Abstract:
Reliable drinking water sources that meet minimum quality standards are essential for successful livestock production. Recent surveys have shown that many water sources, especially throughout the semi-arid rangelands of the U.S., are not of sufficient quality to support optimum herd/flock health and performance, in particular because of high concentrations of sulfur (S) and S-compounds present in the water. High S concentrations in water sources can arise from several factors. First, water sources can be naturally high in S. Second, drought conditions can cause S to be concentrated within the water source. Third, conventional oil and gas production can also increase S content within the water source. Combinations of these conditions can further exacerbate S levels in the water. Many of these water sources are used for livestock production systems, especially throughout the western states. However, high- water is associated with poor performance and health in ruminant livestock, and is a primary cause of polioencephalomalacia (PEM), a disease state that can cause 25% morbidity and 25-50% mortality in affected populations. Unfortunately, producers are typically limited in available water resources and cannot avoid high S water situations; there are also no practical means of treating high S water. Although no effective treatments are currently available for animals suffering from the effects of high dietary S, it has been noted that animals vary in their response to elevated levels of S. While some animals consuming high S water exhibit reduced performance and/or poor health, others appear unaffected. We hypothesize that differences in rumen microbial populations, which are responsible for the breakdown of S and S-compounds, are associated with the variation in animal response to high S. Therefore, in this study we aim to 1) determine how rumen microbial populations change in response to high S water, and 2) determine if the extent of those changes are associated with tolerance to high S. A better understanding of the rumen microbial response to high S will lead to development of treatments for affected animals.