There are few reports on dual-purpose cattle systems characterization in Latin America and Colombia based on large datasets. This limits our understanding of their dynamics, and the establishment of public policies and government programs to improve their productive performance, promotion and rural development. This study aimed to characterize very small, small, medium, and large dual-purpose farms in Colombia from technical and environmental perspectives. The data analysed were obtained from the Ganadería Colombiana Sostenible and the LivestockPlus projects, which gathered information from a total of 1313 dual-purpose farms in Colombia. Farms were classified as being either very small (1 to 30 bovines), small (31 to 50 bovines), medium (51 to 250 bovines), or large farms (more than 251 bovines). Numerical and categorical variables were distributed into five components: (1) General Farm Information, (2) Herd Composition and Management, (3) Pasture Management, (4) Production Information, and (5) Environmental Information. Each component was analysed using the factorial analysis of mixed data (FAMD) method. According to FAMD, for the components General Farm Information, Herd Composition and Management, Pasture Management, and Production Information, the distribution of variables led to a spatial separation of the centroid from each category of producers. For the component Environmental Information, there was no separation of the centroid. In general, medium-sized and large farms showed better infrastructure, better machinery and equipment, and better reproductive practices; however, this was not reflected in a significant improvement of productive parameters, except for a lower mortality rate. Larger livestock producers need to plan their livestock husbandry activities properly, based on their better available infrastructure and livestock management practices, with the purpose of increasing productivity. The main features identified for each livestock producer category can be the basis to guide and establish policies and programmes for their technological development. The development of better livestock management practices and the implementation of technology, as well as technical assistance, should focus on small- and medium-sized livestock producers, which could lead to reaching a better productive and reproductive performance of dual-purpose systems.

The intensive cattle production on the Colombian Atlantic coast causes soil degradation and low productivity on pastures. Silvopastoral systems in Colombia are based on introduced species due to a lack of native species knowledge and a cultural trend to overestimate introduced species. It is necessary to study native species in association with the established pastures to increase productivity and to improve soil properties. This research was based on the Sinú River Valley (18 masl), under Tropical dry forest, in Colombia. The aim of this study was to determine changes in nutrient cycling when native trees are incorporated into grassland systems, according to their diversity. Leaf litter decomposition of two grass species and seven forestry native species were evaluated on four experimental blocks. The results showed that residual dry matter decreased over time and facilitated nutrient release associated with species diversity and its interaction. Nutrient liberation was specie-dependent being markedly higher on G. ulmifolia and P. quinata. The concentration of N/P, P, and Mg was significant and had the highest correlation with leaf litter decomposition. The tested decomposition models showed good performance and small significant differences between them, which confirms its reliability to use them under Colombian tropical conditions.

The operating conditions of polyhydroxybutyrate (PHB) production processes are among the factors that most influence yields. In this study, we evaluated PHB production synthesized by Bacillus megaterium LVN01. Batch and fed-batch cultures were used to produce PHB from residual glycerol. For this, dry cell weight (DCW) and PHB productivity were analyzed at a preliminary stage by central composite design using batch systems under different temperature, C/N ratio, and fermentation time conditions. The maximum PHB productivity occurred at 30.8 °C, 44.9 mol mol-1, and 39.9 h. The same conditions were tested for studies in fed-batch culture. Fed-batch experiments were comparable to each other, where the DCW was around 1.9 g L-1, with PHB productivities of 29.5 mg L-1 h-1 and 35.6 mg L-1 h-1 for bioreactors of 5 L and 14 L, respectively. The PHB was characterized by NMR, FTIR, DSC, TGA, and DTG analys

The most important issues that affect consumer fruit acceptance in the ‘Hass’ avocado international market are flesh disorders. These defects can be influenced by both pre- and postharvest factors. The aim of this work was to evaluate the effect of the harvest season, storage time, mineral content, and preharvest variables on internal fruit disorders. Here, fruit was sampled from four farms in Antioquia (Colombia) at 22%, 26%, and 30% dry matter (DM) content. Samples were stored and ripened under simulated export conditions. Then, flesh bruising, flesh discoloration, body rots, vascular browning, stem end rot, and mineral content were assessed. The results showed that flesh disorders differ among farms and by harvest index and storage time. The most frequent defects found were vascular browning and stem end rot. Boron, calcium, nitrogen, manganese, magnesium, and potassium have a strong relationship with flesh disorders. Therefore, high boron and calcium contents, as well as a harvest at 26% DM, can substantially reduce avocado flesh disorders and improve internal fruit quality. Farmers that had a high flesh and soil mineral content and low rainfall and temperature produced fruits with fewer internal disorders.

En Colombia, la cría bovina representa el 15% del inventario ganadero, siendo un eslabón importante en la cadena de producción de carne. La carencia de estudios de caracterización limita la adecuada planificación técnica y ambiental de esta actividad. El objetivo de este estudio fue caracterizar los parámetros técnicos y ambientales de fincas de cría con doble utilización de la vaca, pertenecientes a muy pequeños (MPG), pequeños (PG), medianos (MG) y grandes productores (GG). La información se obtuvo de los proyectos Ganadería Colombiana Sostenible y Livestock – Plus. La muestra total fue de 2618 fincas, que fueron clasificadas de acuerdo con su orientación productiva: cría, ceba, doble propósito, lechería especializada e integral. Las 251 fincas de cría se estratificaron en MPG (1 a 30 bovinos), PG (31 a 50), MG (51 a 250) y GG (más de 251). Se consideraron variables numéricas y categóricas, las cuales fueron clasificadas en cinco componentes: información general, composición y manejo del hato, manejo de potreros, información productiva y reproductiva e información ambiental. Cada componente se analizó mediante un Análisis Factorial para Datos Mixtos (AFDM). En los primeros cuatro componentes, las variables conllevaron a una separación espacial del centroide de cada categoría de productores. Los MG y GG estuvieron asociados con variables que indicaron la existencia de mejor infraestructura, maquinarias y equipos, y mejores prácticas y parámetros reproductivos y productivos. No existieron diferencias en el desarrollo de prácticas ambientales. Las características identificadas pueden servir para el establecimiento de políticas públicas de desarrollo tecnológico y gestión ambiental.