Effects of Ruminal Dosing of Mechanical Stimulating Brush and Feeding of Brewer’s Grains Silage on Methane Emission of Holstein Steer Fed High Concentrate Diet

Abstract

This experiment was conducted to determine the effects of ruminal dosing of mechanical stimulating brush (RF) and feeding of brewer’s grains silage on methane emission of steer fed high concentrate diet. Four Holstein steers (average weight : 698kg) were used as experimental animals. Brewer’s grains silage (BS), timothy hay (TH), rolled barley and soybean meal were used as experimental diets. The diet at maintenance level on metabolizable energy was fed twice a day in equal portion. Four treatments were set ; TH feeding, BS feeding, TH feeding with RF dosing and BS feeding with RF dosing. Steers were orally dosed with three RF per head. Results were as follows : 1) Dry matter (DM) digestibility decreased in BS feeding (P<0.01) in comparison with TH feeding but DM digestibility increased (P<0.05) when steers were dosed with RF. 2) No significant difference was observed on methane emission per kg digestible organic matter between BS and TH feedings, however, methane emission significantly decreased (P<0.01) in RF dosing. 3) There was no significant difference in pH and ammonia concentration of rumen fluids in all treatments. Protozoal number decreased (P<0.05) and propionic acid increased (P<0.05) 3 hours after feeding when steers were dosed with RF. 4) The ruminal passage rate on liquid and solid phases significantly increased (P<0.05) in RF dosing. These results showed that RF did not decrease digestibility but decreased methane emission, though BS had no effect on methane emission.