Relationship Between the Incidence of Displaced Abomasum and Feeding of Cows in Tokachi District, Hokkaido, Northern Japan

In order to investigate the relationship between the incidence of displaced abomasum and feeding, the actual feeding practices and chemical compositions of roughage were examined in 2 kinds of farms at Tokachi district in Hokkaido. Examination of animal health records revealed that the annual milk yield per cow in high incidence (H-DA) farms was significantly higher than that in low incidence (L-DA) farms. The amount of concentrates fed in H-DA farms tended to be higher than that in L-DA farms during lactation. Compared to L-DA farms, the amount of juicy roughage (corn silage and grass silage) and dry roughage (hay, hay cube and roll wrap silage) during lactation in H-DA farms tended to be higher and lower, respectively. Moreover, the amount of roughage and the ratio of roughage to concentrates in H-DA farms tended to be lower than in L-DA farms. The survey indicated that displaced abomasum was associated with insufficient feeding of dietary fiber and overfeeding of concentrates.