Silvopastoral systems and remnant forests enhance carbon storage in livestock-dominated landscapes in Mexico.

A large area of the terrestrial land surface is used for livestock grazing. Trees on grazing lands provide and can enhance multiple ecosystem services such as provisioning, cultural and regulating, that include carbon sequestration. In this study, we assessed the above- and belowground carbon stocks across six different land-uses in livestock-dominated landscapes of Mexico. We measured tree biomass and soil organic carbon (SOC) stocks in fodder banks, live fences, pasturelands with dispersed trees, secondary forests, and primary forests from three different geographical regions and compared them with conventional open pasturelands respectively. We also calculated tree diversity indices for each land-use and their similarity with native primary forests. The aboveground woody biomass stocks differed significantly between land-uses and followed the gradient from less diverse conventional open pasturelands to silvopastoral systems and ecologically complex primary forests. The SOC stocks showed a differential response to the land-use gradient dependent on the study region. Multivariate analyses showed that woody biomass, fine root biomass, and SOC concentrations were positively related, while land-use history and soil bulk density showed an inverse relationship to these variables. Silvopastoral systems and forest remnants stored 27-163% more carbon compared to open pasturelands. Our results demonstrate the importance of promoting appropriate silvopastoral systems and conserving forest remnants within livestock-dominated landscapes as a land-based carbon mitigation strategy. Furthermore, our findings also have important implications to help better manage livestock-dominated landscapes and minimize pressures on natural protected areas and biodiversity in the hotspots of deforestation for grassland expansion.

Shiga toxin-producing Escherichia coli O157 in piglets and food from backyard systems.

Piglets suffer from diarrhea caused by the Shiga toxin-producing Escherichia coli (STEC) and can be carriers of the bacteria, with public health consequences in developing countries. The aim of the present study was to study the prevalence of STEC O157 in feces of 465 piglets and 54 food mixes from backyard systems, the antimicrobial susceptibility of STEC and the frequency of genes encoding extended-spectrum ß-lactamases. The E. coli was isolated from 75.90 % of the evaluated feces. The STEC strains were identified in 33.11% of the sampled population and in 43.60% of the piglets carrying E. coli. Among STEC strains, the stx1 gene was the most frequent (22.30%). The rfbO157 gene was amplified in 47.40% of the STEC strains. High frequencies of STEC strains were not susceptible to ampicillin, carbenicillin and tetracycline. The blaTEM gene (52) was the most frequent among strains not susceptible to ampicillin. Class 1 integrons were the most frequent in those strains. Of the identified STEC strains, 48.70% were considered as multi-drug resistant and 1.90% were considered extensively drug resistant. In the supplied food, STEC O157 strains were identified in 25.00% of the STEC strains. We conclude that the piglets from backyard systems are carriers of STEC O157 strains not susceptible to common antibiotics, including penicillins and tetracyclines. In addition, supplied food is a source of this type of pathogenic bacteria. Through their direct contact with humans, the piglets and food represent a potential source of bacterial dissemination capable of producing gastrointestinal infections in humans.

Caracterización y tipos de familias productoras de maíz local en la Frailesca, Chiapas / Typological characterization of the maize producing families from la Frailesca, Chiapas

Resumen Las Unidades de Producción Familiar (UPF) están conformadas por capitales natural, físico, financiero, humano y social. Los dos últimos constituyen la base del funcionamiento del resto y de la unidad de producción. En México, Chiapas y la Frailesca, la producción de maíces, particularmente de maíces locales, tiene valor cultural, agronómico y económico. El objetivo de esta investigación fue caracterizar las Unidades de Producción Familiar que cultivan maíces locales en la región Frailesca del estado de Chiapas, sobre la base cultural del manejo de los capitales humano y social. Se estudiaron 80 UPF de 20 comunidades seleccionadas mediante un muestreo por redes. Se utilizó el enfoque Modos de Vida Sustentable como marco de referencia. Se aplicaron entrevistas semiestructuradas y se realizaron observaciones participantes. En el estudio predominaron las familias nucleares con líderes de edad avanzada. Los jóvenes no priorizan la conservación de los maíces locales sino actividades más rentables como la ganadería, los maíces híbridos y el café. Existe un excesivo uso de agroquímicos que afecta los recursos suelo, agua y biodiversidad. Se distinguieron 6 tipos de UPF de acuerdo con sus capitales humano y social. El grupo 3 (G3) mostró un mejor equilibrio entre ambos por la participación familiar, destacándose entre los de mayor experiencia en el cultivo de maíces locales y por tener relaciones locales y de cooperación más sólidas. Se concluye que las UPF presentan características que contribuyen o afectan la conservación de los maíces locales, como la continuidad generacional, el deterioro de los recursos naturales que sostienen el cultivo a través de la fusión de las prácticas tradicionales con las modernas y la dependencia de recursos externos.

