Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

The research question is how do some biotic and abiotic variables, under a silvopastoral system exert influence on the animal movement? These studies have been carried out through different approaches and have included analyses from empirical to statistical. The aim of this study was to relate cattle grazing sites with some biotic and abiotic factors under a silvopastoral system. The fieldwork was carried out in a paddock of the farm La Reforma located in the upper part of the Magdalena River basin (Tolima, Colombia). Through global positioning devices (GPS), movement, grazing route, and resting data that cattle perform in these habitats during daytime hours were obtained. Six cows (460 kg live weight, not pregnant) were monitored during two periods of the year at one-minute time intervals. Data were processed in a geographic information systems (GIS) environment, and mechanisms and algorithms were used to establish an association of moving animals with some biotic (pasture productivity and cover, trees, and floristic composition) and abiotic factors (climatological season, access to drinking and salt troughs). The results suggest an association between animal movement concerning the different attractants for which the drinking and salt troughs in the paddocks were relevant. In conclusion, the analysis of animal behavior at the landscape level is useful for decision-making in the design of livestock landscapes.

Coffee quality is generally evaluated through cupping, a technique based on sensory perceptions. Trained cuppers assign scores to ten quality attributes on a scale of 1 to 10. Exposure of coffee to moisture and/or oxygen during storage and/or transportation can affect the sensory evaluation and reduce the price received by farmers. This paper has two objectives. First, it estimates the effect of sensory scores and water activity on coffee price and its price differential from the market price. Second, it explores coffee sensory scores sensitivity to storage duration and water activity under two methods of application of the Purdue Improved Crop Storage (PICS) bags - the standard three layers PICS bag (PICS-3L) and the two layers PICS bag (PICS-2L). Data were collected for ten months from an experiment conducted in Manizales, Colombia. Results suggest, on average, that an additional point in the score of flavor or body increases the price of coffee by at least 66 COP/kg (0.015 USD/kg). If coffee has an additional point in aftertaste or uniformity from what is expected from other coffees of the same origin, then its price differential is reduced by at least 8 COP/kg (0.002 USD/kg). Using a PICS-3L bag instead of a PICS-2L bag does not affect the coffee price or sensory scores, but it reduces the price differential by approximately 18 COP/kg (0.004 USD/kg). On the other hand, water activity reduces coffee price but not its price differential. Storage time affects coffee sensory scores in some attributes, which may impact the coffee bean price.

The hematic parameters of cows selected for milk production in grazing under tropic conditions were analyzed based on six experimental studies. The major objective was to determine statistical analysis alternatives that could be used in the study of physiological, environmental or genetic variations. The parameters analyzed were hematocrit, hemoglobin concentrations and counts of polymorphonuclear cells (i.e., eosinophils, basophils, neutrophils and lymphocytes). Initially 972 data from adult cows with productions considered medium-high in the context of local dairy production were analyzed. After the information decanting process, 415 records were used. These data corresponded to a sampling period from 30 days before calving to day 105 postpartum, with determinations made fortnightly.  Blood collection was made every two weeks and each moment was defined as a period. Different analytical techniques were applied in searching to extract the best information from the data and that could be reused in the future. The best type of analysis corresponded to the Random Forest (RF) technique, clustering, and analysis of variance.The effect of an indicator of energy metabolism (non-esterified fatty acids - NEFA), an indicator of protein metabolism (total protein - TP) of 10 collection periods, three breed groups and three types of nutritional management given to the animals on the blood variables were analyzed. Multivariate correlation and machine learning methods were used to extract information from the data. Results indicated that hematological behavior change throughout close up dry cow, transition period and first phase of lactation. No high direct or inverse correlation were found among variables. Hematocrit and hemoglobin levels can be estimated from variables associated with metabolic indicators and blood components. Further studies are required to elucidate the hematic behavior of dairy cows during the transition period.

Nariño (Colombia) has high dairy potential; however, their herds present difficulties in the nutritional component (energy imbalance) of the cows, affecting their productivity. This research evaluated the effect of a bypass fat supplement on lipid concentration in milk and the reproductive efficiency of dairy cows. The study was based on 21 Holstein x Simmental cows between first and third calving and the following was supplied: forage + concentrate (T1); forage + concentrate + 250 g/day of bypass fat (T2) and forage + concentrate + 250 g/day of bypass fat enriched with omega-three (T3). The experiment was conducted from day 15 pre-calving until day 105 of lactation. During this period, milk quantity, quality, composition, and reproductive behavior were recorded. For data analysis, a repeated measure mixed design with time-series data was used, where the fixed effects were the treatments, periods, and their interaction, the animals represented the random effect, and the covariable was the estimated milk yield during lactation. The results showed normal mobilization of adipose tissue; the compositional quality of the milk did not vary across treatments, although T2 presented a higher estimated production per lactation, and T3 presented a higher percentage of fatty acid C18:2. In the reproductive indicators, they were not influenced between the treatments; concluding that the base diet offered in the herd presents a nutritional balance appropriate to the requirements of the cows in production.

Pineapple is the third most-produced tropical fruit worldwide; however, it is a crop that, due to its management, can lead to the generation and intensification of processes such as soil erosion. This paper presents a bibliographic review about the factors that influence erosion in soils dedicated to pineapple cultivation, addressing papers reported in the international literature, subsequently positioning it in the context of the main producing municipalities presented in the Valle del Cauca region. The available research covers the last four decades, where losses are estimated between 35 and 178t ha-1year-1; the topography, the conditions of the access roads, some management practices, and edaphic properties related to erodibility stand out among the most critical factors. Finally, based on the climatic, edaphological, and topographic traits reported in the literature for the main pineapple producing region of Valle del Cauca, and considering current management practices, it is found that this area can present very high erosion values since the soils are susceptible, and the slopes are steep, some of them even higher than 70%. Therefore, it is suggested to carry out more research to determine the erodibility and erosivity of these areas to know the potential degradation index, which will function as a valuable tool for decision-making, the generation of management, and conservation recommendations of these soils.

