Effluent production from grass silages treated with additives and made in large-scale bunker silos

• Published in: Grass and forage science 1999-09, Vol.54 (3), p.208-218
• Main Author: Haigh, P M
• Format: Article
• Language: English
• ISSN: 0142-5242; 1365-2494
• DOI: 10.1046/j.1365-2494.1999.00172.x

Data from twenty experiments, conducted at ADAS Research Centres in England and Wales during 1986–92, were used to determine effluent production from additive‐treated grass silages made in large‐scale bunker silos. The additives compared were formic acid at 4·0  l t–1, rolled barley at 44·0 kg t–1, dried molassed sugar beet feed at 40·0 kg t–1 and liquid inoculants at 2·2 l t–1 together with a non‐additive‐treated control. The silages were made from herbage with an average dry‐matter (DM) content of 177 (s.e. 3·8) g kg–1 and water‐soluble carbohydrate content of 140 g kg–1 DM. Average silage toluene DM content was 213 (s.e. 3·8) g kg–1. The formic acid and sugar beet feed silages were both well fermented, whereas the other silages were less well fermented. Effluent produced was determined as either effluent production (l t–1 grass ensiled) during the 52‐d period in which it was measured or peak flow (l h–1) during the first 2 d of ensilage. Compared with non‐additive‐treated silage, dried molassed sugar beet feed significantly reduced both effluent production (27%) and peak flow (36%). Formic acid significantly increased peak flow (51%), but had little effect upon effluent production, and significantly reduced effluent N and lactic acid content. Barley and inoculant treatment had no significant effect upon effluent production. In general, poor relationships were found between DM content and effluent production. Nevertheless for silages, except those treated with absorbents or formic acid, a significant (P