EFFECT OF DIETARY-COMPOSITION ON ABOMASAL AND DUODENAL MYOELECTRICAL ACTIVITY

The changes in the frequency of abomasal slow waves and their propagat ion, the abomasal spike burst rate and the duodenal spike burst rate w ere assessed in sheep fed three diets containing either 100 per cent c oncentrate, 50 per cent concentrate and 50 per cent forage, or 100 per cent forage. The frequency of abomasal slow waves and spike burst fre quency were both significantly reduced in sheep fed the diets high in concentrate when compared with animals fed the 100 per cent roughage d iet. The velocity of propagation of the slow waves and the duodenal sp ike burst frequency were not significantly affected by the dietary com position. The sheep consumed significantly less of the 100 per cent co ncentrate diet in the 45 minutes before recording than of the other tw o diets, but the amount of feed consumed was not correlated significan tly with the changes observed in the myoelectrical activity. These fin dings are consistent with an inhibitory effect of concentrate on aboma sal motility.