Significance of Hypovolemia in Feed Intake Control of Goats Fed on Dry Feed

  • Sunagawa, Katsunori ;
  • Prasetiyono, Bambang W.H.E. ;
  • Shinjo, Akihisa
  • Received : 2001.01.10
  • Accepted : 2001.04.14
  • Published : 2001.09.01


The objective of this study was to examine the significance of feeding induced hypovolemia (decrease in plasma volume) in controlling the feed intake of goats fed on dry feed. In order to alleviate hypovolemia with feeding, a 2 h intravenous infusion (16-18 ml/min) of artificial saliva or mannitol solution was begun 1 h prior to feeding and continued until 1h after the start of the 2 h feeding period. In comparison with no infusion (NI), cumulative feed intake was increased by 41% with artificial saliva infusion (ASI) and by 45% with mannitol infusion (MI) by the completion of the 2 h feeding period. Both infusion treatments (ASI and MI) were significantly different (p<0.05) from the NI treatment in terms of the cumulative feed intake. The cumulative feed intake between the ASI and MI treatments was not significantly different (p>0.05). No infusion treatment (NI) had the lowest cumulative feed intake (929 g DM), whereas MI had the highest (1345 g DM), after completion of the 2 h feeding period. Generally, infusion treatments also increased the rate of eating at all time points after feeding was commenced. Following the first 30 mins of feeding, the rate of eating decreased sharply, and subsequently declined gradually in all treatments. Compared to the NI, both ASI and MI significantly (p<0.05) decreased thirst level (water intake for 30 mins after the completion of the 2 h feeding period) by approximately 13%. However, the thirst level caused by ASI and MI was not significantly different (p>0.05). Both ASI and MI decreased the plasma concentrations of osmolality and total protein, and hematocrit at 1 h after infusion. The results suggested that the thirst sensation in the brain could be produced by feeding induced hypovolemia. Moreover, the results indicate that hypovolemia is one of the factors controlling the feed intake of goats fed on dry feed.


Hypovolemia;Dry Feed;Feed Intake;Thirst;Goat