THE INFLUENCE OF THE POSITION IN THE RUMEN ON DRY-MATTER DISAPPEARANCE FROM NYLON BAGS

The dry matter disappearance was measured from either barley straw or rye grass hay incubated in the rumen in nylon bags attached to cords, with a distance of 25, 40, 75 or 105 cm from the rumen cannulae. The experiment was performed using two different feeding conditions, and on one of these the concentrations of ATP were measured both inside the bags and in the rumen content close to the bags. The results showed that an increasing cord length increased the dry matter disappearance from the bags as well as the microbial activities in the nylon bags, the latter expressed by the ATP concentration. The dry matter disappearance depends on the microbial activities, but is apparently also influenced by the extended mobilities of the bags obtained using increased cord lengths. The effect of the cord lengths should be taken into account when experiments involving feed evaluations with nylon bags are planned. © 1990, Taylor & Francis Group, LLC. All rights reserved.