SUMMARYThe small-scale dairy farms are challenged to produce milk in a specific quantity and quality that encourages greater consumer demand and an appropriate transformation into cheese, yoghurt and candy, ensuring profitability. A study to assess the quality of raw milk stored in containers without cooling system was carried out in 30 production units located in the south of Mexico City, according to the standard PROY-NOM-155-SCFI-2003. The production units were evaluated during three seasons (dry, rainy and winter) and classified by the type of procedures for cleaning the udder, before milking (traditional, full and partial). The results showed that the milk component (fat, protein, casein, pH, acidity and cryoscopic point) were different depending on the time of sampling (P < 0.05), as well as mesophilic bacteria and somatic cell count (CCS), while lactose, total solids, non fat solids, density and reductase time showed no change (P > 0.05). During winter, a deep cleaning produced lower CCS and higher reductase time (P < 0.05) compared to the dry and rainy seasons. In conclusion, the nutritional components and physicochemical parameters of raw milk in household production units are within the Mexican standard range for raw milk, but the hygienic quality is deficient resulting from inadequate milking practices.Palabras clave: leche cruda, calidad, prácticas de ordeño.

There is little information on the population status of the ocelot Leopardus pardalis in Mexico. In the Sierra Abra-Tanchipa Biosphere Reserve, in San Luis Potosí, ocelots are affected by habitat loss and fragmentation as a result of increased agricultural development. We used photographic identification in camera-trapping capture–recapture surveys to determine population abundance and density during the dry season and subsequent early and late humid seasons during April 2011–March 2012. We recorded 80 photographs of 15 individuals (10 males, one female, and four of undetermined sex) in 7,786 camera-days. Abundance was estimated using a closed capture heterogeneity model, yielding an estimated population of 9 ± SE 3 in the dry season and 21 ± SE 8 and 15 ± SE 5 during the subsequent early and late humid seasons, respectively. Spatially explicit density estimates were 0.04 and 0.03–0.18 individuals per km2 for the dry and humid seasons, respectively, and were similar (P > 0.612) among seasons. Peaks in ocelot activity occurred during 20.00–04.00. We conclude that the ocelots of the Sierra Abra-Tanchipa Reserve have a low population density and may face geographical and biological isolation as a result of habitat conversion. Continued monitoring and improved understanding of the movements and habitat preferences of ocelots are necessary to ensure their continued persistence, and connectivity between this population and others in north-east Mexico.

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40Genealogical records of animals (studbook) are created to avoid reproduction between closely 41 related individuals, which could cause inbreeding, particularly for such endangered species as

El objetivo de este estudio fue determinar las características productivas, indicadores económicos, índice de adopción de tecnología y la relación entre ellos, en unidades de producción en bovinos de doble propósito. La investigación se desarrolló en tres regiones del trópico mexicano (Tabasco, Chiapas y Sinaloa), en 30 unidades de producción del sistema doble propósito, elegidos con muestreo aleatorio, se estableció un sistema de registros que incluyó variables productivas, prácticas de manejo y erogaciones del proceso de producción. Con un análisis de varianza se detectaron diferencias en las variables productivas e indicadores económicos entre regiones y un análisis de regresión fue utilizado para medir la relación del índice de adopción tecnológica con las variables de desempeño económico. La producción promedio de leche por vaca y día fue de 6,47; 5,49 y 12,24 l; el índice de adopción tecnológica (con escala de 0 a 21) fue de 10,95; 9,20 y 12,24 y el coste de producción de un litro de leche fue de 0,24 €, 0,26 € y 0,28 € en Tabasco, Chiapas y Sinaloa, respectivamente, difiriendo entre regiones (P < 0,05). Los componentes tecnológicos más usados fueron en el área de alimentación, con frecuencias promedio de 97%, 93% y 100% y la frecuencia menor se presentó en el área de reproducción con 40%, 20% y 30% para Tabasco, Chiapas y Sinaloa, respectivamente. El índice de adopción tecnológica se relacionó positivamente con la producción de leche, la rentabilidad sobre la inversión y la utilidad.