Deforestation of tropical forests for the establishment of grass monoculture for livestock production is responsible for about 30 % of CO 2 emissions. This issue is particularly severe in degraded pastures because degraded soils favor CO 2 flow to the soil surface. Silvopastoral systems could reduce CO 2 emissions, notably by using live fences. Here, we hypothesized that live fences of Gliricidia sepium in livestock systems should reduce variations in environmental relative humidity and soil temperature and, in turn, reduce soil CO 2 emissions. Here, we studied two livestock systems: (1) grass monoculture of Brachiaria decumbens with live fences of G. sepium and (2) grass monoculture of B. decumbens without live fences. We measured soil CO 2 seasonal emissions at different times of the day, soil temperature, and environmental relative humidity. Nine 600-m 2 plots were established in each system. All variables were measured over four 6-h period during a 24-h period, twice a month from April to September. Our results show that soil CO 2 emissions showed less variability with G. septum live fences than without live fences. This lower variability is explained by the creation of a microclimate with a higher and more stable environmental relative humidity, provided by the shade of trees. Results also show, however, that global soil CO 2 emissions did not differ between the two systems, with and without live fence. Moreover, soil CO 2 emissions varied according to season, as shown by 1.082 g CO 2 m −2 h −1 in the wet season versus 0.871 g CO 2 m −2 h −1 in the dry season. Soil CO 2 emissions varied also according to sampling time, as shown by 1.116 g CO 2 m −2 h −1 in the night versus 0.960 CO 2 m −2 h −1 in the morning.

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The study aimed to evaluate the relationship between udder measurements and milk yield (MY) in dairy Pelibuey ewes. Udder measurements were taken twice a week for eight weeks before (initial) and after (final) milking, including udder depth (UD), udder circumference (UC), udder width (UW), teat length (TL) and teat diameter (TD) in 38 multiparous ewes. Additionally, udder volume (UV) and the difference (VDF) between initial UV (UVi) and final (UVf) was calculated as VDF = UVi − UVf. The MY varied from 0.10 kg/d to 1.04 kg/d, with a mean of 0.39 kg/d, ± 0.18 kg/d. Initial UC (UCi) ranged from 25.80 cm to 53.30 cm, and VDF varied from 1 cm3 to 2418 cm3. The TL and TD were not correlated with MY (p > 0.05), while UCi, UVi and VDF were positively correlated with MY (p < 0.0001; r = from 0.66 to 0.74). For the prediction of MY, the obtained equations had an r2 ranging from 0.54 to 0.63. The UCi, UDf, UWi and UWf were included in these models (p < 0.05). It is concluded that there was an acceptable correlation (r = 0.60) between the measurements of the udder, the volume of the udder and the daily milk yield in Pelibuey sheep. When direct measurements of milk production cannot be performed in practice, the measurement of udders and their volume could be a viable alternative to estimate milk yield production as an indirect method.

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T he purpose of this review is to discuss the role of agroforestry systems in providing environmental services, including more diverse and sustainable agricultural production, increased carbon stocks and enhanced biodiversity conservation, plus improved soil fertility, methane emission mitigation, and water and air quality. There is evidence that agroforestry systems have an important role in providing environmental services, as approximately 20 % of the world's population, primarily in rural and urban areas of developing countries, depends directly on agroforestry products. The adoption of agroforestry contributes to reduced greenhouse gas emissions (carbon dioxide and methane), diminishes the pressure on vulnerable ecosystems, and improves the livelihoods of rural communities.Resumen E l propósito de esta revisión es discutir el papel de los sistemas agroforestales en la prestación de servicios ambientales, incluyendo producción agrícola más diversificada y sostenible, aumento de reservas de carbono, conservación de la biodiversidad, mejora de la fertilidad del suelo, mitigación de emisiones de metano y calidad del agua y aire. Existe evidencia de que los sistemas agroforestales juegan un papel importante en la prestación de servicios ambientales, ya que aproximadamente 20 % de la población mundial, sobre todo las zonas rurales y urbanas de los países en desarrollo, depende directamente de los productos agroforestales. La adopción de sistemas agroforestales contribuye a reducir las emisiones de gases de efecto invernadero (dióxido de carbono y metano), disminuye la presión sobre los ecosistemas vulnerables y mejora las condiciones de vida de las comunidades rurales. Palabras clave:Biodiversidad, captura de carbono, emisiones de metano, fertilidad del suelo, conservación del agua.