Influence of regimen (roughage vs. concentrates) on satiety and forestomach motility in sheep.

The influence of concentrate intake on the subsequent intake of hay was investigated in sheep fitted with a rumen cannula and electrodes on the reticulum wall to measure volatile fatty acids concentration and reticular motility, respectively. In sheep fasted during night time, a previous meal of concentrates given 30, 60 or 120 min before feeding hay, did not modify significantly (p less than 0.05) the first hour and the first 3 hour intake of hay despite a large increase in ruminal total volatile fatty acid concentration. However, the daily intake of hay was significantly (p less than 0.05) reduced. Similarly, the reticular motility in response to feeding hay was not affected by the previous meals of concentrate. It is concluded that in fasted sheep on a hay ration the short-term satiation of a hay meal is not affected by foregoing intake of concentrates and that the hay intake is not controlled by ruminal volatile fatty acid levels.