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

Background. In subtropical latitudes, where goats are typically raised in rangeland conditions, daily solar radiation may strongly impair reproductive activity in male goats, thus decreasing their fertility. Objective. To assess the effects of solar radiation on plasma testosterone concentrations, sperm production and fertility in well-nourished male goats over the course of 1 year. Methodology. Control males were kept in a shaded pen (n = 5), whereas the solar-exposed males remained in an unshaded pen exposed to direct solar radiation (n = 5). In experiment 1, plasma testosterone concentrations and sperm production were measured. In experiment 2, fertility of solar-exposed and control males was determined when joined with anestrous female goats. Results. Plasma testosterone concentrations varied over time (P < 0.0001), and there was an interaction between time and the groups of bucks (P < 0.001). In solar-exposed males, testosterone concentrations were lower than controls in June, September, December and January (P < 0.05). The total number of spermatozoa per ejaculate and progressive sperm motility varied over time (P < 0.0001), but there was no interaction between time and groups (P > 0.05). The percentage of live spermatozoa and the percentage of cells with abnormalities varied over time (P < 0.0001), and there was an interaction between time and treatment group (P < 0.0001). In solar-exposed males, the percentages of live spermatozoa were lower than controls in June, August, November and December, while in May, this percentage was higher in solar-exposed males than in controls (P < 0.05). The percentage of abnormal spermatozoa was higher in solar-exposed males than in controls from June to December (P < 0.001). The percentage of females that kidded was lower in those joined with the solar-exposed (48%) compared with those joined with control males (79%; P < 0.001). Implications. Providing shade reduces the negative effects of solar radiation on sperm quality and buck’s fertility. Conclusion. Daily exposure to solar radiation deeply altered reproductive activity of bucks. Testosterone concentrations, qualitative sperm production and fertility, were much lower in solar-exposed bucks compared to the control bucks kept under shade. 

Antecedentes. Los insectos pueden coadyuvar a la seguridad alimentaria, la FAO propone a este recurso como pilar importante hacia la alimentación del futuro. Objetivo. Analizar la producción científica sobre insectos comestibles para conocer la tendencia actual sobre esta línea de investigación y los vacíos de conocimiento. Metodología. Se aplicó un análisis bibliométrico, para ello se identificaron relaciones entre países, autores y revistas, considerándose el periodo 2014-2023. Resultados. El autor, revista y país con mayor impacto científico ligado al estudio de insectos comestibles fueron: Adámková, A, Foods y Polonia, respectivamente. El tema de mayor desarrollo está ligado al análisis de alimentos (piensos), valor nutricional, metabolismo y experimentos con animales sobre dietas elaboradas a partir de insectos. Se mostró una proyección de estudio científico dirigido al análisis de alimentos y la sustentabilidad. Implicaciones. Este trabajo solo presenta información disponible en la base de datos de Scopus, esto por ser un recurso de alcance mundial, útil para la difusión del conocimiento científico, se limita a considerar trabajos publicados en buscadores de menor alcance.  Conclusiones. Se logró analizar la producción científica relacionada a los insectos comestibles y factores asociados, exhibiéndose la tendencia actual sobre esta línea de investigación y sus vacíos de conocimiento. Se visualizan áreas de oportunidad para la comunidad científica, como una estrategia que coadyuve a la seguridad alimentaria.     

