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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

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.

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.

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.