Large areas of arid and semi-arid grasslands in Mexico are severely damaged. Large areas of high-risk rainfed crops have been abandoned. These problems are the result of constant overgrazing, extraction of firewood, overutilization of valuable species, fire and the practice of subsistence agriculture. The aim of this study was to measure the initial performance of the seedlings, as well as forage production and survival in the second year of nine Bouteloua curtipendula populations native to Mexico in comparison with El Reno, a commercial variety from the US. Plant development was visually estimated and dry matter (DM) production was estimated one year after the establishment. Survival was assessed at the end of the growing season in the following year. The experiment was carried out using a complet randomized blocks experimental design, and differences in vigor between genotypes were analyzed by a permutation test. Significant differences in DM production and plant establishment (P ≤ 0.05) were observed between genotypes. The US commercial variety was the least productive population, exhibiting less vigor during the first year than the rest of the genotypes evaluated. Large diversity in seedling establishment capacity, DM yield and survival was observed in the second year. The Mexican populations 241, NdeM-303, 47 and NdeM-5 were superior for plant establishment and DM production.

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The forest ecosystems of Mexico experience soil degradation mainly due to water erosion, which causes low vegetation regeneration. One of the strategies to diminish soil loss is through the construction of stone bunds (SB)—hand-made structures to trap sediment and store water for longer periods. However, little is known about their effects on pine establishment. The objectives of this study were to evaluate the effect of SB on the survival and growth of individual P. engelmannii Carr. specimens with respect to the distance of their planted. The study additionally sought to analyse how SB would affect changes in the production of aerial phytomass, herbaceous vegetation cover and soil characteristics in a reforested area of Durango State in north-central Mexico. Three treatments were evaluated by planting pine trees at three distances with respect to the SB: 80 cm upslope bund (UB), 80 cm downslope bund (DB) and between upper and lower bunds (BB). The variables analysed were the following: The survival and growth of reforestation, aerial coverage and the production of herbaceous plants, and the physicochemical characteristics of the soil. Survival showed significant differences (p < 0.05) among treatments, UB (80%), DB (27%) and BB (30%). The production of aerial phytomass did not show significant differences between treatments UB (1651 kg ha−1) and DB (1058 kg ha−1), although these two were different (p < 0.05) to BB (600 kg ha−1). On the other hand, the vegetation cover and soil characteristics did not show statistical differences. These results highlight the importance of the effect of SB on the survival of P. engelmannii Carr. and the growth of herbaceous vegetation.

Objetivo. Evaluar la composición química, contenido de compuestos fenólicos, cinética de producción de gas y emisiones de metano in vitro de siete especies vegetales con potencial alimenticio para alimentación de rumiantes. Materiales y métodos. Siete especies fueron evaluadas: encino gris (EG), encino rojo (ER), chicalote (CHIC), mezquite (MEZ), huizache (HUI), morera (MOR) y la estevia (STE). Los análisis de las muestras fueron: extracto etéreo (EE), cenizas (Cen), proteína cruda (PC), carbohidratos no estructurales (CNE), fibra en detergente neutro (FDN), fibra en detergente ácido (FDA), hemicelulosa, celulosa, lignina detergente ácida (LDA), taninos condensados (TC) y fenoles totales (FT), digestibilidad in vitro de la materia seca (DIVMS); así como las condiciones ruminales in vitro, producción de gas (PG), producción de metano y dióxido de carbono, nitrógeno amoniacal (N-NH3) y ácidos grasos volátiles (AGV´s). Resultados. Los resultados muestran que HUI, MEZ y MOR presentaron un mayor contenido de PC, las mayores digestibilidades (DIVMS) se observaron en CHIC, HUI y STE. De lo contrario, las producciones de metano más bajas fueron generadas por MEZ, ER Y HUI. Conclusiones. De acuerdo con los resultados en la composición química, CHIC, MOR y STE presentaron la mejor calidad nutricional ya que mostraron los más altos contenidos de proteína y una digestibilidad adecuada. Estos resultados sugieren que el uso de CHIC no afectaría las características nutricionales que ofrece un forraje de buena calidad. Además, las otras especies pueden usarse como aditivos o suplementos para alimentar a los rumiantes debido a su mayor contenido de proteína y taninos condensados.

