2007 Volume 60 Issue 4 Pages 269-274
To determine the causative factors for milk fever, the dietary cation-anion difference (DCAD) during a closeup period, the blood level and the urine excretion rate of calcium were examined in periparturient cows, in a herd with high milk fever incidence (A; n=6) and a herd with no milk fever incidence (B; n=6). DCAD was lower in herd A (14.0mEq/100g) compared with the level in herd B (23.2mEq/100g). Cows in herd A showed lower levels of blood calcium (7.63mg/dl) on the day of calving and magnesium around parturition compared with those in herd B. There were no differences between the two herds in terms of blood phosphorus, sodium, potassium and chloride levels. Urine calcium and magnesium excretion rates were almost identical in both herds, whereas the magnesium excretion rate three days before and urine pH four days before calving were lower in herd A than they were in herd B. The present data, revealing lower DCAD in the close-up diet and lower blood calcium values in parturient cows of the herd with a high incidence of milk fever, suggests that factors other than DCAD such as calcium content in the diet may play an important role in preventing milk fever.
