de terneras medias Ayrshire sobre los 3,000 m.s.n.m. en Sangolquí, Pichincha

The validation of two prebiotic activators in crossbred Ayrshire heifers was conducted in the province of Pichincha, Rumiñahui County, Rumipamba Parish, at 3,000 meters a.s.l. For the field phase, purebred Ayrshire heifers with an average age of 4 to 6 months old were studied and data on their weight, height and waist diameter increase, as well as their body capacity were measured every two weeks. An experimental design (DCA) with covariables, the age being the covariable, consisted of three treatments and five observations for each treatment. The experimental unit was the heifer. According to the analysis of variance conducted for each tested variable, there are no significant differences between treatments; however, for the analysis of the covariable (ANOVA), significant differences were detected for the interaction of each variable.En la provincia de Pichincha, cantón Rumiñahui, parroquia Rumipamba, sobre los 3,000 m.s.n.m., se llevó a cabo la validación de dos activadores prebióticos en terneras medias Ayrshire. Para la fase de campo se emplearon terneras puras con una edad de entre 4-6 meses de edad. Las variables dependientes fueron: e incremento de peso, altura, diámetro de cinchera y capacidad corporal; los datos se registraron cada 15 días. Se empleó un diseño completamente al azar (DCA) con covariables, el mismo que estuvo conformado por tres tratamientos y cinco observaciones para cada tratamiento, cada ternera fue una unidad experimental. De acuerdo al análisis de varianza realizado para cada variable evaluada se observa que no existen diferencias significativas entre los tratamientos; pero para el análisis de la covariable el ANOVA detectó diferencias significativas para la interacción de cada variable

Evaluación de factores de riesgo que afectan la mortalidad en pollos de engorde durante el proceso de traslado granja-planta de faenamiento en el centro norte de la región interandina

Millions of broiler chickens are transported annually from farms to the laughterhouse along the way, chickens are exposed to a wide variety of stressors such as food restriction, capture and transport, which affect animal welfare and cause live weight losses to death, which economically impacts activity. The objective of this study was to assess risk factors affecting fattening chicken mortality during transport to the laughterhouse, based on observations and analysis of a sample of 60 trucks with various destinations in the country. The average mortality rate in the study was 1.6 per 1000 chickens, whose highest impact variables on mortality during transport were the boarding temperature, causing a 3.4% increase in mortality per 1oC in temperature compared to base mortality; and, the age of the chickens at the time of shipment that caused a 17% increase in mortality for each additional day of stay on the farm, relative to the base mortality rate. In conclusion, mortality during fishing was increased in older broiler chickens, as well as by decreased temperature at the time of shipment. These identified risk factors can be used to refine management practices to mitigate some of the risk of fattening chicken mortality during transportation.Millones de pollos de engorde son transportados anualmente desde las granjas hasta las plantas de faenamiento. En este trayecto, los pollos están expuestos a una amplia variedad de factores estresantes como la restricción de alimento, la captura y el transporte que afectan el bienestar animal y producen pérdidas de peso vivo hasta la muerte, lo cual impacta económicamente la actividad. El objetivo del presente estudio fue evaluar los factores de riesgo que afectan la mortalidad de pollos de engorde durante su transporte a la planta de faenamiento, a partir de observaciones y análisis de una muestra de 60 camiones con varios destinos del país. La incidencia de mortalidad promedio en el estudio fue de 1,6 por cada 1.000 pollos, cuyas variables de mayor impacto sobre la mortalidad durante el transporte fueron, la temperatura de embarque al causar un incremento del 3,4% de mortalidad por cada 1 °C de descenso en la temperatura respecto de la mortalidad base; y, la edad de los pollos al momento de embarque que causó un incremento de 17% en la mortalidad por cada día adicional de estancia en finca, en relación con la tasa de mortalidad base. En conclusión, la mortalidad durante el faenado se incrementó en los pollos de engorde de mayor edad, así como por la disminución de la temperatura al momento del embarque. Estos factores de riesgo identificados pueden utilizarse para perfeccionar las prácticas de gestión a fin de mitigar parte del riesgo de mortalidad de pollos de engorde durante la transportación

