Abstract The objective of the study was to evaluate the effect of different levels of maize silage on feed utilization efficiency and nitrogen (N) balance in dual-purpose cows during the dry season. Nine crossbred cows with live weight of 423±12 kg were used. The treatments were: T1= 2 kg DM of maize silage + 3.9 kg DM of sorghum stubble; T2= 4 kg DM of maize silage + 1.8 kg DM of sorghum stubble; T3= 6 kg DM of maize silage. Additionally, all cows consumed Panicum maximum cv. Mombasa grass, supplemented with poultry manure and commercial concentrate in doses of 2.0, 2.9 and 2.3 kg DM, respectively. Data comparison was performed by ANOVA, and the experiment was conducted using a completely randomised mathematical model with three replicates. No significant differences (p >0.05) were observed for any of the variables evaluated. N intake reached 279.8 g day-1 of which 8.5% was excreted in milk, 42.1% in faeces and 41.2% in urine. Milk production was 4.4 kg cow-1 day-1, with 33.1 g kg-1 fat and 34.4 g kg-1 crude protein (CP). N balance was 27.5 g cow-1 day-1, while utilization efficiency reached 8.6%. A higher inclusion of maize silage increased CP and N contents of the diet supplied to the cows, but it did not result in higher milk production. Feed utilization efficiency was limited even in the treatment with the lowest N content in the ration (T1). Further research is required to evaluate the economic and productive viability of the dietary inclusion of different silages, as a feeding strategy to cope with the low availability of forages during dry periods in low-scale milk production systems.

Resumen El objetivo del trabajo fue tipificar unidades productivas de doble propósito y caracterizar los recursos para la producción de forrajes y los problemas que afectan a la ganadería en Sinaloa, México. Mediante muestreo no probabilístico se seleccionaron 61 ranchos de ocho municipios del estado de Sinaloa, a través de análisis factorial y análisis clúster fueron identificados cuatro grupos de productores: E1, E2, E3 y E4. Los productores tienen diversos usos de la tierra para la producción de forrajes: siembra de cultivos anuales, praderas, pastoreo en tierras en descanso y uso del agostadero. La sequía es el principal problema para el 52.5 % de los productores. Los productores que cuentan con mayor tamaño de hato (E3 y E4) tienen mayor superficie agrícola y agostadero; sin embargo, presentan una mayor vulnerabilidad en sus sistemas de producción, por lo que tienen que recurrir a la compra de forrajes. El 86.7 % de los productores señaló que el hato ha disminuido por el problema de la sequía, por lo que se requiere del desarrollo de estrategias tecnológicas y políticas para mejorar la producción de forrajes bajo el contexto de cambio climático, y así disminuir la presión y posible deterioro de la superficie agrícola y el agostadero en la región de estudio.

Abstract The objective of the work was to typify dual-purpose production units and characterize the resources for fodder production and the issues affecting livestock production in Sinaloa, Mexico. Through non-probabilistic sampling, 61 ranches were selected from eight municipalities in the state of Sinaloa, and four groups of producers were identified through factor analysis and cluster analysis: E1, E2, E3, and E4. Producers have diverse land uses for fodder production: planting of annual crops, pastures, grazing on fallow land, and use of pasture lands. Drought is the main issue for 52.5 % of the producers. Producers with larger herd sizes (E3 and E4) have more agricultural and grazing land; however, their production systems are more vulnerable and, therefore, they have to resort to the purchase of forage. 86.7 % of the producers pointed out that the herd has decreased due to the problem of drought, which requires the development of technological strategies and policies to improve forage production within the context of climate change, and thus reduce the pressure and potential deterioration of agricultural and pasture land in the study region.

Resumen La Leucosis Enzoótica Bovina (LEB) es una enfermedad viral que afecta a bovinos y presenta una distribución mundial, con prevalencias de 13.5-54.6 % a nivel nacional. Su sintomatología puede ser imperceptible en un principio, pero con el tiempo se manifiesta de diferentes maneras dependiendo del órgano afectado. El mecanismo de replicación hace que el virus sea prácticamente imposible de tratar, afectando los linfocitos B y los monocitos, lo que predispone al ganado a la incidencia de agentes patógenos oportunistas y hace que cualquier tipo de secreción y excreción se convierta en un probable factor de contagio. El objetivo de este estudio fue determinar la seroprevalencia de LEB y algunos factores de riesgo en bovinos del trópico alto de Boyacá, Colombia. Se tomaron muestras serológicas de 385 ejemplares bovinos, las cuales fueron procesadas utilizando el kit comercial SERELISA BLV Ab Mono Blocking. Se determinó la prevalencia mediante el programa estadístico Epi Info y se establecieron los factores determinantes, calculando la razón de prevalencia para identificar factores de riesgo. Se encontró una prevalencia aparente (PA) del 19.72 %. Las hembras fueron más seropositivas (19.94 %) que los machos (14.29 %), y el grupo etario de 2 a 4 años presentó la mayor seropositividad de anticuerpos contra e virus LEB (21.21%), seguido de los individuos mayores de 4 años (20.63 %) y los animales menores de 2 años (16.6%). Por otra parte, la raza Normando fue la menos seropositiva (17.4%), mientras que los cruces raciales tuvieron mayor seroprevalencia (22.22%). Aunque no se identificó ninguna variable como factor de riesgo, es crucial prestar atención a aquellas que presentaron una asociación estadística significativa, pueden influir en la transmisión del virus.

