Results of experiment analyzing the factors affecting silage effluent production

One of the outputs of Sustainable Silage project is the document presenting the results of the experiment, which was conducted in Finnish Natural Resources Institute (LUKE) in 2023-2024. This experiment contributed to the project with valuable insights about optimizing silage management practices at farm level.

The aim of the experiment was to analyze the effects of different management factors on silage effluent production and nutritional losses. In the experiment 3 types of raw materials were used: intact grass, biorefined pulp and wilted grass along with 3 additive treatments: control, formic acid and lactic acid bacteria. Following a 3-months ensiling period, samples were taken and the chemical composition, fermentation quality, microbial quality and aerobic stability was analyzed. Effluents were collected exclusively from the intact grass silage, as it was the only silage type producing effluents.

Key findings from the study include:

• Silage effluent had a lower pH, and due to reduced degradation, formic acid-treated silages had lower crude protein concentrations.

• Both biorefining and wilting processes led to a reduction in water soluble carbohydrates (WSC) of the grass.

• All silages were well-fermented, with formic acid-treated silages exhibiting superior quality.

• Restricted fermentation in the formic acid-treated silages resulted in lower lactic acid concentrations, leading to higher residual WSC, particularly in wilted grass.

• The intact grass silage, characterized by low dry matter content, produced the most effluent. Effluent production was highest when formic acid was used as an additive.

The findings of the results were presented in Nordic Feed Science Conference in Uppsala in 18.-19.06.2024 and are published in scientific articles:

1) Ayanfe, N., Franco, M., Jalava, T., Stefański, T., Rinne, M. 2025. Chemical characterization and biorefinery efficiency of timothy grass and pulp silages. Grass and Forage Science 80:e12722. https://doi.org/10.1111/gfs.12722

2) N. Ayanfe, T. Stefanski, T. Jalava & M. Rinne. 2024. Grass for biorefinery: effect of additive treatment on fermentation quality of ensiled intact grass and pulp. Editors: Udén, P., Eriksson, T., Kronqvist, C., Spörndly, R., