Abstract
The nutritive values of dried fibrous residues prepared from oat and Italian ryegrass in the early heading stage were determined using sheep. As the control, a sun-cured hay prepared from Italian ryegrass at the heading stage was used. Each diet was given to the animals without any supplements as to provide 2.0-2.25% dry matter of their body weight per day. The digestibility of crude protein was not significantly different among the 3 diets and lower than those of the other components. Digestibilities of organic matter, nitrogen free extract (NFE) and energy were the highest in the hay and followed by the oat residue and the ryegrass residue in that order. The digestibility of crude fibre of the residues was higher than that of the hay. The amount of nitrogen retained by animals was not significantly different among the 3 dietary treatments. Ruminal ammonia concentration was the highest in sheep fed the oat residue and the lowest in those fed the ryegrass rasidue. Ruminal propionic acid concentration was significantly high in sheep fed the ryegrass residue. No significant differences were found in the levels of the other volatile fatty acid concentrations among the 3 dietary treatments. Haematocrit value, blood glucose level and blood urea level were the highest and plasma total protein level was the lowest in sheep fed the oat residue and these values were significantly different from those obtained on the hay. The sheep fed on the ryegrass residue was similar in haematocrit value and blood glucose level to those fed on the hay and in blood urea nitrogen level and plasma total protein level to those fed on the oat residue. From these results obtained in the present study, it can be concluded that the value of the dried fibrous residue used in this study as roughage for sheep was quite similar to that of sun-cured hay prepared from Italian ryegrass harvested at heading stage.