Abstract Enzootic Bovine Leukosis (EBL) is a viral disease that affects cattle and has a worldwide distribution, with national prevalences of 13.5-54.6%. Its symptoms can be imperceptible at first, but they manifest in different ways over time depending on the affected organ. The replication mechanism makes the virus virtually impossible to treat, affecting B lymphocytes and monocytes, which predisposes cattle to the incidence of opportunistic pathogenic agents and turns any type of secretion and excretion into a probable contagion factor. The aim of this study was to determine the seroprevalence of EBL and some risk factors in cattle from the high tropic of Boyacá, Colombia. Serological samples from 385 bovine specimens were taken, which were processed using the commercial SERELISA BLV Ab Mono Blocking kit. Prevalence was determined using the Epi Info statistical software, and determining factors were established, calculating the prevalence ratio to identify risk factors. An apparent prevalence (AP) of 19.72% was found. Females were more seropositive (19.94%) than males (14.29%), and the age group from two to four years showed the highest seropositivity for antibodies against the EBL virus (21.21%), followed by individuals aged more than four (20.63%) and animals under two years old (16.6%). Moreover, the Normande breed was the least seropositive (17.4%), while crossbreeds had a higher seroprevalence (22.22%). Although no variable was identified as a risk factor, it is crucial to pay attention to those that showed a significant statistical association, as they may influence the transmission of the virus.

Resumo A Leucose Enzoótica Bovina (LEB) é uma doença viral que afeta bovinos e possui ampla distribuição mundial com prevalência de 13,5% a 54,6% a nível nacional. A sua sintomatología pode ser imperceptível no início, mas com o passar do tempo manifesta-se de diferentes formas, dependendo do órgão afetado. O mecanismo de replicação torna o vírus praticamente impossível de tratar, afetando linfócitos B e monócitos, o que predispõe à incidência de patógenos oportunistas e torna qualquer tipo de secreção e excreção como provável fator de contágio. O objetivo deste estudo foi determinar a soroprevalência da LEB e alguns fatores de risco em bovinos do Alto Trópico de Boyacá-Colômbia. Amostras sorológicas 385 bovinos foram coletadas. As todas as amostras foram processadas com o kit comercial SERELISA® BLV Ab Mono Blocking (Zoetis, Estados Unidos). A prevalência foi estimada utilizando o programa estatístico Epi Info® e os fatores determinantes foram estabelecidos, calculando-se a razão de prevalência para identificar os fatores de risco. Foi encontrada uma prevalência aparente (PA) de 19,72%. As fêmeas foram mais soropositivas (19,94%) que os machos (14,29%), sendo que a faixa etária de 2 a 4 anos apresentou a maior soropositividade de anticorpos contra o vírus da LEB (21,21%), seguida dos individuos >4 años (20,63%) e os animais <2 anos (16,6%). Do mesmo modo, a raça Normanda foi a menos soropositiva (17,4%) enquanto a mestiça teve a maior soroprevalência (22,22%). Embora nenhuma variável tenha sido estabelecida como fator de risco, é fundamental considerar às variáveis que apresentaram associação estatística significativa, pois podem influenciar na transmissão do vírus.

Abstract Guinea pigs in intensive production generates an imperative necessity of physio-pathological bases for diagnosing their state of welfare, health, and production; those which are available for this species are referred to as laboratory or companion animal. The aim of this research is to determine changes in hematological and blood metabolites profiles in relation to age of Cavia porcellus reared in intensive system at 660 masl in humid tropic. For this purpose, forty 15-120 days old guinea pig in healthy conditions from the inti x Peru lines born in the humid tropic were used and the evaluation ages were 15-21, 22-35, 36-60 and 61-120 days. Blood samples were obtained by puncture of the cephalic vein; profiles of erythrocytes (RBC), total leucocytes (WBC), lymphocytes, granulocytes, hematocrit, hemoglobin, MCV, MCH and MCHC indices were determined. In serum, profiles of glucose, total protein (TP), albumin, total cholesterol (TC), triglycerides, total bilirubin (TB), and direct bilirubin (DB), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined. Hemoglobin profile, MCH and MCHC indices increased as age increased (p < 0,05) and the erythrocytes, leucocytes, hematocrit, hemoglobin profiles and MCV, MCH, MCHC indices showed the narrower interval ranges in the 15-35and 61-120-days old guinea pigs. Profiles of TP, DB and AST showed increase with age (p < 0,05) and the DB, AST, ALT, and TC profiles showed the narrower interval range at 36-120 days old. The hematological and blood metabolites profiles of guinea pigs raised in intensive system in humid tropical conditions show significant changes with production age.

