Abstract
For the purpose of investigating the effects of the additive containing sodium nitrite and calcium formate on the quality and keeping property of silage, following three experiments were carried out using each three or four Italian ryegrass samples of different growth stages. In the experiment I, the grass samples were ensiled at three levels of compaction of 600, 450 or 300kg/m^3 with and without the additive and the effect of the additive on the quality of silage ensiled at varying levels of compaction was studied. In the experiment II, the grass samples were preliminarily chopped or unchopped and ensiled with and without the additive and the effect of the additive for improving the quality of unchopped silage was compared with that for the chopped one. In the experiment III, the grass samples were ensiled with 0, 0.1, 0.2, 0. 3 or 0.5% of the additive respectively, and the one of three groups similarly treated was stored for 6 weeks, the second group was stored for 6 months under unfavourable circumstances and the third group was aerated for 15 minutes a day during 2 weeks after 6 week's ordinal preservation, and the effect of the additive on the keeping property of silage was studied by comparing the silage quality of the first group with that of the second group and the preventing effect of the additive on the deterioration of silage after opening the silo was examined by comparing the silage quality of the first group with that of the third group. The results are summarized as follows ; 1. The additive improved the quality of silage ensiled only at a high level of compaction with a very low water soluble carbohydrate (WSC) grass. With a medium WSC grass the quality of silage was improved at every level of compaction and with a high WSC grass it was improved especially at a low level of compaction by addition of the additive. 2. The additive could scarcely improve the quality of uuchopped silage, and it was observed that the chopping was rather effective for improving the quality of silage. 3. Both the keeping property of silage quality and the preventing effect of deterioration of silage after opening the silo were not observed at as much as 0.5% addition of the additive with a very low WSC grass. But these beneficial effects were observed at 0.3〜0.5 % addition of the additive with a medium WSC grass and at 0.1〜0.2% addition of it with a high WSC grass respectively.
