Sunflower silage (SS) is being promoted as an efficient forage for feeding dairy cattle in the face of shortages of irrigation and erratic rainfall. The objective was to compare, through the in vitro gas production technique, the kinetics of ruminal fermentation of SS and its mixtures with maize silage (MzS) to know its nutritional characteristics before its inclusion in feeding strategies. Five combinations of SS with MzS were assessed (MzS%: SS%); T1) 100:0, T2) 75:25, T3) 50:50, T4) 25:75 y T5) 0:100. Combining MzS with 25% SS decreased neutral detergent fiber and acid detergent fiber contents (P<0.05), which resulted in a digestibility of dry mather, organic matter, neutral detergent fiber and metabolizable energy similar to MzS (P>0.05), and with a CP content not statistically higher than MzS. The MzS had the highest total gas production (GP) but at a lower fermentation rate (P<0.05) when compared to T2 that had a better fermentation rate of 0.0530 %/h, with Lag time of 3.4 h. Before ensiling, sunflower supplies 31.8 % more CP, 11.8 % less metabolizable energy and 11.9 % less in vitro digestibility of organic matter than maize plant. Compared to T1, the T2 supplied 1.6 % more crude protein, 2 % less metabolizable energy and 4.4 % less of in vitro digestibility of organic matter. Therefore it is concluded that sunflower silage could be an alternative to substitute up to 25 % of maize silage as the crude protein and metabolizable energy supply are similar to maize silage.

This paper has two objectives, the first is to determine the chemical composition, gas production parameters and the gas release kinetics, at different stages of maturity, of three grasses and a legume commonly found in long established pastures in (July, September and November 2003) and analysed using an in vitro gas production (GP) technique. The accumulated GP was fitted to the model described in PALMER et al. (2005)

Se evaluó el comportamiento productivo de bovinos doble propósito en un sistema silvopastoril intensivo (SSPi) en Apatzingán, Michoacán. La actividad se llevó a cabo mediante seguimiento técnico-económico. Asimismo, se monitorearon variables productivas y económicas (consumo de forraje, producción de leche, peso, ingresos y egresos) de 60 vacas de la raza Gyr analizadas mediante estadística descriptiva y presupuestos por actividad. La carga animal empleada fue de 2.06 UA ha-1 y la producción de leche obtenida fue 9.15 kg vaca-1 día-1. El manejo de vacas Gyr en un SSPi favorece la producción de leche y carne y el ingreso económico a la unidad de producción (UP).

Objective: Evaluate the physical-chemical properties and characterize the microstructure of four varieties of traditional Mexican chili (Capsicum annuum L.) powders: “Arbol”, “Guajillo”, “Piquin” and “Mole ranchero” (Ancho chili). Design/methodology/approach: Physical-chemical properties of chili powders were evaluated by means of moisture content, particle size, aerated and tapped bulk density, Carr index, Hausner ratio, angle of repose (flow properties), capsaicin, and carotenoids content. Microstructure of samples was characterized by Confocal Laser Scanning Microscopy and Scanning Electron Microscopy. ANOVA analysis and Tukey test were performed to evaluate the significant statistical difference between samples at 95% of confidence level. Results: “Arbol”, “Guajillo”, “Piquin” and “Mole Ranchero” chili powders presented a cohesive behavior respect to its flow properties related to aerated and tapped bulk density, angle of repose, Carr Index, and Hausner ratio values under moisture content between 6.59-14.48 gH2O/100g d.s. “Arbol” and “Piquin” chili powders presented the higher capsaicin content, while “Guajillo” and “Mole ranchero” showed the higher carotenoids content. FTIR spectra confirmed the presence of secondary amide, phenolic groups, alkanes, and aliphatic chains that belong to capsaicin structure at specific absorption bands. Microstructure of chili powders presented particles with surface imperfections as cracks and dents, and smooth surface that influence physical-chemical and flowability properties. Limitations on study/implications: Hight moisture content affect the physical-chemical properties, flowability and microstructure of traditional Mexican chili powders. Findings/conclusions: Moisture content between 6.59 and 14.48 gH2O/100g d.s. influences the physical-chemical properties, flowability and microstructure of traditional Mexican chili powders. To improve physical-chemical properties and flowability behavior of chili powders is required that moisture content be lower than 6.59 H2O/100g d.s.