Distribution and potential indicators of hospitalized cases of neurocysticercosis and epilepsy in Ecuador from 1996 to 2008

Background : Epilepsy is one of the most common signs of Neurocysticercosis (NCC). In this study, spatial and temporal variations in the incidence of hospitalized cases (IHC) of epilepsy and NCC in Ecuadorian municipalities were analyzed. Additionally, potential socio-economic and landscape indicators were evaluated in order to understand in part the macro-epidemiology of the Taenia solium taeniasis/cysticercosis complex. Methodology : Data on the number of hospitalized epilepsy and NCC cases by municipality of residence were obtained from morbidity-hospital systems in Ecuador. SatScan software was used to determine whether variations in the IHC of epilepsy and NCC in space and time. In addition, several socio-economic and landscape variables at municipality level were used to study factors intervening in the macro-epidemiology of these diseases. Negative Binomial regression models through stepwise selection and Bayesian Model Averaging (BMA) were used to explain the variations in the IHC of epilepsy and NCC. Principal findings : Different clusters were identified through space and time. Traditional endemic zones for NCC and epilepsy, recognized in other studies were confirmed in our study. However, for both disorders more recent clusters were identified. Among municipalities, an increasing tendency for IHC of epilepsy, and a decreasing tendency for the IHC of NCC were observed over time. In contrast, within municipalities a positive linear relationship between both disorders was found. An increase in the implementation of systems for eliminating excrements would help to reduce the IHC of epilepsy by 1.00% (IC95%; 0.2%-1.8%) and by 5.12% (IC95%; 3.63%-6.59%) for the IHC of NCC. The presence of pig production was related to IHC of NCC. Conclusion/Significance : Both disorders were related to the lack of an efficient system for eliminating excrements. Given the appearance of recent epilepsy clusters, these locations should be studied in depth to discriminate epilepsies due to NCC from epilepsies due to other causes. Field studies are needed to evaluate the true prevalence of cysticercosis in humans and pigs in different zones of the country in order to better implement and manage prevention and/or control campaigns

Intervalos de corte de pasto Saboya (Panicum máximum Jacq.), sobre rendimiento de materia seca y composición química de su ensilaje

During the dry season in the north of the Ecuadorian coast, there is a grass shortage, aspect that need to be solved. The objective of this research was to evaluate the effect of different cutting intervals on the dry biomass yield, chemical composition and nutritional quality of savoy grass (Panicum maximum Jacq.). During the rainy season transition to dry, in the Viche locality, in the province of Esmeraldas in Ecuador, the dry biomass, organoleptic characteristics, chemical and cell wall composition of savory grass silage cut at ages of 13, 20, 27, 34 and 41 days were evaluated. Treatments were set up in a Complete Random Design for the pasture characteristics and chemical composition of the silage, and in a Randomized Complete Block Design for the organoleptic characteristics of the silage. The statistical analysis was based on the Analysis of Variance and the multiple mean comparisons between treatments with Tukey at 5 %. In this research, the quality of silage organoleptic characteristics was higher at 20 and 34 days. Bromatological analyses showed a content of 8.25 % of crude protein at 27-day silage preparation, being the highest of all treatments, followed by silage preparation at 41-day with 5.53 % of crude protein. The annual dry matter yield ranged from 9.74 to 29.98 t ha-1. Silage prepared at 27 days had the highest nutritional values, while yield was higher at 41 days. None of the treatments reached an optimal level of fermentation (pH, lignification, stem/leaf ratio).Durante la época seca en el norte del litoral ecuatoriano, se presenta escasez de pasto aspecto que requiere resolverse. El objetivo de la presente investigación fue evaluar el efecto de diferentes intervalos de corte sobre el rendimiento de biomasa seca, composición química y calidad nutricional de ensilaje del pasto saboya (Panicum máximum Jacq.). Durante la transición de época lluviosa a seca, en la parroquia Viche de la provincia de Esmeraldas en Ecuador, se evaluó la biomasa seca, características organolépticas, composición química y de las paredes celulares del ensilaje de pasto Saboya cortado a edades de 13, 20, 27, 34 y 41 días. Los tratamientos se implementaron en un Diseño Completamente al Azar para las características del pasto y composición química del ensilaje, y en un diseño de Bloques Completos al Azar para las características organolépticas del ensilaje. El análisis estadístico se basó en el Análisis de Varianza y comparación múltiple de medias entre tratamientos usando Tukey al 5 %. En la investigación se determinó que las características organolépticas de los ensilajes a los 20 y 34 días fueron de mejor calidad. En el análisis bromatológico se determinó que el ensilaje a los 27 días contiene una media de 8,25 % de proteína bruta, que es estadísticamente mayor que todos los tratamientos evaluados, seguido por el ensilaje a los 41 días con 5,53 % de proteína bruta. El rendimiento de materia seca anual varió de 9,74 a 29,98 t ha-1. El ensilaje preparado a los 27 días presentó los mejores valores nutricionales, mientras que el mejor rendimiento se presentó a los 41 días. Ningún tratamiento alcanzó un nivel óptimo de fermentación (pH, lignificación relación tallo/hoja)