Abstract The Family Production Units (FPU) are made up of natural, physical, financial, human and social capital. The last two constitute the basis for the functioning of the rest of the capitals and of the production unit. In Mexico, Chiapas and La Frailesca, the production of corn, and particularly local corn, has cultural, agronomic, and economic value. The objective of this research was to characterize the UPF that cultivate local corn, in the Frailesca region of the State of Chiapas, on the cultural basis of the management of human and social capital. 80 UPF from 20 communities were studied, selected through network sampling. The Sustainable Livelihoods approach was used as a frame of reference. Semi-structured interviews were applied, and participant observations were made. In the predominant study in nuclear families with elderly leaders predominated. Young people do not prioritize the conservation of local corn, but rather more profitable activities such as livestock, hybrid corn and coffee. There is an excessive use of agrochemicals that affects soil, water and biodiversity resources. Six types of UPF were distinguished according to their human and social capital. The third category (G3) shows a better balance between human and social capital due to their family involvement, standingout among those with more experience in growing local corn and having stronger local relationships. It is concluded that the UPF present characteristics that foster or impair the preservation of local corn such as generational continuity, the deterioration of the natural resources that sustain the cultivation through the fusion of traditional and modern practices and dependence on external resources.

Efecto de inoculantes y aditivos sobre fracciones de fermentación ruminal y degradación in vitro en ensilaje de sorgo (Sorghum sp) / Effect of inoculants and additives on fractions of ruminal fermentation and in vitro degradation in sorghum silage (Sorghum sp)

Resumen La acción de inoculantes y aditivos sobre la composición química y degradación ruminal de la materia seca (MS) de ensilaje de sorgo ya ha sido reportada. Sin embargo, se desconoce el efecto que estos tienen sobre la actividad microbiana, y por lo tanto, sobre su potencial de asimilación a nivel ruminal. El objetivo de este estudio fue evaluar el efecto de la adición de inoculantes y aditivos en ensilaje de la planta completa de Sorghum sp. sobre las fracciones de fermentación ruminal y degradación in vitro. Se utilizó un diseño experimental completamente al azar, con 7 tratamientos (control, 3 inoculantes, 2 aditivos y una combinación de inoculante con aditivo) y 21 repeticiones por tratamiento. Se usaron diferentes tipos de inoculantes y aditivos en el proceso de ensilaje de sorgo: lactosuero, yogur, ácido fosfórico, Lactobacillus plantarum y mezcla mineral. Después de 60 d de fermentación, se cuantificaron MS, pH, proteína cruda (PC), degradación in vitro de la MS a 24 h (DIVMS), parámetros de la cinética de fermentación (Vmáx = volumen máximo, L = fase lag, S = tasa de fermentación) y volumen fraccional (fermentación rápida = 0 h a 8 h, media = 8 h a 24 h y lenta = 24 h a 72 h) por producción de gas in vitro. El análisis estadístico indicó que los inoculantes y aditivos modificaron la composición química, los parámetros L, Vmáx, DIVMS y las fracciones de fermentación rápida y media (P < 0.05). El uso de lactosuero y L. plantarum como inoculantes en ensilaje de sorgo redujo la pérdida de PC y, en general, los inoculantes y aditivos mejoraron el pH de los ensilajes; no obstante, disminuyeron el aprovechamiento de las fracciones de fermentación rápida y media, modificaron el potencial de fermentación y provocaron efecto negativo en la DIVMS.

Abstract The action of inoculants and additives on the chemical composition and ruminal degradation of sorghum silage dry matter (DM) has already been reported. However, the effect that these have on the microbial activity and, therefore, on its potential for assimilation at the ruminal level is unknown. For that reason, the objective of this study was to evaluate the effect of the addition of inoculants and additisves in silage of the entire plant of Sorghum sp. on fractions of ruminal fermentation and in vitro degradation. The experimental design was completely random, with 7 treatments (3 inoculants, 2 additives and a combination of inoculate with additive) and 21 repetitions per treatment. Different types of inoculants and additives were used in the process of sorghum silage: cheese whey, yogurt, phosphoric acid, Lactobacillus plantarum and mineral mixture. After 60 d of fermentation, dry matter (DM), hydrogen potential (Hp), crude protein (CP), in vitro dry matter degradation to 24 h (IVDMD), parameters of fermentation kinetics (Vmax= maximum volume L = lag phase, S = fermentation rate) and fractional volume (rapid fermentation = 0 h to 8 h, intermediate = 8 h to 24 h and slow = 24 h to 72 h) were quantified through the in vitro gas production technique. The results indicated that the inoculants and additives modified the chemical composition, the L parameters, Vmax, IVDMD and the rapid and intermediate fermentation fractions (P < 0.05). The use of cheese whey and L. plantarum as inoculants in sorghum silage reduced the loss of CP. Overall, the use of inoculants and additives improved silage Hp; however, it decreased the use of rapid and intermediate fermentation fractions, modified the fermentation potential of the silage and provoked a negative effect on the IVDMD.

