FILL EFFECT OF CONCENTRATES IN THE RUMEN OF SHEEP

In an experiment based on a 4 x 4 latin square design with eight sheep , of which four were fistulated, the effects of four diets (H: hay alo ne; HB: hay + barley; HW: hay + wheat; HP: hay + beet pulp) were studi ed on daily dry matter (DM) intake, rumen content and the physicochemi cal characteristics of rumen content. The supplies of 700 g of concent rate were equivalent, on average, to 32% of total DM intake of the die ts. Intake of hay alone was 66 g/kgW(0.75) and the rates of substituti on of roughage by concentrate were 0.48, 0.42 and 0.63 for diets HB, H W and HP, respectively. At the end of the main meal, fresh digesta con tents in the rumen were the same with all the diets, consistent with a physical effect on intake. The estimated residence times of the diges tive residues of the concentrates were 8, 4 and 9 h, with the value fo r barley probably including an increase in residues from hay. At the e nd of the night, rumen fill tended to be lower when animals were recei ving concentrates; thus, digestive residues of concentrates may not ha ve limited intake between large meals.