Efecto de la labranza y fertilización nitrogenada en los cultivos de fréjol y maíz sobre indicadores biológicos de la calidad de un suelo andino del Ecuador

Biological parameters are used as early indicators of the quality of an agricultural soil (ICS), due to their quick response to the anthropic soil management. The main objective of this research was to determine the effect of the tillage system: no-till (SD) and conventional tillage (LC), and to the nitrogen fertilization in bean and corn crop on certain biological indicators of soil quality. The study was carried out on a mollisol from the Andean region of Ecuador. Microbial biomass (MB), microbial respiration (RM), and enzyme activity (acid phosphatase, hydrolysis of fluorescein diacetate [FDA], and β-glucosidase [β-G]) were determined. The results showed that the phosphatase presented the highest activity under LC, the FDA responded to the effect of high nitrogen levels application (N), the activity of the β-G enzyme was higher under LC. Additionally, the principal component analysis selected these biological indicators studied as ICS. It is concluded that the biological indicators of the soil were affected by the management practices studied.Los parámetros biológicos son usados como indicadores tempranos en la calidad de un suelo (ICS) agrícola, ya que responden rápidamente al manejo antrópico. El objetivo de esta investigación fue determinar el efecto del sistema de labranza: siembra directa (SD) y labranza convencional (LC), y de la fertilización nitrogenada después de los cultivos de fréjol y maíz, sobre ciertos indicadores biológicos de la calidad del suelo. El estudio se realizó sobre un molisol de la región andina del Ecuador. Se determinó la biomasa microbiana (BM), respiración microbiana (RM), y actividad enzimática (fosfatasa ácida, hidrólisis de la fluoresceína-diacetato [FDA], y β-glucosidasa [β-G]). Los resultados mostraron que la fosfatasa presentó la mayor actividad bajo LC, la FDA respondió al efecto de los niveles altos de nitrógeno (N), la actividad de la enzima β-G fue mayor en LC. Adicionalmente, el análisis de componentes principales seleccionó a los indicadores biológicos estudiados, como ICS. Se concluye que los indicadores biológicos del suelo fueron afectados por las prácticas de manejo estudiadas

The Associated Decision and Management Factors on Cattle Tick Level of Infestation in Two Tropical Areas of Ecuador.

peer reviewedDecision-making on tick control practices is linked to the level of knowledge about livestock farming and to the social context in which individuals practice them. Tick infestation is one of the main problems in tropical livestock production. The objective of this study was to characterize tick-control related practices in two tropical livestock areas and their potential association with the level of tick infestation. A total of 139 farms were included in this survey. To determine this association, a multivariate logistic regression model was used. A stepwise model selection procedure was used and model validation was tested. Cattle husbandry as a main activity, the use of external paddocks, the use of amitraz, and the lack of mechanization on the farm were related with high tick infestation. On the other hand, owner involvement in the preparation of acaricide solution was identified as a protective factor against high tick infestation. At animal level, age (old), body condition status (thin), and lactation were also associated with high tick infestations, while Bos primigenius indicus cattle and their crosses reduced the probability of high tick infestations. The factors studied, such as herd size, education level of the owners, and veterinary guidance, varied from farm to farm. Nonetheless, these differences did not generate changes in the level of tick infestation. According to the area under the receiver operating characteristic curve (AUC-ROC), the model at farm level predicts a high level of infestation, with an accuracy of 72.00% and high sensitivity. In addition, at animal level, crossbreeding with indicus cattle and breeding selection for host resistance will be useful against high tick infestation. Likewise, the implementation of programs of capacitation and research on tick control for farmers, cowboys, and vets in these areas is necessary