Resumen Los cuyes en producción intensiva generan la necesidad de bases fisiopatológicas para diagnosticar su estado de bienestar, salud y producción; las disponibles están referidas a esta especie como animal de laboratorio o de compañía. El objetivo de esta investigación es determinar los perfiles hematológicos y metabolitos sanguíneos en relación con la etapa de producción de cuyes en sistema de crianza intensivo a 660 msnm en trópico húmedo. Cuarenta cuyes clínicamente sanos de las líneas inti x Perú nacidos en trópico de 15-120 días de edad se distribuyeron en cuatro grupos etarios: 15-21, 22-35, 36-60 y 60-120 días. En sangre se determinó los perfiles de eritrocitos, leucocitos, linfocitos, granulocitos, hematocrito y hemoglobina e índices de MCV, MCH y MCHC y en suero sanguíneo los perfiles de glucosa, proteína total (PT), albumina, colesterol total (CT), triglicéridos, ALT, AST y bilirrubina directa (BD). El perfil de hemoglobina y los índices de MCH y MCHC incrementaron con la edad (p < 0, 05) y los perfiles de eritrocitos, leucocitos, hemoglobina y hematocrito y los índices de MCV, MCH, MCHC mostraron una menor amplitud de intervalos en los cuyes de 15-35 y 61-120 días de edad. Los perfiles de PT, BD y AST incrementaron con la edad (p < 0, 05) y los perfiles de BD, AST, ALT y CT mostraron la menor amplitud de intervalo entre los 36-120 días de edad. Los perfiles hematológicos y de metabolitos sanguíneos en los cuyes criados en sistema de crianza intensivo en condiciones de trópico húmedos muestran cambios significativos con la edad de producción.

ABSTRACT In the tropic, many crops are distributed in the highlands of provinces of the Andean regions at heights of 2,500 m asl and constitute the areas with the highest susceptibility to the frost events occurrence. The study objective was to propose an early frost prediction model based on the relationships between frost events and climatic variables, modeled with machine learning methods. The climatic variables were obtained from thirteen meteorological stations located inside flower crops and distributed in nine municipalities of the Cundinamarca Department. The variables registered were temperature, relative humidity, dew point, photosynthetically active radiation, and precipitation, entered as explanatory variables of frost events. The metrics used for predictive performance evaluation of the five machine learning methods examined were precision, recall, true negative rate, accuracy, and F1 score. The variables’ climatic behavior of previous hours to a frost event are low humidity, wind speed and cloudiness, and high thermal radiation. The fourth of the five trained models performed well due to their classification evaluation metrics, greater than 91%. The cross-validation and statistical analysis demonstrated the higher accuracy of the GBDT model on frost events detection. tropic 2500 2 500 2,50 occurrence Department temperature humidity point radiation precipitation precision recall rate F score cloudiness 91 91% crossvalidation cross validation detection 250 50 2,5 9 25 5 2,

Resumo: A produção colombiana de abacate Hass tem sido ameaçada pelas chuvas altas e constantes registradas nos últimos anos, o que tem causado restrições no crescimento das raízes, reduções de rendimento e até, em alguns casos, a morte das árvores. O objetivo deste estudo foi avaliar a relação entre o crescimento da raiz em abacateiros Hass e o efeito de algumas variáveis físicas do solo no trópico andino colombiano. As avaliações foram realizadas em duas plantações comerciais de abacate Hass com 5 anos de idade, com árvores enxertadas em porta-enxertos de sementes nativas. Para avaliar o crescimento das raízes, foram realizadas extrações mensais de raízes em cada pomar. Além disso, foram realizados testes de infiltração nas zonas de gotejamento das árvores e nos caminhos de cultivo de cada zona. Além disso, foi realizadauma classificação laboratorial da areia para determinar a proporção em função do tamanho. Foram observadas diferenças estatísticas no crescimento da raiz, nos dois pomares. No entanto,não houve diferenças estatísticas nas taxas de infiltração na copa/caminho ounas taxas de infiltração por pomar. O crescimento da raiz foi restrito em solos com menor infiltração e maior proporção de areias finas. Resumo até casos colombiano idade portaenxertos porta enxertos nativas pomar disso zona tamanho pomares entantonão entanto não copacaminho copa caminho finas

Abstract: The production of Hass avocados in Colombia has been increasingly threatened by the high and persistent rainfall observed in recent years, which has led to restrictions in root growth, yield reductions, and, in some cases, tree mortality. This study aimed to evaluate the relationship between root growth in Hass avocado trees and the influence of certain soil physical variables in the Colombian Andean tropic. The evaluations were conducted in two commercial 5-year-old Hass avocado plantations, with trees grafted onto rootstocks derived from native seeds. Root growth was assessed through monthly root extractions in each orchard. Additionally, infiltration tests were performed in the drip zones of the trees and along the cultivation paths in each area. Furthermore, laboratory analysis of sand grading was conducted to determine the particle size distribution. Statistical differences in root growth were observed between the two orchards. However, no significant differences were found in drip zone and path infiltration rates or between the overall infiltration rates of the orchards. Root growth was restricted in soils with lower infiltration rates and higher proportion of fine sands. Abstract years reductions cases mortality tropic 5yearold yearold 5 year old plantations seeds orchard Additionally area Furthermore distribution orchards However sands

