2020 Volume 91 Issue 3 Pages 207-215
The current study was conducted to clarify the effect of replacing steam-flaked corn in fermented total mixed rations (TMR) with crushed brown rice as an alternative feedstuff on ruminal fermentation characteristics, plasma metabolites and nitrogen (N) utility in Holstein heifers. Four Holstein heifers (average 12.3 months old) were used in a crossover design study with two dietary treatments : an ensiled TMR containing 25% (dry matter basis) steam-flaked corn (corn TMR group) and an ensiled TMR containing 25% (dry matter basis) crushed brown rice (rice TMR group). Non-fibrous carbohydrate (NFC) digestibility was higher (P<0.05) in the rice TMR group than in the corn TMR group, while the digestibility of neutral detergent fibers with heat-stable α-amylase (aNDFom) tended to be lower (P<0.1) in the rice TMR group than in the corn TMR group. No remarkable differences were observed in ruminal fermentation or plasma metabolites between the two groups. Urine N excretion was lower (P<0.05) in the rice TMR group than in the corn TMR group. These results show that steam-flaked corn at a content level of 25% (dry matter basis) in the TMR can be replaced with the same amount of crushed brown rice without remarkable physiological influence on Holstein heifers.
