Abstract
Fattening cattle were fed more than 1 kg of bark of needle-leaved trees, as a substitute for ricestraw, for a long time. As a result, many clumps and balls of bark fibers were formed with villi as nuclei in the rumen. They often induced pyloric obstruction, tympanites, and anorexia. In cattle fed raw bark of needle-leaved trees, chronic eosinophilic abomasitis and enteritis prevailed and there were a decrease in the number of protozoa (especially, large ones) harbored and the synthesis in the rumen and a fall in the rate of milk fat.
When bark feeding was suspended, clumps of bark fibers disappeared, but balls did not and villi remained in injured condition. The bark and the balls of bark fibers were particularly rich in ADF and ADF lignin. No marked changes were found in the color, odor, or quality of meat produced from the cattle involved.