Abstract Traditional peach production regions provide adequate chill for satisfactorily bud’s flower break dormancy, in cultivars there developed. However, considering the expansion of the orchards in mild winter areas and the expected global trends to warmer conditions, the local development of cultivars became relevant. Based on this background, this study proposed to evaluate the performance of 33 peach and nectarine cultivars and selections in mild winter climate. Features associated to the vegetative development, phenology, productivity and fruit characteristics were measured in nine seasons, and the data analyzed by multivariate analysis of variance. Significant correlations between features were remarked. The Pillai and F tests presented significant results, highlighting significant differences among cultivars for almost all features. Peach and nectarine genotypes showed genetic diversity that may be accessed for use as cultivars, or parental for crosses. ‘IAC Aurora 1’, ‘IAC Aurora 2’, ‘IAC Centenário’, ‘IAC Douradão’, ‘IAC Jóia4’, ‘IAC Ouromel 3’, ‘IAC Régis’, ‘Diamante’, ‘Eldorado’, ‘FlordaPrince’, ‘Premier’ and ‘Tropic Beauty’ were the cultivars with the best results. A large number of selections showed promising results, emphasizing, the ‘IAC 680-177’, ‘IAC 1085-27’, ‘IAC 785-9’, ‘IAC 2982-31’, ‘IAC 4682-45’and ‘IAC 6882-84’. buds bud s dormancy developed However conditions relevant background 3 climate phenology seasons variance remarked results crosses IAC 1, 1 , 1’ 2, 2 2’ Centenário, Centenário Centenário’ Douradão, Douradão Douradão’ Jóia4, Jóia4 Jóia Jóia4’ 3, 3’ Régis, Régis Régis’ ‘Diamante, Diamante ‘Diamante ‘Diamante’ ‘Eldorado, Eldorado ‘Eldorado ‘Eldorado’ ‘FlordaPrince, FlordaPrince ‘FlordaPrince ‘FlordaPrince’ ‘Premier Premier Tropic Beauty emphasizing 680177, 680177 680 177 680-177’ 108527, 108527 1085 27 1085-27’ 7859, 7859 785 9 785-9’ 298231, 298231 2982 31 2982-31’ 468245and 4682 45 688284. 688284 6882 84 . 6882-84’ 68017 68 17 680-177 10852 108 1085-27 78 785-9 29823 298 2982-31 468 4 68828 688 8 6882-84 6801 6 680-17 10 1085-2 7 785- 29 2982-3 46 6882-8 680-1 1085- 2982- 6882- 680-

Resumo As regiões tradicionais de produção de pêssego apresentam frio adequado para a quebra de dormência das gemas de forma satisfatória, nas cultivares localmente desenvolvidas. No entanto, considerando a expansão dos pomares em áreas peachde inverno ameno e as tendências globais esperadas para condições mais quentes, o desenvolvimento local de cultivares tornou-se relevante. Com base nisso, este estudo propôs-se a avaliar o desempenho de 33 cultivares e seleções de pessegueiro e nectarineiraem clima de inverno ameno. Características associadas ao desenvolvimento vegetativo,fenologia, produtividade e características dos frutos foram medidas em nove safras; e os dados, analisados por análise de variância multivariada. Foram observadas correlaçõessignificativas entre as características. Os testes de Pillai e F apresentaram resultadossignificativos, destacando a presença de diferenças entre cultivares para quase todas as características.Os genótipos de pessegueiro e de nectarineira apresentaram diversidade genética que pode ser acessada para uso como cultivares, ou parentais para cruzamentos. As cultivares ‘IACAurora 1’, ‘IAC Aurora 2’, ‘IAC Centenário’, ‘IAC Douradão’, ‘IAC Jóia4’, ‘IACOuromel 3’, ‘IAC Régis’,‘Diamante’, ‘Eldorado’, ‘FlordaPrince’, ‘Premier’ e ‘Tropic Beauty’apresentaram os melhores resultados. Um grande número de seleções apresentou resultados promissores, destacando-`se ‘IAC 680-177’, ‘IAC 1085-27’, ‘IAC 785-9’, ‘IAC 2982-31’, ‘IAC 4682-45’ e‘IAC 6882-84’. satisfatória desenvolvidas entanto quentes tornouse tornou se relevante nisso propôsse propôs 3 vegetativofenologia vegetativo fenologia vegetativo,fenologia safras dados multivariada resultadossignificativos característicasOs cruzamentos IACAurora 1, 1 , 1’ IAC 2, 2 2’ Centenário, Centenário Centenário’ Douradão, Douradão Douradão’ Jóia4, Jóia4 Jóia Jóia4’ IACOuromel 3, 3’ Régis,‘Diamante, RégisDiamante Régis ,‘Diamante Diamante Régis’,‘Diamante’ ‘Eldorado, Eldorado ‘Eldorado ‘Eldorado’ ‘FlordaPrince, FlordaPrince ‘FlordaPrince ‘FlordaPrince’ ‘Premier Premier Tropic Beautyapresentaram Beauty promissores destacando`se destacandose `se 680177, 680177 680 177 680-177’ 108527, 108527 1085 27 1085-27’ 7859, 7859 785 9 785-9’ 298231, 298231 2982 31 2982-31’ 468245 4682 45 4682-45 eIAC 688284. 688284 6882 84 . 6882-84’ Régis,‘Diamante Régis’,‘Diamante 68017 68 17 680-177 10852 108 1085-27 78 785-9 29823 298 2982-31 46824 468 4 4682-4 68828 688 8 6882-84 6801 6 680-17 10 1085-2 7 785- 29 2982-3 46 4682- 6882-8 680-1 1085- 2982- 6882- 680-

