Four fistulated yearling male crossbred cattle calves (average body weight 176 kg) were fed on concentrate devoid of grain and wheat straw in approximately 1 : 1 ratio. The four concentrate mixtures were de-oiled rice bran with 0, 10, 20 and 30% molasses, respectively. To make the four concentrates iso-nitrogenous, groundnut cake was added at the rate of 0, 3, 6 and 9% respectively. The animals were fed in a 4 x 4 switch over design. Each feeding period lasted 4 weeks followed by rumen liquor collection. Dry matter intake was similar in all the groups. The level of molasses in concentrate mixture affected the volatile fatty acids (VFA) production and NH3-N. There was a non-significant increasing trend in the number of large holotrichs and decreasing trend in the number of small holotrichs with increase in the level of molasses in the concentrate mixture. The activities of carboxymethyl cellulase, alpha-amylase, xylanase and protease did not show definite patterns. The dry matter intake (DMI) and rumen fermentation pattern indicated that de-oiled rice bran with molasses upto 20% level can be a substitute for conventional concentrate mixture for maintenance. (C) 1999 Elsevier Science B.V. All rights reserved.