Objective: Demonstrate the need to use locally generated data in the calibration of a near-infrared spectrometer (NIRS) in order to predict the chemical characteristics of fodder; instead of using data bases from other geographic regions, as is commonly done in Mexico. Design/Methodology/Approach: Two groups of samples collected in prairies of the central highlands of Mexico, the first group was used to calibrate the equipment; the equations generated were validated with a second group, collected in prairies that were different from the ones of the calibration group, but in the same geographic zone. Results: The best regression coefficients of the NIRS predictions, compared to traditional laboratory analyses were for crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), acid detergent lignin (ADL), dry matter (DM) and organic matter (OM) (0.93, 0.87, 0.87, 0.56, 0.72 y 0.68 respectively). The lowest predictive value was observed in ashes (0.27). Limitations of the study/implications: The results show the need to use local materials in the calibration process. Conclusions: NIRS will make predictions of their chemical composition, since this is influenced by geographic origin of the sample and its botanical composition

Objetivo: Evaluar el método de acondicionamiento y desinfección de Sagittaria macrophylla zucc. (Alismataceae) de la Cienega de Lerma, para su propagación y conservación. Diseño/ metodología/ aproximación: En el invernadero se estableció un diseño completamente al azar con tres repeticiones para evaluar dos tipos de sustrato para S. macrophylla, se evaluó el número y longitud de brotes sanos. El primer sustrato consistió en una mezcla de tierra negra y agrolita con una proporción de 2:1, respectivamente (S1); el segundo sustrato se consideró el control ya que consistió en sedimentos de la Ciénega del Rio Lerma (S2). Para evaluar un método de desinfección adecuado se estableció un diseño de bloques completos al azar en donde los tratamientos consistieron en: lavados+ etanol al 70%+ cloro comercial (T1) y lavados+ microdin-jabón líquido+ etanol al 70%+ cloro comercial (T2).  Las condiciones de fotoperiodo (luz y oscuridad) representaron los bloques del diseño experimental. Resultados: En el experimento de tipo de sustrato se obtuvieron diferencias estadísticas significativas (P<0.05) entre los tratamientos en donde S1 mostro 2.4±0.24 brotes en promedio con una longitud de 2.5 cm en 30 días y con tendencia a incrementar. En el experimento de desinfección se observaron diferencias estadísticas significativas (P<0.05), sin embargo el fotoperiodo no presento diferencias significativas (P>0.05). El T2 presento el menor porcentaje de contaminación 31.25%. Limitaciones del estudio/implicaciones: los resultados presentados son avances de un experimento a largo plazo. Hallazgos/conclusiones: El acondicionamiento de plantas madre de S. macrophylla es favorable en condiciones de invernadero en un sustrato compuesto por tierra negra y agrolita 2:1 permitiendo brotes nuevos y sanos. El mejor método de desinfección consistió en un enjuague a chorro de agua con jabón en polvo, 30 minutos con 100 ml de agua destilada más una gota de microdin comercial y dos de jabón líquido, dos minutos en agitación constante en etanol al 70% y 20 minutos en cloro comercial (6%) al 30% v/v, utilizando como explantes las yemas axilares de los tubérculos sin importar el fotoperiodo en el cuarto de incubación.

Respecto a las muestras de agua se obtuvo que solo el predio "La presa", en el municipio de Villa Guerrero, presenta un valor de pH superior a los límites de acuerdo a lo establecido en la Norma Oficial Mexicana NOM-127-SSA1-1994. En cuanto a la determinación de metales pesados en ambos sitios del muestreo se encontró presencia de Al, As, Cr, Cu, Pb y ZN, sin embargo los elementos con mayor concentración son el Al y Zn los cuales rebasan los límites permitidos. En las muestras de suelo, se encontró As, Cr, Cu y Pb con valores inferiores al límite permitido, sin embargo, al igual que en las muestras de agua, las presencia de Al y Zn fueron las de mayor concentración excediendo los límites permitidos por la norma.

Objective: The objective of this work was to analyze the viability and germination of Dichromanthus aurantiacus seeds, a terrestrial orchid from Toluca valley, México. Design/methodology/approach: The size and color were evaluated. Two methods determined the viability: 1) the tetrazolium test (imbibition for 24 hours in the water, 2 hours in calcium hypochlorite (CaCOCl2), and drops of Tween-80). 2) the asymbiotic seed germination by in vitro culture (imbibition for 24 hours in the water, and the concentration of MS medium plus natural extracts).   Results: The seeds of this specie showed approximately 0.2 mm long and 0.05 mm wide; they possess an embryo and a brownish testa. There were significant differences (P<0.05) between the treatments finding a positive effect with the tetrazolium test, achieving up to 91.4% viability. In the in vitro germination, the imbibition of the seeds favored contamination. The concentration of MS and the addition of natural extract presented significant differences (P<0.05), the 50% MS plus 10% of coconut water showed up to 92.8% of germination at 60 days. Study limitations/implications: The results are preliminary of a long-term experiment. Findings / Conclusions: The seeds of Dichromanthus aurantiacus showed brown testa and an oval embryo with dimensions of 0.2 mm long and 0.05 mm wide. The tetrazolium test’s viability showed 91.4% viability when they were soaked in sodium hypochlorite solution (CaCOCl2) for two hours, 24 hours soaking in tetrazolium solution (1%) plus two drops of Tween-80. The asymbiotic in vitro culture showed up to 92.8% germination in 60 days using MS medium at 50% enriched with 10% coconut water