Dietary cation-anion difference (DCAD) of forage species in Norway
2015
Nesheim, L., Norwegian Inst. for Agricultural and Environmental Research (Bioforsk), Stjoerdal (Norway) | Synnes, O.M., Norwegian Agricultural Extension Service, Aas (Norwegia) | Steen, A., Nordøyane Veterinary Office, Haramsøy (Norway) | Langerud, A., Norwegian Inst. for Agricultural and Environmental Research (Bioforsk), Stjoerdal (Norway)
The difference between cation and anion concentrations (DCAD) is an important property when assessing feed for dry cows in order to avoid hypocalcaemia following calving. Low values of DCAD may reduce the risk of milk fever. DCAD is often calculated as the difference between the cations Na+ and K+ and the anions Cl- and S2-. Research, particularly in Canada, has shown that chlorine fertilization may reduce DCAD, even to negative values, and that there might be differences in DCAD between commonly used grass species. In a research project in Central Norway the effect on DCAD of different rates of chlorine fertilizer application were investigated. Fertilization with 70, 140 or 210 kg Cl- per hectare in calcium chloride did significantly reduce DCAD in forage from leys dominated by timothy and meadow fescue. Pure stands of seven grass species were fertilized with either 0 or 140 kg Cl- per hectare in spring. The highest values of DCAD were found in perennial ryegrass and festulolium. Forage with low DCAD was given to dairy cows, and the pH in urine was measured to assess the risk of milk fever.
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