Background: Utilizing improved forage grasses such as Napier (Pennisetum purpureum, acc. 15743), Desho (Pennisetum glaucifolium), and Gunia (Panicum maximum) grasses with proper management practices has the potential to solve the feed scarcity challenges in Ethiopia. Objective: To evaluate the effect of vermicompost (VC) and urea on the morphological characteristics and dry matter yield (DMY) of Napier, Desho, and Gunia grasses, as well as soil chemical properties across different altitudes of northwestern Ethiopia. Methodology: The experiments were conducted at mid and high-altitude locations using a Randomized Complete Block Design (RCBD) with a factorial arrangement and three replications. The treatments used were control (no fertilizer), 100% Vermicompost, 100% urea, 30% urea + 70% vermicompost, and 70% urea VC +30% vermicompost. Morphological parameters like plant height (PH), number of tillers per plant (NTPP), number of leaves per plant (NLPP), and Leaf length per plant (LLPP) were measured. The DMY t ha−1 and leaf-to-stem ratio (LSR) were also measured. Soil chemical properties were analyzed before and after forage cultivation, and the composition of vermicompost was also analyzed. Results: Results showed that fertilizer treatments positively influenced the morphological parameters, DMY t ha−1, and soil chemical properties compared to the control treatment. Combined application of urea and vermicompost generally performed better than individual application, however, the difference among the combined treatments was not statistically significant. Better performance of forage grass was observed at the mid-altitude compared to the high altitude, with Napier grass showing the highest DMY t ha−1. Implications: The findings highlight the importance of altitude, forage grass species, and fertilizer application in enhancing soil chemical properties and productivity of forage grasses in Ethiopian farming systems. The combined use of vermicompost and urea shows promising potential and could be prioritized to optimize forage grass production. Conclusion: The application of vermicompost, urea, and their combination significantly improves the morphological parameters, DMY t ha−1, and soil chemical properties compared to the control treatment. To sustainably improve the productivity of livestock feed resources in Ethiopia, integrating improved forage varieties with enhanced agronomic management practices, particularly proper fertilizer application, is strongly recommended. 

Background. Livestock activities generate changes in ecosystems that impact bird communities, which fulfill diverse ecological functions such as pollination, fruit and seed dispersal, and biological control of insects and/or pests. Objective. To characterize the community of birds in a livestock landscape in northern Veracruz. Methodology. From 2020 to 2021, 144 visits were made to live fences (CV; n = 3) and cattle pastures (PA; n = 3), where the fixed-radius point count technique was used to identify and count the birds present. Results. A total of 6,450 individuals and 107 species were recorded. In general, the CVs were more diverse than the PAs, although the PAs were more dominant. The importance value index reflects that in the VCs the importance of the species is similar, while in the PAs certain species stand out, however, at the level of trophic guilds, insectivorous birds dominate. Through a canonical correspondence analysis, three community assemblages were distinguished: one station in the VCs, one station in the APs and the rest of the stations. Implications. The work suggests further studies that will allow us to know why birds are using these man-made livestock systems. Conclusion. The live fences obtained greater diversity, so it is necessary to integrate more trees within the pastures to increase the ecological functions, such as the control of insects through insectivorous birds.

Background. The desalination process is key to addressing water scarcity; however, it faces challenges such as the environmental impact of brine. Several strategies minimize this impact, including the use of halophytes. Salicornia bigelovii is a halophyte with multiple benefits. The phenological stages of germination and seedling are the most susceptible for establishment. In arid areas, agriculture depends on salinity-resistant plants to mitigate problems of soil degradation and water scarcity. Objective. To evaluate the impact of edaphic conditions and irrigation salt concentrations on the emergence and initial development of Salicornia bigelovii. Methodology. Part 1. Sowing was carried out in germination trays with three types of substrate and irrigated with fresh water for 50 days. Part 2. Sowing was carried out in peat moss substrate, four saline irrigation water treatments were applied: 0 M, 0.05 M, 0.10 M and 0.15 M. The variables evaluated were the percentage of emergence, plant height, root length, number of root hairs, fresh weight and plant dry weight. Results. The emergence percentage was affected by the physicochemical characteristics of the substrates and the salts present in the irrigation water, with no emergence observed at higher saline concentrations. In the morphometric parameters, it was observed that as the saline concentration in the irrigation water increased, there was a decrease and even complete inhibition of emergence at concentrations of 0.10 M and 0.15 M.  Implications. By identifying the appropriate substrate for the cultivation of salicornia, it will be possible to select areas with greater potential for cultivation and, in addition, the sustainable use of brine as irrigation water will be promoted. Conclusion. Substrates with high salinity values and high saline concentrations in the irrigation water show a decrease in crop emergence and in the morphometric variables evaluated, demonstrating the adverse effect of increased salinity and therefore certainty in the establishment of a Salicornia-based crop.

