The Next Frontier in Nutritional Modeling and Ration Formulation-Water

Water is the most important nutrient to livestock and is often overlooked when evaluating livestock nutrient requirements and troubleshooting performance problems on the livestock operation. Water soluble nutrients and quality can vary dramatically from one livestock operation to the next, as well as, vary dramatically from one area of the country to another. In some cases, water can make a significant contribution to meeting the nutrient requirements of the animal, while in other situations, nutrient concentrations must be increased to offset the lack of nutrient supply via the water. Historically, nutrients supplied by water were not factored into the nutrient requirements of livestock, i.e. Nutrient Requirement of Livestock Species published by the National Research Council (NRC). Some nutritional models are starting to factor in this supply, via the use of prediction equations of water consumption and water nutrient composition, but this area is in its infancy. Water quality and quantity can be huge issues when selecting sites for building a new dairy operation. Issues, such as mineral concentrations, nitrates, bacteria, agronomic chemicals, along with the supply volume and flow rates are just some of the issues to address when siting a new dairy operation. Several water treatment systems are commercially available to address some of these concerns, which can range from inexpensive to very expensive depending on the nature of the water issue to be solved. There is limited research information available in this area, which could ensure this being a future productive area of research. Our work has shown that the use of laboratory distilled water compared to livestock operation water supply and water treatment systems had an impact on the rate and extent of ruminal digestion using an invitro gas production system. Therefore, the accuracy and precision of laboratory measurements combined with nutritional modeling and ration formulation for actual livestock performance can be influence by the quality and nutrient supply of the water source. This may explain the lack of agreement between predicted and actual livestock performance via nutritional models, especially dry matter intake. These areas will be discussed in more depth using livestock applications and implications.