Abstract
Oesophageal and rumen fistulated sheep (av. 30kg BW) were used to determine the changes of weight, dry matter content, digestibility and particle size distribution of regurgitated boli within a day. They were fed alfalfa hay cube for 2 hours once a day.
1) Total regurgitated bolus amount within a day was 3391g/ head ·day. 2) The bolus weight per regurgitation distributed between 5g and 80g although the most frequently observed bolus weight was 20g. 3) It was estimated that average weight of bolus per regurgitation was 1g/kg BW. 4) The dry matter content of regurgitated bolus was 7.4%.It decreased slightly as time lapsed after feeding. 5) The dry matter disappearance rate of the boli measured by nylon bag in vivo was 50.4%. No definite change was observed within a day. 6) Average particle size distribution of the boli was 14%, 42% and 44% in large (>1190 μm), small (1190-45μm) and soluble (<45μm) fractions, respectively. The large particle fraction decreased as time lapsed after feeding but the other two fractions almost remained unchanged. 7) The average of mean particle diameter of the boli was 635 μm with no exact difference between sampling time within a day.
