Relationship between occurrence of white diarrhea and changes of properties and components of blood and milk in their dams after parturition in Japanese Black calves.

We investigated the diet content and properties of blood and milk in 11 pairs of Japanese Black cows and their calves for the one month following delivery. Four pairs (group A) had been no cases of white diarrhea during the year prior to this study, and 7 pairs (group B) had been a high occurrence of white diarrhea in calves during the same period. Properties of dams' diet in groups A and B before the onset of white diarrhea in calves were as follows: TDN fullness rate 98 +/- 2% vs. 110 +/- 5%, DCP fullness rate 151 +/- 2% vs. 200 +/- 33%, and starch content 5 +/- 2% vs. 14 +/- 3%. Blood and milk samples were collected from cows weekly and at the onset of white diarrhea in calves. No calves in group A had white diarrhea, while 5 out of 7 calves in group B had the diarrhea in this study. All cows were fed mixed hay, but 3 out of 5 cows whose calves had white diarrhea had been additionally given 3.0-3.5 kg of corn-silage a day from 4-5 days before onset. In all cows in the white diarrhea development group, the fat content of milk increased by 2.94 +/- 1.82% at the day of onset in comparison before. Serum TG and BUN, respectively, increased by 3.8 +/- 1.3 mg/dl and 3.7 +/- 2.0 mg/dl. Feeding cows a low-starch diet and additional corn-silage may induce a transient increase in blood TG, BUN and milk fat, which may contribute to the occurrence of white diarrhea in calves.