RESUMEN El manejo activo de los pastos incide en la productividad animal y en los procesos biogeoquímicos del suelo, el ciclaje de nutriente, donde la gestión de los pastos es un factor relevante para mantener estos procesos biogeoquímicos, productividad y el flujo de emisiones de gases de efecto invernadero (GEI). El objetivo principal del presente estudio fue evaluar las emisiones de GEI provenientes de tres tipos de fertilizantes (convencional, urea+inhibidor y biofertilizante) empleados para el mantenimiento de pasturas en la producción lechera en el trópico húmedo de Costa Rica, con el fin de identificar medidas de mitigación que contribuyan a la reducción de emisiones de GEI en el sector agropecuario y a la Contribución Nacionalmente Determinada (CND) de Costa Rica. El diseño experimental correspondió a un diseño en bloques completamente aleatorizado, donde con tres repeticiones por tratamiento (control, biofertilizante, urea+inhibidor y fertilizante convencional), el total de muestras correspondió a 497 muestras, durando el periodo de 81 días. La medición de las cantidades de metano (CH4), óxido nitroso (N2O) y el análisis de contenido de carbono y nitrógeno se realizó a una profundidad de -10 cm para tomar la muestra de suelo y ser analizadas mediante un método instrumental de oxidación seca. Los promedios de estas mediciones fueron: 0,104 mgN2O-N/m2/día y 0,037 mgCH4-C/m2/día. Las emisiones de los GEI durante el monitoreo estuvieron influenciadas por procesos de metanogénesis, desnitrificación, nitrificación y respiración. Además, el biofertilizante (biol) fue el fertilizante que presentó las menores emisiones de GEI considerando también las concentraciones de Carbono y Nitrógeno en el suelo.

ABSTRACT The active management of pastures affects animal productivity and soil biogeochemical processes of the soil, nutrient cycling, where pastures management is a relevant factor to maintain these biogeochemical processes, productivity, and the flow of Greenhouse Gas emissions. Greenhouse (GHG). The main objective of this study was to evaluate the GHG emissions from three types of fertilizers (conventional, urea and biofertilizer) used for the maintenance of pastures in dairy production in the humid tropics of Costa Rica, in order to identify measures of mitigation that contribute to the reduction of GHG emissions in the agricultural sector and that contribute to the NDC of the country. The experimental design corresponds to a completely randomized block design, where with three repetitions per treatment (Control, Biofertilizer, Urea and Conventional Fertilizer), the total of samples corresponds to 497 samples, during a period of 81 days. Measurement of the amounts of methane (CH4) and nitrous oxide (N2O). The analysis of the Carbon and Nitrogen content was performed at a depth of -10 cm to take the soil sample and analyze it by means of an instrumental method of dry oxidation. The mean values of these measurements were as follows: 0,104 mgN2O-N/ m2/day and 0,037 mgCH4-C/m2/day. GHG emissions during monitoring were influenced by processes of methanogenesis, denitrification, nitrification and respiration. The biofertilizer (biol) presented the lowest GHG emissions given considering the concentrations of Carbon and Nitrogen in the soil.

Abstract Few studies reflect the hydrodynamic behavior of surface flows on slopes of the tropics, despite the number of modeling tools currently available. The present investigation is a contribution that helps to increase the knowledge of the dynamics of the runoff on the slopes, as an extra study of the behavior of the precipitations on these. The analyzes carried out take relevance within the basic studies of a project, developing within the disciplines of hydrodynamics, geology and environment. The case studied is found on a slope in the Cervantes sector, which has already been intervened with a double-reinforced steel mesh as a superficial erosive control. With the research, a comparison of applied works and a new sustainable proposal are made using bidimensional modeling tools. The models reflect the behavior of the flow velocities in general and specific due to the distribution on a slope, a comparison of their flow velocities was made in three scenarios, having a decrease of 33.73% to 48.88% in the flow velocities of the proposed coverage, both for events with a return period of 50 and 100 years. In addition, a climate change effect was analyzed, which verified that the flow speeds do not exceed the theoretical drag limits for the proposed model and in which case it was fully complied with. As runoff control, the proposed coverage fulfills its function. However, due to the particular conditions of the analized slope, the proposal works as a complement to the applied measures.

Resumen Pocos estudios reflejan los comportamientos hidrodinámicos de los flujos superficiales en taludes del trópico, a pesar de la cantidad de herramientas de modelación con las que se cuenta en la actualidad. La presente investigación es un aporte que ayuda a incrementar los conocimientos de la dinámica de las escorrentías en los taludes, como un estudio extra de los comportamientos de las precipitaciones sobre estos. Los análisis realizados toman relevancia dentro de los estudios básicos de un proyecto, desarrollándose dentro de las disciplinas de hidrodinámica, geología y ambiental. El caso estudiado se ubica en un talud del sector de Cervantes, el cual ya fue intervenido con una malla de acero de doble refuerzo como un control erosivo superficial. Con la investigación se realiza una comparativa de obras aplicadas y una nueva propuesta sostenible mediante herramientas de modelación bidimensional. Los modelos reflejan el comportamiento de las velocidades de flujo en general y puntual debido a la distribución en un talud, se realizó una comparación de sus velocidades de flujo en tres escenarios, teniendo una disminución de 33,73% hasta 48,88% en las velocidades de flujo de la cobertura propuesta, tanto para eventos de periodo de retorno de 50 y 100 años. Además se analizó un efecto de cambio climático, que verifica que las velocidades no superen los límites de arrastre teóricos de finos para el modelo propuesto y en cuyo caso se cumplió a cabalidad. Como control de escorrentía, la cobertura propuesta cumple su función, sin embargo por las condiciones particulares del talud analizado la propuesta se desempeña como un complemento de las medidas aplicadas.

