Dietary cation-anion difference, also known as DCAD, is an important measure that is used when formulating diets for dry, transition and lactating dairy cows. The calculation for this measurement is based on the concentration levels of the cation minerals sodium (Na) and potassium (K), and the anion minerals chloride (Cl) and sulfur (S).
Cations are positively charged ions and when they are fed in the diet in a high concentration they promote an increase in blood pH levels making the blood alkaline. Whereas, anions are negatively charged ions and a diet that is higher in concentration in anions will promote a decrease in blood pH levels making the blood acidic.
A positive DCAD is beneficial for lactating dairy cows as it can help to increase milk production whereas a negative DCAD can be beneficial for transition cows as it can help prevent metabolic problems such as milk fever due to the cow being able to better mobilise stored Ca.
Feed Central offers a DCAD + NIR Feed Test for $166.5 incl GST. This test has a two week turn around time and when done in conjunction with the NIR Express Feed Test offers and excellent overview of your feed. If you want to maximise your efficiencies in your dairy cows then it is worth finding out what the nutritional content and DCAD of your feed is.