Abstract
This study was undertaken to clarify the relationship between heat treatment and changes in the amino acid composition of rumenbypassed protein by comparing the amino acid contents of feed protein between before and after ruminal exposures. Second cutting Italian ryegrass (Lolium multiflorum LAM.) dried at 40℃, 80℃ and 120℃ and ensiled at 20℃ and 60℃ was prepared, and described as dried materials and ensiled materials, respectively. Rumen-fistulated sheep were used to collect samples after 2 hr. and 6 hr. ruminal exposures by in situ nylon bag technique. 1. The Pro and Val contents of 40℃-, 80℃- and 120℃-dried materials significantly decreased after ruminal exposure. In case of ensiled materials after ruminal exposure, there were two types of amino acids, one was "decrease" and the other was "increase". The former was Pro and Val of 20℃- and 60℃-ensiled materials, the latter was Phe, Arg, Met, Leu, Ileu, Ala, Gly, Glu and His of 20℃-ensiled materials, Phe, Arg, Met, Leu, Ileu , His and Lys of 60℃-ensiled materials. 2. In materials dried and ensiled, the amino acid pattern similarities between materials before and after ruminal exposures showed low value, but those between materials after 2 hr. and 6 hr. ruminaI exposures showed high value. 3. Therefore, though the relationship between heat treatment and changes in the amino acid composition of the rumen-bypassed protein was not clarified, the difference in amino acid compositions of materials between before and after ruminal exposures was recognized. And it was suggested that the amino acid composition was different between feed protein and rumen-bypassed protein.