RESUMEN Se evaluaron cuatro pastos tropicales, Maralfalfa (Pennisetum violaceum Lam), pasto Morado (P. purpureum x P. typhoides), Elefante (Pennisetum purpureum, Schumach) y Guatemala (Tripsacum laxum, Nash) con dos intervalos de corte (45 y 70 días), mediante un experimento factorial con diseño de bloques completos al azar. La interacción pastos × frecuencias de corte fue significativa (p<0.05) para las características agronómicas y nutricionales. Pasto Morado y Guatemala cosechados a los 70 días obtuvieron mayor rendimiento de materia seca (17.13 y 17.03 t ha-1, respectivamente) que Maralfalfa, Morado, Elefante y Guatemala cosechados a los 45 días. En comparación con otros pastos, el pasto Guatemala cosechado a los 45 días obtuvo la relación hoja: tallo más alta (4.64). Los mayores contenidos promedio de proteína (78.5 g kg-1) y fósforo (1.22 g kg-1) se obtuvieron a los 45 días. Se concluye que las gramíneas cosechadas a los 70 días demuestran su potencial productivo con un valor nutritivo moderado, lo que podría ser utilizado para incrementar el rendimiento por unidad de área. Además, el pasto Guatemala podría ser utilizado en estudios con animales en pastoreo debido a su alta relación hoja: tallo y valor nutritivo moderado.

ABSTRACT Four tropical grasses were evaluated: Maralfalfa (Pennisetum violaceum Lam), Purple King grass (P. purpureum x P. typhoides), Elephant grass (Pennisetum purpureum, Schumach) and Guatemala grass (Tripsacum laxum, Nash) with two harvest intervals (45 and 70 days), using a factorial experiment with a randomized complete block design. The interaction pastures × cutting frequencies was significant (p<0.05) for the agronomic and nutritional characteristics. Purple King Grass and Guatemala harvested at 70 days produced higher dry matter yield (17.13 and 17.03 t ha-1, respectively) than Maralfalfa, Purple King Grass, Elephant grass, and Guatemala grass harvested at 45 days. Compared with other grasses, the Guatemala grass harvested at 45 days had the highest leaf: stem ratio (4.64). The highest average contents of protein (78.5 g kg-1) and phosphorus (1.22 g kg-1) were obtained at 45 days. It is concluded that the grasses harvested at 70 days showed their productive potential with a moderate nutritional value, which could be used to increase the yield per unit area. In addition, Guatemala grass could be used in studies with grazing animals due to its high leaf: stem ratio and moderate nutritional value.

Resumo O Corredor Rodoviário Bioceânico (CRB) entre Brasil, Paraguai, Argentina e Chile é um projeto cujo principal objetivo é oferecer novas oportunidades de desenvolvimento para as regiões periféricas e sem litoral do Trópico de Capricórnio. No entanto, para que ocorra uma transformação regional, é necessário mais que construir infraestrutura. Em particular, é necessário uma coordenação eficaz entre os diferentes atores para alcançar o desenvolvimento. O principal objetivo deste documento é fornecer uma explicação detalhada sobre a estrutura da rede de atores do CRB, bem como propor uma abordagem de governança potencial que facilite uma melhor coordenação entre os participantes. Por meio de uma análise de redes sociais (ARS) exploramos a dinâmica de participação e tomada de decisão entre os diferentes atores envolvidos. Os resultados revelaram uma baixa participação do setor privado, poucos vínculos transnacionais (maiores interações entre atores de um mesmo país), baixa interação entre atores governamentais nacionais e subnacionais-locais, e pouco envolvimento do governo nacional na Argentina. Em relação à proposta de governança, sugere-se a criação de duas novas mesas (Desenvolvimento Socioambiental e Segurança Fronteiriça), a promoção de missões empresariais com visão de integração regional e a preservação dos avanços do Grupo de Trabalho CRB. CRB (CRB Brasil Paraguai Capricórnio entanto infraestrutura particular participantes ARS (ARS envolvidos privado maiores país, país , país) subnacionaislocais, subnacionaislocais subnacionais locais, locais subnacionais-locais sugerese sugere se Desenvolvimento Fronteiriça, Fronteiriça Fronteiriça)

Resumen El Corredor Vial Bioceánico (CVB) entre Brasil, Paraguay, Argentina y Chile es un proyecto cuyo principal objetivo es ofrecer nuevas oportunidades de desarrollo las regiones periféricas y sin acceso al mar del trópico de Capricornio. Sin embargo, la transformación regional necesita algo más que la construcción de infraestructura. Particularmente requiere una coordinación efectiva entre distintos actores para alcanzar el desarrollo. El objetivo principal de este artículo es proporcionar una explicación detallada sobre la estructura de la red de actores del CVB, así como proponer un enfoque potencial de gobernanza que facilite una mejor coordinación entre los participantes. A través de un análisis de redes sociales (Social Network Analysis [SNA]) hicimos una exploración de las dinámicas de participación y toma de decisiones entre los diferentes actores involucrados. Los principales hallazgos muestran una baja participación del sector privado, pocos vínculos transnacionales (mayores interacciones entre actores del mismo país), pocos vínculos entre actores de gobierno nacional y subnacional-local, y poca participación del gobierno nacional en Argentina. Con respecto a la propuesta de gobernanza, se sugiere la creación de dos nuevas mesas (Desarrollo Social y Ambiental, y Seguridad Fronteriza), la promoción de misiones empresariales con una visión de integración regional y la preservación de los avances del Grupo de Trabajo del CVB. CVB (CVB Brasil Paraguay Capricornio embargo infraestructura participantes SNA [SNA] involucrados privado mayores país, país , país) subnacionallocal, subnacionallocal subnacional local, local subnacional-local Desarrollo Ambiental Fronteriza, Fronteriza Fronteriza) [SNA