Grado de infestación de garrapatas asociado con factores individuales del ganado bovino en ganaderías subtropicales del Ecuador

En Ecuador, Rhipicephalus microplus es la principal garrapata que afecta al ganado bovino, cuyo control exige conocer su comportamiento. El objetivo de este estudio fue evaluar el grado de infestación de R. microplus, examinando la ubicación anatómica de las garrapatas y su posible asociación con factores intrínsecos de los animales como son el estado general de salud, condición corporal, color del pelaje. Se llevaron a cabo cuatro muestreos cada tres meses en un total de 15 fincas en el Noroccidente de Pichincha (localidad1) y 15 fincas en el Valle de los Quijos (localidad2). Las garrapatas mayores a 0.5cm fueron contadas en 5 animales escogidos al azar. Como resultados, en cuatro muestreos realizados en las dos localidades, se encontró un promedio de 99.39 ± SD156.28(0–1426) garrapatas por animal, y un promedio de 108.8±SD179.43(0–1426) y 88.2 ± SD122.80(0–824) para la localidad 1 y 2, respectivamente. Solo la variable "salud aparente de piel y pelaje" mostró una asociación estadística positiva, con un valor P<0.05 y odds ratios de 5.13(IC 95%: 2.04-13.65) y 25.83(IC 95%: 7.63-109.39) en las categorías "regular" y "malo" respecto del estado considerado como bueno. Además, la categoría animal denominado "viejo" en la variable Edad tuvo un valor P=0.05 y un odds ratio de 2.88(IC 95%: 1.04-8.80). Anatómicamente se encontraron más garrapatas en la zona anatómica correspondiente a muslos, ubre posterior, pierna y corvejón, con un promedio de 38.52±SD70.17(0–448) garrapatas. En conclusión, la infestación con garrapatas representa un problema grave que afecta a las ganaderías de regiones tropicales del país, este estudio ayuda a direccionar de mejor manera las formas y prácticas de control sobre los bovinos

An economic evaluation of cattle tick acaricide-resistances and the financial losses in subtropical dairy farms of Ecuador: A farm system approach.

peer reviewedEstimates of economic losses in cattle due to tick infestations in subtropical areas are limited, such as in Ecuador. Ticks affect animal production and health, but those direct effects are difficult to estimate since financial exercises carried out in farms consider both costs of the inputs and revenues. This study aims to quantify the costs of inputs involved in milk production and to know the role of acaricide treatment in the production costs on dairy farms in subtropical zones using a farming system approach. Regression and classification trees were used to study the relationship between tick control, acaricide resistance and the presence of high level of tick infestation in the farm system. Even though there was no significant direct association between high levels of tick infestation and the presence of acaricide resistance in ticks, a more complex structure for resistances operates in the manifestation of high tick infestation involving levels of farm technology and no acaricide resistance. Farms with higher levels of technology allocate a lower percentage of sanitary expenses to control ticks (13.41%) in comparison to semi-technified (23.97%) and non-technified farms (32.49%). Likewise, more technified and bigger herds have a lower annual expenditure on acaricide treatment (1.30% of the production budget equivalent to 8.46 USD per animal) compared to non-technified farms where it can represent more than 2.74% of the production budget and where the absence of cypermethrin resistance increases the treatment cost to 19.50 USS per animal annually. These results can motivate the development of information campaigns and control programmes targeted to the reality of small and medium farms that are the most affected in terms of the money they invest in controlling ticks