Antecedentes. En la producción de maíz, el agua de riego como un insumo con valor monetario debería incrementar el beneficio en especie; la lluvia es la fuente más sustentable de agua, pero no asegura el beneficio. Objetivo. Evaluar la respuesta agronómica de híbridos de maíz bajo riego y secano en dos densidades de siembra. Metodología. El diseño del experimento fue factorial en bloques completos al azar y tres repeticiones con: genotipos (G), díez materiales (G1…G10), dos niveles de humedad (H) como riego (H1) y secano (H2), dos densidades de siembra (D) con D1= 55 mil plantas ha-1y D2=75 mil plantas ha-1, en dos ambientes (A) del Estado de México; Cuautitlán (A1) y Texcoco (A2). Resultados. La media general del rendimiento de grano fue 7.1 t.ha-1 y el uso del agua 10.7 kg.mm-1. Los resultados de estas variables para los factores: el híbrido (IA249AE X FSN 87) X GNF resultó con las medias más altas 8.9 t.ha-1 y 13.35 kg.mm-1; el riego presentó rendimiento mayor de 7.39 t.ha-1, pero bajo secano fue superior el uso del agua con 11.41 kg.mm-1; así también, Cuautitlán fue superior con 9.4 t.ha-1 y 13.4 kg.mm-1; además, la densidad D1 fue superior con 7.19 t.ha-1 y 10.75 kg.mm-1. Las interacciones de primer orden fueron significativas, por lo menos en una variable respuesta. Implicaciones: Se requieren investigaciones adicionales sobre productividad del agua del cultivo de maíz en sitios de la Cuenca de México para identificar el potencial de los genotipos.  Conclusión. La disponibilidad de agua por lluvia tuvo efecto mayor que el riego en rendimiento de grano y uso del agua de los híbridos de maíz en Cuautitlán y el riego resultó contraproducente en ese sitio. La densidad de población mayor responde a medida que se dispone de más recursos como el agua.

Antecedentes. La fruticultura en México es una actividad de importancia económica. Estos cultivos se ven afectados por distintos tipos de patógenos, dentro de los que sobresalen los nematodos, debido a las pérdidas económicas que generan a nivel mundial en los cultivos frutales infectados. Por lo anterior, es fundamental la identificación morfológica y molecular, así como, utilizar estrategias de control integral del nematodo patógeno. Objetivo. El objetivo de esta revisión fue analizar los avances en la identificación de los nematodos presentes en los cultivos frutales en México, y las estrategias de control utilizadas actualmente. Metodología.  Se realizó una revisión sistemática para recopilar, sintetizar y evaluar la literatura científica disponible, sobre la identificación y control de nematodos fitoparásitos asociados a frutos de importancia económica en México. Se consultaron las bases de datos PubMed, Scopus, Web of Science, SciELO y Google Scholar, utilizando palabras claves en inglés y español. Resultados. Los principales géneros de nematodos fitoparásitos en frutales son Aphelenchus, Ditylenchus, Helicotylenchus, Paratylenchus, Pratylenchus, Rotylenchulus, Rotylenchus, Trophurus, Tylenchorrhynchus, Tylenchus y Meloidogyne, destacando este último como el más prevalente. La identificación se basa principalmente en caracteres morfológicos y morfométricos; el diagnóstico molecular es limitado y generalmente se enfoca en la amplificación de dos regiones genéticas específicas ITS y SCARs. Las estrategias de control químico, biológico y genético se han enfocado en el control de Meloidogyne. Implicaciones.  La presente revisión destaca la importancia de una gestión integral y basada en evidencia para abordar los problemas asociados con los nematodos fitoparásitos en los cultivos frutales de México. Conclusiones. La identificación precisa de estos patógenos, tanto morfológica como molecularmente, es crucial para implementar estrategias de control efectivas, destacando la necesidad de desarrollar enfoques más integrales y precisos para mitigar el impacto de estos patógenos en la fruticultura mexicana.