Abstract The Bi-Oceanic Road Corridor (BRC) connecting Brazil, Paraguay, Argentina, and Chile is a Project designed to offer new development opportunities to peripheral regions in the Tropic of Capricorn. However, regional transformation requires more than just physical infrastructure; it particularly requires effective coordination among different actors to achieve development. The main objective of this study is to provide a detailed explanation of the actor network structure within the Bi-Oceanic Road Corridor and propose a potential governance approach that facilitates a better coordination among its participants. Using social network analysis (SNA), we explored the dynamics of participation amongthese actors. Our primary findings reveal a low level of private sector engagement, limited transnational links (with more interactions occurring among actors from the same country), scarce connections between national and subnational/local government actors, as well as minimal involvement of the national government in Argentina. Regarding the governance proposal, we suggest the creation of two new committees (Social and Environmental Development, and Border Security), the promotion of business missions with a regional integration approach, and the preservation of the progress made by the BRC Working Group. BiOceanic Bi Oceanic (BRC Brazil Paraguay Argentina Capricorn However infrastructure participants SNA, SNA , (SNA) engagement country, country country) subnationallocal subnational local proposal Social Development Security, Security Security) Group (SNA

RESUMEN En condiciones del trópico colombiano es necesario establecer estrategias de alimentación que permitan aumentar la productividad a bajo costo. El objetivo de esta investigación fue evaluar el efecto de la suplementación con ensilados de totumo, mango, guayabo de monte sobre la digestibilidad in vitro, degradabilidad y parámetros productivos en vacas doble propósito. El estudio fue realizado en la finca La Florida, ubicada, en el municipio de Puerto Boyacá, se usaron 32 vacas (Gyr x Holstein) con peso promedio de 460 ±35 kg en primer tercio de lactación, distribuidas en cuatro (4) grupos de ocho (8) cada uno, conformados de la siguiente manera: T1: grupo control: sin ensilajes; T2: ensilaje de Guayabo de monte; T3: ensilaje de Totumo y T4: ensilaje de Mango común. Todas las vacas permanecieron en pastoreo rotacional con Brachiaria decumbens, agua a voluntad y sal mineralizada. Se analizó el efecto del tratamiento, el tiempo y su interacción, para ello se usó el comando PROC MIXED del software SAS 9.2 (2002), la diferencias entre promedios se realizó mediante prueba de Tukey-Kramer, con nivel de significancia del 5 %. No hubo diferencias (p<0,05) en la producción diaria de leche entre los tratamientos evaluados, sin embargo, el porcentaje de proteína en leche fue mayor (p<0,05) en los tratamientos T2 y T4. EL NUL fue mayor en el T2 y menor en el T4. El consumo de ensilajes fue mayor (p<0,05) en el T4 y la condición corporal mostró ser mejor para los tratamientos T2 y T4, finalmente para los parámetros de degradabilidad y digestibilidad in vitro, los tratamientos T2, T3 y T4 obtuvieron los mayores valores respectivamente. La suplementación de vacas doble propósito con ensilajes de frutos del bosque húmedo tropical mejora la proteína de la leche y la condición corporal de las vacas. Los ensilados estudiados, poseen alta tasa de degradación y digestibilidad In vitro, representando una alternativa de alimentación en los rumiantes.

ABSTRACT In the Colombian tropic, it is necessary to establish feeding strategies that increase productivity and reduce costs. This research aimed to evaluate the effect of totumo, mango, and wild guava silage on in vitro digestibility, degradability, and productive parameters in dual-purpose cows. This study was carried out on a farm located in the municipality of Puerto Boyacá. Thirty-two Gyr x Holstein cows (Body weight = 460 ± 35 kg) in early lactation were enrolled and distributed in four groups of eight individuals: T1: control group: no silage; T2: Wild guava silage; T3: Totumo silage and T4: Mango silage. All the cows remained in a rotational grazing system with Brachiaria decumbens, water, and a salt-based mineral supplement ad libitum. There were no differences (p>0,05) in the daily milk production. However, protein levels in milk were higher (p<0,05) in the T2 and T4 treatments. NUL was more elevated in T2 and lower in T4. Silage consumption was higher (p<0,05) in T4, and the body condition score was higher for T2 and T4. For the degradability and digestibility parameters in vitro, treatments T2, T3, and T4 obtained the highest values. Fruits silage supplementation on dual-purpose cows with silage fruits can increase milk protein levels and body condition score. Those silages have a high rate of degradation and in vitro digestibility, representing a feeding alternative for ruminants.

RESUMEN Objetivo: Valorar la conducta diurna de ganado bovino productor de carne en finalización en el trópico seco. Materiales y Métodos: En el otoño se realizó un estudio observacional prospectivo con duración de cuarenta y dos días. A las 8:00, 12:00 y 16:00 h se registraron las pautas conductuales, temperatura ambiente y humedad relativa; el índice de temperatura y humedad fue calculado. Los bovinos permanecieron en corrales provistos de sombra de polipropileno y corrales sin sombra. Resultados: A las 8:00 h todos los bovinos estuvieron sujetos a condiciones ambientales de confort térmico (p<0.01); pero a las 12:00 h los bovinos bajo sombra estuvieron en peligro térmico y a las 16:00 h en alerta térmica, y a las 12:00 y 16:00 h en los bovinos sin acceso a sombra persistió el peligro térmico (p<0.01). El acceso al comedero se inhibió a las 8:00 y 12:00 h e incrementó a las 16:00 h, pero la rumia disminuyó a las 8:00 y 16:00 y aumentó a las 12:00 h (p<0.01). Los indicadores de descanso son mayormente observados en peligro y alerta térmica (p<0.01). Los indicadores agonistas se encuentran inhibidos a las 8:00 y 12:00 h (p≤0.04). La conducta social es mayormente manifiesta a las 16:00 h (p<0.001). Conclusiones: La expresión diurna de la conducta bovina relacionada con el factor climático y la provisión de sombra, puede ser inhibida en las horas de más alta influencia calórica expresada en el índice de temperatura y humedad.

