DRY MATTER DISAPPEARANCE OF ROUGHAGES IN NYLON BAGS SUSPENDED IN RUMEN

The nylon bag technique was used to determine the dry matter disappearance of six roughages varying in fiber content, and the effect of two hay diets and time in the rumen on digestibility. Values of alfalfa and Coastal Bermuda-grass obtained by this method were similar to published data obtained by conventional digestion trials, but dry matter disappearance for the higher fiber roughages of cottonseed hulls, corncobs, soybean straw, and corn stalks was considerably lower. Disappearance values were higher with the steer on Coastal Bermudagrass diet than on alfalfa-orchardgrass diet and were significant (P < .01) for all roughages except cottonseed hulls and corn stalks. For an average of all roughages, there was no increase in dry matter disappearance past the 72-hr period for both diets; however, a significant (P < .01) roughage × time interaction indicated that some roughages required a shorter time in the rumen than others to reach a maximum disappearance. © 1969, American Dairy Science Association. All rights reserved.