Abstract The accumulation of greenhouse gases in the Earth's atmosphere is causing an unprecedented climate change with serious implications, such as extreme weather events and changes in the function and composition of ecosystems. Due to its importance it is relevant to analyze the impact of climate change on livestock systems. An area that requires special attention is precisely animal health, the emergence and re-emergence of vector-borne diseases in numerous regions of the planet are a clear example of the association between climate change and its effects on the human/animal health interface. The effects on health animal can obey multiple social and environmental factors causing the so-called "diseases of production", which influence the appearance of emerging diseases. However, each region and each livestock system has its own vulnerabilities. These aspects must be taken into account for the design of local and regional risk maps, as well as for the efficient design, implementation and socialization of risk management processes for diseases.

Resumen La acumulación de gases de efecto invernadero en la atmósfera terrestre está ocasionando un cambio climático con graves implicaciones, como fenómenos meteorológicos extremos, cambios en la función y composición de los ecosistemas. Debido a su importancia, resulta relevante analizar el impacto del cambio climático en los sistemas de producción pecuarios. Un área que requiere especial atención es precisamente la salud animal, la emergencia y reemergencia de enfermedades vectoriales en numerosas regiones del planeta constituye un claro ejemplo de asociación entre cambio climático y efectos sobre la interfaz de la salud humana/animal. Dichas afectaciones a la salud animal pueden obedecer a múltiples factores sociales y medioambientales, provocando las llamadas “enfermedades de la producción”, los cuales influencian la aparición de enfermedades emergentes. Sin embargo, cada región y cada sistema de producción tiene sus propias vulnerabilidades. Estos aspectos deben tomarse en cuenta para diseñar mapas de riesgos locales y regionales; así como diseñar, instrumentar y socializar eficientemente procesos de manejo de riesgos ante enfermedades.

Mechanical maceration enhances site and extent of digestion of low-moisture, low-quality forages. Four Holstein steers (172 ± 8 kg) with cannulas in rumen and proximal duodenum were used in 4x4 Latin square design to evaluate the process of mechanical maceration of sudangrass hay on the characteristics of ruminal and total tract digestion. Treatments consisted of a steam-flaked corn-based growing diet supplemented with 21 % forage (DM basis) as: i) wheat straw (Triticum aestivum, STRW), ii) sudangrass hay (Sorghum sudanense, SG), iii) macerated SG at intensity of 4,134 kPa (MAC600) and 4) macerated SG at intensity of 6,200 kPa (MAC900). All forages were ground to pass through a 3.8 cm screen before incorporation into complete mixed diets (21:79 forage to concentrate ratio). Maceration did not affect (p ≥ 0.17) on site and extent of OM, N and ADF, and DE of sudangrass supplemented diets. Characteristics of ruminal digestion of OM, ADF, starch, as well as, microbial efficiency (microbial N, g kg-1 of OM fermentad) and protein efficiency (nonammonia N, g g-1 of N intake) were not different (p ≥ 0.11) for wheat straw versus sudangrass supplemented diets. However, total tract digestion of OM, ADF, N, and DE diet were greater (p ≤ 0.05) for sudangrass than for wheat straw supplemented diets. Using the replacement technique, DE value of SG averaged 9.59 MJ kg-1, very close to the expected value given its chemical composition. Mechanical maceration did not enhance the feeding value of sudangrass hay. Increase the intensity of maceration from 4,134 to 6,200 kPa did not altered ruminal or total tract digestion of OM, NDF or energy value of processed hay