ABSTRACT Objective: To assess the diurnal behavioral response of beef cattle in feedlot in the dry tropics. Materials and Methods: During fall, a prospective observational study was carried out for 42 days. At 8:00, 12:00 and 16:00 h, behavioral patterns, temperature and relative humidity were recorded, and the temperature and humidity index were calculated. Cattle were housed in pens provided with polypropylene shade and pens without shade. Results: At 8:00 h, the cattle under shade and cattle without access to shade were subjected to environmental conditions of thermal comfort category (p<0.01); but at 12:00 h cattle under shade were in thermal danger and thermal alert at 16:00 h. For cattle without access to shade at 12:00 and 16:00 h, the thermal danger persisted (p<0.01). Feed access was inhibited at 8:00 and 12:00 h and increased at 16:00 h, but rumination decreased at 8:00 and 16:00 h and increased at 12:00 h (p<0.01). Rest indicators were mostly observed in danger and thermal alert (p<0.01). The agonist indicators were inhibited at 8:00 and 12:00 h (p≤0.04). Social behavior was mostly manifest at 16:00 h (p<0.001). Conclusions: The diurnal expression of bovine behavior related to the climatic factor and the provision of shade, can be inhibited in the hours of highest caloric load expressed as the Temperature and Humidity Index.

Abstract In his pictorial exercises, David Orbea is known for simplifying forms found in various media, from press photographs to commercial products. Some of his series take on abstract qualities while retaining their ability to comment on the surrounding reality. For instance, in 2015, he intervened with boxes of mass consumer products, achieving an aestheticization that transcended the category of the objects used as support. By 2017, he focused on leadership books, allowing for social or political associations. In “Trópico Informal,” Orbea focuses on the chromatic schemes of urban constructions, creating a unique pictorial world. Additionally, he explores modern architectural elements and creates cement sculptures. His focus on tropical informality and abstraction results in a "dirty abstraction" that captures the identity of his original references. In this way, he preserves the popular in a sophisticated manner, elegantly capturing the symbolic essence that permeates the urban clamor.

Resumen En sus ejercicios pictóricos, David Orbea ha destacado por simplificar formas que encuentra en diversos medios, desde fotografías de prensa hasta productos comerciales. Algunas de sus series adquieren cualidades abstractas, conservando su capacidad para comentar la realidad circundante. Por ejemplo, en 2015 intervino cajas de productos de consumo masivo, logrando una estetización que trascendía la categoría de los objetos utilizados como soporte. Hacia 2017, se aplicó a libros sobre liderazgo, lo que permitía proyectar asociaciones sociales o políticas. En “Trópico Informal”, Orbea se enfoca en los esquemas cromáticos de construcciones urbanas, creando un mundo pictórico peculiar. Además, explora elementos arquitectónicos modernos y crea esculturas en cemento. Su enfoque en la informalidad tropical y la abstracción se traduce en una "abstracción sucia", que captura la identidad de sus referentes originales. De esta manera, preserva lo popular de manera sofisticada, capturando el simbolismo que atraviesa la estridencia de la vida urbana.

Resumen: El objetivo fue analizar la rentabilidad del proyecto de instalación de techos verdes extensivos en viviendas ubicadas en un clima tropical húmedo, considerando el efecto de diversos parámetros sobre la relación beneficio costo y el periodo de recuperación de la inversión. Los beneficios ambientales se estimaron a partir del análisis de ciclo de vida, mientras que el análisis de costos unitarios permitió determinar el efecto de la disponibilidad de materiales sobre los costos de instalación. El análisis monetizó dos beneficios ambientales: el ahorro de energía eléctrica y la captura de carbono, a partir del valor presente neto de los costos de instalación, mantenimiento, desmantelamiento y disposición final. Se determinó que la relación beneficio-costo varía entre 1.1 y 3.8 con periodos de recuperación de 3.4 a 8.9 años, en función de la disponibilidad de materiales, los indicadores económicos, las acciones de mantenimiento y la recompensa potencial con bonos de carbono al propietario.

Abstract: The objective was to analyze the profitability of the project for the installation of extensive green roofs on houses located in a humid tropical climate, considering the effect of various parameters on the benefit-cost ratio and the payback period of the investment. The environmental benefits were estimated from the life cycle analysis, while the unit cost analysis allowed determining the effect of material availability on installation costs. The analysis monetized two environmental benefits: electricity savings and carbon sequestration, based on the net present value of installation, maintenance, dismantling and disposal costs. The benefit-cost ratio was found to range from 1.1 to 3.8 with payback periods of 3.4 to 8.9 years, depending on the availability of materials, economic indicators, maintenance actions and the potential reward with carbon credits to the owner.