Traditional Knowledge of Edible Wild Plants Used by Indigenous Communities in Zongolica, Mexico.

Edible wild plants (EWP) continue to be an important food source for indigenous communities. A survey was conducted to identify the consumption and management of EWP known as quelites in the Zongolica region of Mexico. 15 species of quelites are consumed mainly during the rainy season, whose local name is associated with the plant's shape, smell and flavor. Changes in food patterns and land use threaten the permanence and consumption of these species. Indigenous and local knowledge is crucial for the use, management and conservation of this group of plants, whose consumption can be leveraged to address malnutrition and unhealthy food use.

Criterios campesinos para la selección de maíz (Zea mays L.) en Villaflores y Villa Corzo, Chiapas, México / Farmers' criteria for maize (Zea maysL.) selection in Villaflores and Villa Corzo, Chiapas, Mexico

RESUMEN La producción de maíz en Chiapas implica la decisión de cultivar maíces locales o híbridos. Estos últimos, tienen rendimientos más altos, pero requieren mayor cantidad de insumos, asociados con la degradación de suelos, contaminación del agua, pérdida de diversidad genética y del conocimiento sobre las variedades locales. El objetivo de esta investigación fue identificar los criterios que usan los pequeños productores, en la selección del material genético, para la siembra de maíz en los municipios de Villaflores y Villa Corzo, Chiapas. Se realizaron entrevistas semi-estructuradas a productores participantes del programa ASERCA. El maíz híbrido presentó mayor preferencia en ambos municipios, aunque algunos productores prefirieron los maíces locales o cultivaron ambos, por razones de usos y costumbres. La selección de maíces híbridos en los dos municipios se hizo principalmente con base en el rendimiento, seguido de la mayor resistencia a plagas y enfermedades. Otros criterios empleados para elegir semillas híbridas fueron: mayor resistencia al acame, mayor resistencia a la humedad, menor altura a la planta, menor pudrición de semillas y mayor tolerancia a la sequía. En maíces locales, el rendimiento fue un parámetro de importancia en ambos municipios, pero la mayor resistencia a plagas y enfermedades fue solo considerada en Villa Corzo. Y el mejor precio de venta del grano no se consideró en ninguno de los dos municipios. Otros criterios empleados para seleccionar las semillas locales fueron: mayor tolerancia a la sequía, menor costo de la semilla, mayor tamaño de la mazorca, interés por conservar dicho material, mejor sabor y permitir la rotación de variedades locales. Las seis características deseables a mejorar en el maíz local fueron: una menor altura de planta, un mayor rendimiento, una mayor resistencia a la humedad y al acame, un mayor peso del grano, un mayor tamaño de mazorca y de granos.

ABSTRACT The maize production in Chiapas implies the decision to grow local or hybrid maize. The latter present higher yields characteristics, but demand more inputs, particularly those related to soil degradation, water pollution, genetic diversity and knowledge losses over local maize varieties. The objective of this research was to identify the criteria used by small maize farmers in the election of seed for sowing in the Villaflores and Villa Corzo municipalities (Chiapas). The data were gathered through semi-structured interviews with farmers' participating in the ASERCA program and analyzed by percentages and frequencies. The hybrid maize is the most preferred variety by the small farmers in both municipalities, although some still prefer local maize (native) or bet on the cultivation of both due to use and customs reasons. The selectionof hybrid maizeseeds in both municipalities is based mainly on better yield characteristics, although in Villa Corzo, the selection of local varieties is due to their better resistance against pests and diseases. Additional criteria used to select the local seeds were: better lodging resistance, better moisture resistance, lower plant height, less seed rot and better drought tolerance. In local maize varieties, seed yield was considered an important factor in both municipalities, but a greater resistance against pests and diseases was only considered in Villa Corzo. The highest sale price was not an important consideration in neither of the two municipalities. Other criteria used to select the local seeds were better drought tolerance, seed lower cost, greater ear size, personal interest in conserving the local resource, better flavor and the possibility for the rotation of local varieties. The six wished characteristics of local maize varieties to be improved were: a lower plant height, a better yield, a better resistance to humidity and lodging, a greater grain weight, and a bigger size of ears and grains.