The objective of this study was to evaluate effects of dietary levels of neutral detergent fiber (NDF) on
feed intake, nutrients digestibility, rumen parameters and nitrogen retention of crossbred beef cattle (Black Angus ×
Zebu crossbred). Four male cattle at 17.5±1.78 (Mean±SD) months of age with an average live weight of 262±20.5
kg (Mean±SD) was allocated in a 4x4 Latin square design. The treatments were 47, 51, 55 and 59% NDF in diets
corresponding to NDF47, NDF51, NDF55 and NDF59 treatments following the previous findings of the in vitro
experiment. Each experimental period was two weeks including one week for adaptation and another one for sampling.
The results showed that nutrient intakes (kg/animal/day) were similar (P>0.05) among treatments, however DM and
OM intakes were numerically higher for the NDF55 treatment compared with the others. Digestibilities (%) of DM
and OM were significantly different (Phowever these values between NDF51 and NDF55 were not significantly different (P>0.05). Rumen pH, N-NH3,
and VFAs concentration values before (0h) and 3h after feeding were similar (P>0.05) among treatments. Nitrogen
retention value was numerically higher in NDF47, NDF51 and NDF55 treatments compared with NDF59 treatment
(P>0.05) and a similar trend of the observed daily weight gain was found in the treatments. It was concluded that
increasing levels of NDF in cattle diets from 47 to 59% reduced DM and OM digestibility while nitrogen retention
and daily weight gain decreased slightly. Content of 55% NDF in the diet could be properly recommended for further
study in terms of available forage utilization and daily weight gain.
Keywords | Neutral detergent fiber, Beef production, Digestion, Rumen ecology, Ruminants