Abstract
Fresh and wilted Italian ryegrass samples were ensiled at a heavy (unit quantity of 600kg/m^3, …H) or light (unit quantity of 300kg/m^3, …L) compaction level respectively and resultant silages (two high moisture and two wilted ones) were fed to castrated male goats in order to compare the digestibility and efficiency of nitrogen utilization between silages made at different compaction levels. The chemical quality of silage was exceedingly higher for the (H) in a high moisture silage, but there was little difference in quality between the (H) and (L) in a wilted one. Digestibilities of dry matter, crude protein, NEF and crude fibre in a high moisture silage and those of crude protein, NEF and crude fibre in a wilted one were all significantly higher for the (H) than the (L). DCP and TDN contents were significantly higher for the (H) than the (L) both in high moisture and wilted silages. Significantly more nitrogen was retained for the (H) than the (L) both in high moisture and wilted silages. The differences in the digestibility and efficiency of nitrogen utilization between the (H) and (L) silages are seemed to be mainly due to the difference in chemical quality between these silages.
