Evaluación bacteriana de queso artesanal Zacazonapan madurado bajo condiciones no controladas en dos épocas de producción

Traditional Zacazonapan cheeses have unique organoleptic characteristics and are characterized by being linked to the territory of origin. In the maturation process, there are many interactive variables that are responsible for physical, chemical, biological and structural changes. In order to evaluate the bacteriological evolution of artisanal cheeses during their maturation under non-controlled conditions in two production periods, samples of raw milk and cheese were collected at 0, 30, 60, 120 and 150 d of maturation. The presence of molds and yeasts (MaY), mesophilic aerobic bacteria (MAB), Staphylococcus spp. (Staph), total coliforms (TC), fecal coliforms (FC), Salmonella spp. (Salm) and Listeria spp. (List) was determined. The average microbial load was 9.68, 9.38, 8.55 and 8.10 log10 CFU/g of cheese for MaY, MAB, Staph and TC respectively, as well as 2.68 log10 MPN/g of cheese for FC. Salm was not detected but List was. The microbiological evolution of Zacazonapan matured cheese had counts that exceed the maximum levels of the Official Mexican Standard 243 SSA1 2010.Los quesos tradicionales Zacazonapan tienen características organolépticas únicas y se caracterizan por estar vinculados al territorio de origen. En el proceso de maduración se tienen numerosas variables interactivas que son responsables de los cambios físicos, químicos, biológicos y estructurales. Con el objetivo de evaluar la evolución bacteriológica de quesos artesanales durante su maduración bajo condiciones no controladas en dos épocas de producción, se colectaron muestras de leche cruda y de queso a los 0, 30, 60, 120 y 150 días de maduración. Se determinó la presencia de mohos y levaduras (MyL), bacterias mesófilas aerobias (BMA), Staphylococcus spp. (Staph), coliformes totales (CT), coliformes fecales (CF), Salmonella spp. (Salm) y Listeria spp. (List). La carga microbiana promedio fue 9.68, 9.38, 8.55 y 8.10 log10 UFC/g de queso para MyH, BMA, Staph y CT respectivamente, así como 2.68 log10 NMP/g de queso para CF. No se detectó Salm pero si List. La evolución microbiológica del queso madurado Zacazonapan presentó conteos que superan los niveles máximos de la Norma Oficial Mexicana 243 SSA1 2010

Weed control with small ruminants: Exploratory evaluation on Senecio inaequidens

Objective: Carry out an exploratory evaluation of sheep and goats grazing in a temperate pasture invaded by Senecio inaequidens, as a means of biological control of weeds in small-scale dairy systems (SSDS). Methodology: Crude protein (CP), neutral detergent fibre (NDF), and acid detergent fibre (ADF) were determined on pasture and Senecio samples. The effect of grazing by sheep and goats on the pasture was assessed by means of the height, density and soil cover of Senecio, and also sward height; and the live weight of the animals, daily weight gain and body condition score were recorded. Statistical analysis was by a 2x2 factorial design, with species (sheep or goat) and two grazing intensities at 28.3 or 50.3 m2/animal per day. Results: height, coverage and density of Senecio did not show significant differences (P>0.05), neither did sward height. The chemical composition of the pasture did not show statistically significant differences for the assessed periods either. Animal weight, body condition and daily weight gain did not show significant differences among the evaluated treatments (P>0.05). Implications: This is the first report evaluating sheep and goat grazing to control of Senecio invasion in temperate pasture in central Mexico. In addition, knowing the chemical quality of Senecio will allow decisions to be made for supplementation in grazing systems with sheep or goats. Conclusions: The grazing of sheep and goats reduced the number of Senecio plants in the assessed pasture, which indicates the possibility of controlling this weed by grazing sheep or goats over longer-term grazing.Objective: Carry out an exploratory evaluation of sheep and goats grazing in a temperate pasture invaded by Senecio inaequidens, as a means of biological control of weeds in small-scale dairy systems (SSDS). Methodology: Crude protein (CP), neutral detergent fibre (NDF), and acid detergent fibre (ADF) were determined on pasture and Senecio samples. The effect of grazing by sheep and goats on the pasture was assessed by means of the height, density and soil cover of Senecio, and also sward height; and the live weight of the animals, daily weight gain and body condition score were recorded. Statistical analysis was by a 2x2 factorial design, with species (sheep or goat) and two grazing intensities at 28.3 or 50.3 m2/animal per day. Results: height, coverage and density of Senecio did not show significant differences (P>0.05), neither did sward height. The chemical composition of the pasture did not show statistically significant differences for the assessed periods either. Animal weight, body condition and daily weight gain did not show significant differences among the evaluated treatments (P>0.05). Implications: This is the first report evaluating sheep and goat grazing to control of Senecio invasion in temperate pasture in central Mexico. In addition, knowing the chemical quality of Senecio will allow decisions to be made for supplementation in grazing systems with sheep or goats. Conclusions: The grazing of sheep and goats reduced the number of Senecio plants in the assessed pasture, which indicates the possibility of controlling this weed by grazing sheep or goats over longer-term grazin

