0023-6152

AA00697606

1526394

Unrefereed

0023-6152

AA00697606

The objective of this study was to investigate the effects of rice straw, annual ryegrass straw, and Klein grass hay on ruminal disappearance characteristics and CH_4 emission in Hanwoo cows. Two Hanwoo cows (358±10.61 kg) fistulated at the rumen were treated with two replications of each treatment during the 63–day experimental period. In accordance with TDN (total digestible nutrients) of the Korean Feeding Standard for Hanwoo (NISA, 2007), concentrates and forage (6:4 ratio) were provided twice a day, with a free access to mineral block and water. Using the in situ method with a nylon bag, disappearance rates in the rumen of DM, CP, NDF, and ADF were measured. CH_4 emissions were measured hourly using a hood–type chamber. Disappearance rates in the rumen of DM, CP, NDF, and ADF were higher in Klein grass hay, rice straw, and annual ryegrass straw, in that order, with significantly higher (p<0.01) in Klein grass hay than in rice straw and annual ryegrass. The average hourly CH_4 emissions were as follows; annual ryegrass straw (169.89±6.94 mg/hr), rice straw (139.92±18.89 mg/hr), and Klein grass hay (128.20±4.91 mg/hr), significantly higher (p<0.01) in annual ryegrass straw than in Klein grass hay. These results suggest that rice straw is a useful feed resource for ruminant production, which is mostly utilized as a domestic feed. However, imported roughage such as annual ryegrass straw showed lower disappearance and higher CH_4 emission than rice straw.