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Water Sources and Chemical Quality Considerations for Animal Production and Food Processing
This presentation will focus on the varying qualities of water required for livestock consumption and food processing operations; also to be discussed are implications for changes to water quality due to natural situations (e.g., drought), engineered water treatment, and industrial activity. Quantity and quality of water are the most critical dietary elements for livestock as water directly or indirectly effects physiologic processes. Chemical water quality parameters that are important for livestock and food processing include presence of macro minerals (e.g., total dissolved solids, hardness, sodium, calcium magnesium, chloride, nitrate, and sulfate), micro minerals (iron, copper, manganese, chromium, arsenic), presence of toxic chemicals (e.g., pesticides or cyanotoxins), and whether the water is required to meet standards established by the USEPA for Primary and/or Secondary Maximum Contaminant Levels. How drinking water can enhance or exceed nutritional needs will be presented through comparison of nutritional requirements for livestock and the corresponding data and variability for specific chemical parameters in ground and surface waters. For example, the macro nutrient sulfate and micro nutrient iron can either negatively affect either livestock health or the taste of meat and milk. Sulfate and iron concentrations vary widely in drinking water due to local geology as this controls which minerals are available to be dissolved into water. Another issue for livestock nutrition is its interplay with changing chemical water quality, as can be illustrated by total dissolved solids (TDS). TDS is the composite measure of all dissolved minerals and organics in water; it is an indicator of overall water quality that is readily measured. Guidance for livestock is that TDS should be at or below 1000 mg/L, with an upper limit of 2500 mg/L, and although higher levels can be tolerated for drinking, about 3000 mg/L can cause diarrhea. Drought conditions increase TDS, both because there is insufficient water to dilute natural TDS and due to water evaporation. TDS levels in the range of 3000 mg/L have occurred in the last few years and can negatively impact livestock health. Maintaining healthy livestock can be achieved through knowledge of which chemical parameters affect nutritional status, the natural occurrence of chemicals, plus regional and seasonal variability of water quality.
Keywords: water quality, nutrition, drinking water standards, minerals, livestock