Evaluation of energy supplements in dual purpose cows in a silvopastoral system

The objective was to evaluate the effect of three energy concentrates on dietary nitrogen utilisation efficiency, milk production and milk composition. Twelve dual-purpose cows fed in a silvopastoral (SSP) system with Leucaena leucocephala and Digitaria swazilandensis were fed four treatments, supplemented with 25 MJ/cow/day of sorghum, molasses and gluconeogenic precursors, plus the control treatment, using a 4×4 Latin square experimental design with three replicates and experimental periods of 14 days and a total duration of 56 days. No significant differences were found for milk yield, milk chemical composition and milk urea nitrogen (MUN). No significant differences were found for cow live weight and dry matter intake. Forage analysis showed significant difference for crude protein (CP) concentration. There was no significant difference for average values of dry matter (DM) yield, neutral detergent fibre (NDF), acid detergent fibre (ADF), lignin and in vitro DM matter. For Leucaena, a significant difference was found only in DM yield, with period 4 being the highest yielding period compared to periods 1, 2 and 3. There was no significant difference for CP, NDF, ADF, lignin and in vitro DM digestibility. This work allows to understand the interaction of CP metabolism with DM. It is concluded that SSP provides sufficient dietary energy to cows in production for dual-purpose cows ranching

Festulolium and annual ryegrass pastures associated with white clover for small-scale dairy systems in high valleys of Mexico

O Background: The implementation of polyphytic pastures composed of grasses and legumes is an important component of agricultural systems in temperate zones, since grazing pastures which can reduce feed costs— are a viable option for small-scale dairy systems (SSDS). Objective: To evaluate the continuous grazing of dairy cows in Festulolium pastures associated with annual and perennial ryegrass and with clover in two farmrs. Methodology: Two experiments were carried out. The first experiment was established in the municipality of Almoloya of Juárez using eight cows that were divided into two groups of four; the cows grazed on two pastures with Festulolium associated with annual ryegrass and they were fed with 3.6 kg DM/cow/day of commercial concentrate, for 16 weeks. The second experiment was carried out in the Northwest of State of Mexico; six multiparous cows grazed on two pastures, under a cross over design arrangement; one pasture features Festulolium cv Spring Green and the other, annual ryegrass. Milk and body condition ere measured every 3 and 12 d, respectively. Variables from both experiments were analyzed using a split-plot experimental design. Results: Neither experiment recorded significant differences for the net accumulation of forage, the height of the pastures, and their chemical composition (P>0.05). No significant differences between treatments (P>0.05) were recorded regarding the yields and chemical composition of the milk. Study Limitations/Implications: The study of mixed pastures can be an alternative for feeding grazing cows, helping to reduce costs in SSDS. Findings/Conclusions: Festulolium/annual ryegrass pastures with white clover are a viable forage alternative for small-scale dairy systems

Diagnóstico de la calidad sanitaria en las queserías artesanales del municipio de Zacazonapan, Estado de México

Objetivo. Determinar la prevalencia y el grado de contaminación por mohos y levaduras (M&L), bacterias mesófilas aerobias (BMA), coliformes totales (CT) y Salmonella spp. (S) como indicadores de calidad e higiene en el entorno de fabricación del queso de Zacazonapan. Material y métodos. En cinco queserías se obtuvieron muestras de agua, leche, cuajo y queso, y de superficie de las manos y de los utensilios que están en contacto con el queso. Resultados. Todas las superficies presentaron contaminación; por lo tanto, se observa falta de higiene al elaborar el queso. Los conteos durante la elaboración de queso fueron, para leche, de 6.8, 6.7 y 4.5 log10 UFC/ml para M&L, BMA y CT, respectivamente. En queso, se detectó la presencia de S y cuentas de 9.16, 9.23 y 9.18 log10 UFC/g para M&L, BMA y CT. Conclusiones. La poca higiene en queserías y utensilios al elaborar el queso representa un riesgo para la salud humana.   DOI: http://dx.doi.org/10.21149/spm.v58i4.802

Bioconstrucción para la vivienda. Pensamientos y técnicas

Este libro difunde el conocimiento sobre vivienda emanado de la actividad universitaria y busca promover la investigación sobre este objeto de estudio, en particular en el campo de la biotecnología. Los pensamientos y las técnicas aquí reportadas abonan a la visión alternativa de vivienda asociada a los valores y características de la comunidad en cuanto a sus formas de vida, su cosmovisión y sus recursos, todo ello con atención al uso de los recursos naturales y al cuidado del ambiente.El presente libro muestra varias propuestas para atender las necesidades de los sectores público, social y productivo con enfoques sustentables. Los procesos de indagación y aportes al conocimiento se caracterizan por favorecer la libertad en la conceptualización, de tal forma que el desarrollo de las actividades de investigación supone la ausencia de influencias ajenas que desvíen los principios universales de la ética y el profesionalismo universitario.Universidad Autónoma del Estado de México