Macro Mineral Content of Selected Tropical Dairy Cow Feedstuffs as a Basis for Dietary Cation–Anion Difference Calculation

Dietary cation–anion difference (DCAD) can be used as an instrument to regulate blood pH to optimize parathyroid hormone (PTH) function in regulating calcium (Ca) release from bone, increasing Ca absorption from the intestine, and Ca reabsorption from the kidney. Unfortunately, the data were limited for use in dairy cattle ration formulations. An attempt to analyze the macro minerals of selected tropical dairy cow feedstuffs as a basis for DCAD calculation has been made. The amounts of 232 feedstuffs consisted of grasses (n = 69), roughage (n = 52), and concentrate (n = 111) were collected from cattle central areas in West Java. The macro mineral contents of the feedstuffs, including Na, K, Cl, S, P, Ca, and Mg, were analyzed using an atomic absorption spectrophotometer, a spectrophotometer, or titration. The results showed that the average contents of Na, K, Cl, S, P, Ca, and Mg in roughages were 0.19%, 0.20%, 0.23%, 0.56%, 0.27%, 0.78%, and 0.19%, respectively, while for grasses, the values were 0.23%, 0.23%, 0.34%, 0.54%, 0.37%, 0.86%, and 0.18%, respectively, and for the concentrate, the macro mineral contents were 0.24%, 1.00%, 0.25%, 0.39%, 0.56%, 1.01%, and 0.21%, respectively. The DCAD calculation of the groups showed a tendency for acidic properties in the major grasses and roughage, while the concentrate tended to be alkaline. The macro mineral database provided by this research can be made available to farmers to adjust their ration DCAD during the transition period for better prevention of Ca drop in early lactation.