The effect of crude fiber content in diets on ruminating behavior of sheep was investigated.
In experiment 1, two sheep (Av. B. W. 44kg) were used to compare the ruminating behavior when fed Italian ryegrass (crude fiber : 33.5% on D. M. basis) with when fed ladino clover (20.3%), in fresh material. In experiment 2, another two sheep (av. B. W. 37kg) were used to compare Hay I (crude fiber : 32.6% on D. M. basis) with Hay II (25.7%). In each experiment, sheep were fed about 2% of B. W, of experimental diet in D. M. basis, in two meals daily. Following a 6-day preliminary feeding of each diet, ruminating behavior was observed during two consecutive days.
In both experiments, when sheep were fed the diet containing less crude fiber, ruminating time and number of chews markedly decreased, and chews per bolus also lessened. Ruminating time or number of chews per unit of dry matter ingested decreased with lower crude fiber content in the diets, in each of two experiments. However, these values which were showed as per unit of crude fiber ingested became greater with lower digestibility of crude fiber in the diets. The longest ruminating time or the largest number of chews per unit of crude fiber ingested was obtained with legume diet (ladino clover), which showed the lowest digestibility for crude fiber of diets used in these experiments.