Background. Forest fires play an important role in ecosystems; however, uncontrolled wildfires can damage ecosystems and emit CO2 into the atmosphere. The state of Chiapas ranks among the top ten places in Mexico in terms of the frequency of forest fires and the area damaged by them. The occurrence of fire and damage is the result of the complex interaction of social, climatic, and biophysical factors. Objective. To analyze the spatio-temporal dynamics of forest fires in the state of Chiapas during the period 2010-2024, as well as the leading causes of these events and their relationship with the trends of climate change. Hypothesis: The recurrence of forest fires can be explained by patterns of climate change.  Methodology. The work was carried out by analyzing historical records of wildfires, as well as the trends of climatic variables, especially temperature and precipitation. The fire-prone areas were identified using the intersection of polygons across a temporal series in a Geographic Information System. The relationship between the recurrence of wildfire and climatic variables was determined by correlation and regression analysis. Results. The recurrent areas correspond, in great part, to the Sierra Madre of Chiapas, which, due to its physical-geographical characteristics, makes it prone to fire development. Likewise, during 2021-2024, the greatest fire damage was observed, mainly in areas where broadleaf and conifer vegetation predominates. Conclusion. The increase in the recurrence of forest fires in Chiapas is not entirely attributed to current climate trends; rather, part of these events is also related to anthropogenic causes and inadequate fire management, primarily due to agricultural activities. It is observed that these events are more frequent during the dry season, mainly between April and May. Implication. This type of research enables us to identify the primary conditions that favour wildfires and their relationship with climate change. The results will help in developing forest fire prevention and mitigation strategies.

Background: The use of Morus alba L. forage can improve the productive parameters of ruminants in periods of forage scarcity, due to its high biomass yield and crude protein content, which surpass those of tropical grasses that typically contain high fiber concentrations compared to this tree species. Objective: To evaluate the effect of three harvest intervals (30, 60 and 90 days) and three cutting heights (50, 75 and 100 cm) on the biomass yield and chemical composition of M. alba. Methodology: The yields of leaves, tender stems, mature stems, edible material, and total biomass were evaluated. Additionally, the contents of organic matter (OM), ash, acid detergent fiber (ADF), neutral detergent fiber (NDF), and crude protein (CP) in leaves and tender stems of M. alba were analyzed at different harvest intervals and cutting heights during the rainy and dry seasons. The data were subjected to an analysis of variance for a completely randomized design with a 3 × 3 factorial structure. Results: The harvest interval significantly affected the evaluated yield variables. Biomass yield was higher when harvested every 90 days compared to 30- and 60-day intervals. Regarding the chemical composition of leaves and tender stems, it was observed that the harvest interval affected it the most. The interaction between both factors influenced the contents of organic matter (OM), ash, and neutral detergent fiber (NDF) in the leaves, with high contents observed at 90-day intervals and a cutting height of 75 cm. Implications. These findings are important for the management and optimal use of this forage species in animal feed and can contribute to the development of more efficient and sustainable livestock systems. Conclusion: The yield and chemical composition of M. alba are more affected by the harvest interval than by height and interaction. Therefore, it is essential to consider this factor in its management to develop more efficient and sustainable livestock systems.

Background: Assisting sows during parturition reduces the number of stillborn piglets caused by anoxia. However, in industrial settings with a large number of animals, the capacity for assistance is limited. The development of predictive models based on existing data can enable farms to anticipate stillbirths in sows. Objective: To develop a predictive model to identify factors affecting the presence of stillborn piglets (PSbP), estimate the probability of their occurrence, and establish a classification criterion accordingly. Methodology: Data from 2 415 farrowings in 822 sows (Landrace, Yorkshire, and their crossbreeds) were analyzed. Five variables relating to the current farrowing and five variables related to the preceding one were examined. Our study used cross-validation (groups = 5), modeling the response variable (PSbP, 1: presence, 0: absence). Results: The only factor shown to have a negative effect (p<0.01) on PSbP was litter weight at birth, while litter size at birth and parity (number of farrowings) were seen to have a positive effect (p<0.01). PSbP prevalence during training and testing were 0.297 and 0.296 respectively. The model's estimated probability levels were 0.311 during training and 0.303 during testing, indicating an accurate probability estimation. When categorizing using the optimal cutoff point of 0.395, the predictive efficiency as measured by the area under the Receiver Operating Characteristic (ROC) curve was 0.846 for training and 0.813 for testing. Implications: Implementing this model of information-management software could make it possible to provide swift, efficient technical assistance to sows in need, with a high level of predictive efficiency. Conclusions: The probabilistic model described here based on a Bayesian approach and adjusted based on a categorization criterion showed effective predictive efficiency in the prediction of stillborn piglets.