Significance of Feeding Induced Hypovolemia in Feed Intake Control of Goats Fed on Alfalfa Hay

  • Sunagawa, Katsunori (Faculty of Agriculture, University of the Ryukyus) ;
  • Prasetiyono, Bambang W.H.E. (Faculty of Animal Sciences, Diponegoro University) ;
  • Nagamine, Itsuki (Faculty of Agriculture, University of the Ryukyus)
  • Received : 2001.05.17
  • Accepted : 2001.11.19
  • Published : 2002.03.01


The objective of this study was to examine whether feeding induced hypovolemia (decrease in plasma volume) acts on the regulation of feed intake in goats fed on dry forage. In order to prevent feeding induced hypovolemia, a 2 h intravenous infusion (16-18 ml/min) of isotonic mannitol solution was begun 1 h prior to feeding and continued until 1 h after the start of the 2 h feeding period. The intravenous infusion of isotonic mannitol solution (MI) decreased plasma osmolality by 1.0%, plasma total protein concentration by 4.2% and hematocrit by 5.9%, respectively. In comparison with no infusion (NI), MI significantly decreased thirst level by approximately 13%. At the completion of the 2 h feeding period, cumulative feed intake had been increased by 43% by MI. In conclusion, feeding induced hypovolemia in goats fed on dry forage increased thirst level more than the increase in plasma osmolality did. The results demonstrate that feeding induced hypovolemia is one of the factors controlling feed intake in goats fed on dry forage.


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