The 'Anna' apple is a variety of low requirements of winter chill (250 to 300 chilling hours ≤7.2°C). This apple has essential health benefits and remarkable adaptive potential in tropical and subtropical areas affected by climate change. Thus, this review presents the significance of the 'Anna' apple cultivation, the phenological and eco-physiological modifications, and the current state of agronomic management when continuous crops are managed in tropical highlands. The production of this apple in tropical highlands has outstanding potential to obtain cyclical or continuous harvests (two harvests per year) in certain areas with specific environmental conditions, implementing a particular management system. In plantations, it is crucial to carry out some agronomic practices during the reproductive phenology so that the apple tree does not enter into an endodormancy. These are water stress - defoliation – tie-down branches, and the application of dormancy-breaking agents (flower-inducing compounds). In Colombia, ‘Anna’ variety was introduced in 1985 and is grown in areas with temperatures between 14 and 20°C, altitudes between 1700 and 2800 meters above sea level (m a.s.l.), with bimodal and monomodal rain regimes, and solar brightness between 800 and 2000 hours a year. The harvest is between 100 to 120 days after anthesis, with firmness values of 38.38N, a soluble solids content of 8.58°Brix, and total titratable acidity of 0.7% of the fruit. This documentation indicates a good production with great potential in terms of growth and development, earliness, and quality of the 'Anna' apple tree in Colombian highlands.

With the intensification of the problems encountered in agriculture, the use of microorganisms shows promise. Fungi of the Trichoderma genus are found naturally in the soil and have been; they are used as an active ingredient in biofungicides and have activity as promoters of plant growth. This work aimed to evaluate the efficiency of the commercial product TrichoPlus, containing Trichoderma asperellum (Samuels, Lieckf & Nirenberg) as a promoter of soybean plant growth. Four independent experiments were carried out in different periods between 2019 and 2020. The experiments were conducted in a greenhouse, and biomass and nutrient contents were examined. In the first experiment, among the different rates of TrichoPlus tested (3, 4, 5, and 6 g per kg of seeds), the best dose for most of the characteristics evaluated was 5 g per kg of seed. Hence, the inoculation of TrichoPlus at 5 g per kg of seed in the other experiments showed positive results in the accumulation of biomass, nitrogen, and phosphorus content. Based on the study's results, the product TrichoPlus, composed of T. asperellum, can be used as an efficient inoculant for promoting soybean plant growth.

The need to produce domestic strawberry transplants leads to the search for low-cost cultivation media in Brazil. Raw rice husk (CAIN) is an abundant and economical material in the south of the country. This study aimed to evaluate three substrate conditioners (35%) [carbonized rice husk (CRH), vermiculite and the commercial substrate S10®] added to RRH (65%) and their effects on growth, production and quality of strawberry transplants grown on benches with recirculation of nutrient solution, in a greenhouse. The experimental design was in causal blocks with three treatments and four replicates. Two mother plants of the Aromas cultivar were grown on each plot between November/2016 and March/2017. Transplants were classified into groups according to crown diameter (Class 1: 3.0-5.0 mm; Class 2: 5.1-8.0 mm; Class 3: >8.1 mm). Similarly, the number of leaves, leaf surface, fresh and dry mass of leaves and crowns of 10 transplants belonging to each class were evaluated. With the addition of CAC and vermiculite to the substrate, the predominance of class 2 transplants was obtained. The addition of S10 to CAIN increased the total number of transplants, as well as the number of leaf surface transplants and the dry mass of the aerial part of plants, in class 3 transplants, as well as S10 and vermiculite, provided a greater number of propagules produced.

In conventional agricultural production systems, soil management is generally carried out without considering the spatial variability of its properties. This situation generates not only soil degradation but also an increase in production costs associated with the management of this factor. The objective of this research was to evaluate, through geostatistical methods, the spatial variability of soil fertility in Botana Experimental Farm of Universidad de Nariño. Spatial variability maps were estimated using the ArcGIS 10 program, the Kriging interpolation method, and the optimal ranges of soil fertility for the Andean region as projection parameters for making decisions related to land use. The fertility zoning of the farm was established, classifying soil as having high, medium, and low fertility. Most of the experimental farm had low fertility soils (20.7ha), and only 3ha had good conditions. Statistical analysis indicated a high variability in soil chemical properties. Properties such as pH and bulk density showed low variability.

The fungus Fusarium verticillioides produces fumonisins (FB1 and FB2), characterized by being the most frequently produced molecular forms and with greater toxicity. Fumonisin contamination is responsible for substantial losses during the meat production chain, so the safe levels of these compounds must be determined. The study was directed to establish safe levels of FB1 in poultry production; for this purpose, were used COBB 500® birds on experimental lots of infected corn during the 2015/2016 season in Brazil. The experimental group included 160 animals, divided into two groups: The T1 without fumonisin in the diet (control); and the T2 group in which corn was contaminated with 2.78 μg/g of fumonisin FB1. Histopathological effects of liver, heart, and small intestine, and zootechnical parameters were measured in birds treated. We found that there were no significant differences between the birds treated and untreated after 21 days of exposure to each treatment; F-values > P-values (P<0,05) for feed intake and weekly weight gain. Taken together, our data showed that the concentration evaluated is safe in poultry and will contribute to the design of future clinical studies.