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Uno de los principales objetivos de los productores pecuarios es mantener la calidad del forraje a niveles adecuados que permitan obtener una buena ganancia en producción de leche. Una estrategia de suplementación pueden ser los ensilados con fuentes de grasa y carbohidratos solubles que mejoren la calidad del forraje. El objetivo del presente estudio fue evaluar la calidad de fermentación y nutritiva del ensilado de avena con maíz molido y grano de girasol (SG), mediante tres combinaciones de forraje de avena y maíz molido (100-0, 95-5, 90-10) y tres niveles de grano de girasol (0, 5 y 10 %). Se determinó el pH, N-NH3, ácido láctico, así como materia seca (MS), proteína cruda (PC), grasa cruda (GC), carbohidratos no estructurales (CNE), digestibilidad in vitro de la materia seca (DIVMS), fibra detergente neutra (FDN), fibra detergente ácida (FDA) y lignina en los tratamientos por triplicado, empleando 27 microsilos. No se observó interacción significativa combinación × nivel de grano (P > 0.05). El contenido de MS fue mayor en T2 y la concentración de PC fue menor en T6 (95-5-10) (P ≤ 0.05). La interacción combinación × nivel de SG fue significativa para el contenido de GC, FDA, lignina y DIVMS (P ≤ 0.05); sin embargo, la interacción no fue significativa para pH y la concentración de FDN, N-NH3 y ácido láctico (P > 0.05). La inclusión de grano de girasol cuando se combina con forraje de avena y maíz molido aumenta el valor nutritivo del ensilaje de avena pero no mejora la calidad fermentativa del forraje.

Objective: To analyze the alternative sources of food for livestock production to mitigate greenhouse gas emissions in Mexico.Design/methodology/approach: A document archive analysis was carried out about the use of certain industrial and agricultural wastes in Mexico in the last decade, and how these can serve as an alternative source of animal feed; these offer certain chemical properties that promote the mitigation of greenhouse gas emissions in livestock systems and also generate an added value in the agricultural and industrial sector.Results: Agricultural and industrial production in Mexico generates an important amount of wastes that are not exploited; in parallel, livestock production in Mexico is growing exponentially, which demands a surface and consumption of natural resources. Therefore, agricultural and industrial residues in Mexico represent a potential alternative source of animal feed, which offers a reduction in the surface destined to the production of food for animals and gives an added value to the industrial and agricultural residues in the country.Study limitations/implications: The alternative sources of food adjust to the agricultural and industrial sectors.Findings/conclusions: The use of agricultural residues, industrial wastes, and other alternate sources of food is suggested as a sustainable alternative in the reduction of GHG in livestock systems and a contribution to the mitigation of climate change in Mexico.

Objective: To evaluate the physicochemical properties of an extruded feed using bean (Phaseolus vulgaris L.) as a soymeal substitute and to perform pig growth trials, evaluating nitrogen digestibility. Materials and methods: This research was divided into two stages, the first one consisted on the standardization of the extruded feed, where two formulations of bean flour (Pinto Saltillo variety), cornflour (Cafime variety), and soybean meal were evaluated: 20/67/13% and 30/60/10%, respectively. Samples were processed in a single screw extruder at 120-150°C and moisture content of 18-22%. Evaluated physicochemical properties were: expansion index, bulk density, water absorption index, water solubility index, hardness, water activity and color parameters: L*(clarity), a*(red-green chromaticity) and b* (yellow/blue chromaticity). In the second stage, the in vitro dry matter digestibility and fecal apparent digestibility were evaluated using the optimal treatment obtained from stage 1. Results:  Optimal conditions for the 20% of bean flour formulation were: Temperature of 124.4°C and moisture content of 18.59%. Extrusion temperature decreased bulk density, hardness, and water activity, but increased L* and expansion index. Moisture content decreased bulk density, water activity, hardness, and a*. In vitro dry matter digestibility was higher for the extruded bean diet in comparison to the control diet (92.33% vs. 85.33%). Conclusions: Results indicated that bean flour is a viable option for animal consumption in terms of nutritional value and good digestibility.