A COMPARATIVE-STUDY ON RUMEN FERMENTATION OF ENERGY SUPPLEMENTS INVITRO

The possibilities of using an in vitro method with rumen inoculum (MENKE et al. 1979) were tested for measuring rates of fermentation in wheat, barley, maize, tapioca, sorghum, oat, rye, concentrate mixture, hay, and oat straw. The incubations were continued for 96 hours with recording of gas production at different time intervals. The rate of fermentation (k) was estimated by means of nonlinear regression procedure, with and without incorporation of lag time in the model. Estimates of k with and without lag time for the feedstuffs studied varied from 0.024 to 0.140 and 0.035 to 0.135 respectively. Problems regarding estimation and interpretation of lag time and its influence on k estimates are discussed. Application of k values and lag time for predicting ruminal digestion of organic matter is also discussed.