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, A.M. Dietrich of Virginia Tech explained here at the 2014 Joint Annual Meeting of the American Dairy Science Association and American Society of Animal Science in Kansas City.
For livestock, quantity and quality of water are the most critical dietary elements as water directly or indirectly affects physiologic processes. Dietrich explained that chemical water quality parameters that are important for livestock and food processing include presence of macrominerals (e.g., total dissolved solids, hardness, sodium, calcium, magnesium, chloride, nitrate, and sulfate), microminerals (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 EPA for Primary and/or Secondary Maximum Contaminant Levels.
Presented was a comparison of nutritional requirements for livestock and the corresponding data and variability for specific chemical parameters in ground and surface waters. Dietrich said the macronutrient sulfate and micronutrient 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, it was noted.
Another issue for livestock nutrition is its interplay with changing chemical water quality, as can be illustrated by total dissolved solids (TDS). Dietrich explained that total dissolved solids is the composite measure of all dissolved minerals and organics in water and 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.
Dietrich noted that drought conditions increase TDS, both because there is insufficient water to dilute natural TDS and due to water evaporation. Total dissolved solids levels in the range of 3000 mg/L have occurred in the last few years and can negatively impact livestock health.
For livestock, quantity and quality of water are the most critical dietary elements as water directly or indirectly affects physiologic processes. Dietrich explained that chemical water quality parameters that are important for livestock and food processing include presence of macrominerals (e.g., total dissolved solids, hardness, sodium, calcium, magnesium, chloride, nitrate, and sulfate), microminerals (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 EPA for Primary and/or Secondary Maximum Contaminant Levels.
Presented was a comparison of nutritional requirements for livestock and the corresponding data and variability for specific chemical parameters in ground and surface waters. Dietrich said the macronutrient sulfate and micronutrient 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, it was noted.
Another issue for livestock nutrition is its interplay with changing chemical water quality, as can be illustrated by total dissolved solids (TDS). Dietrich explained that total dissolved solids is the composite measure of all dissolved minerals and organics in water and 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.
Dietrich noted that drought conditions increase TDS, both because there is insufficient water to dilute natural TDS and due to water evaporation. Total dissolved solids levels in the range of 3000 mg/L have occurred in the last few years and can negatively impact livestock health.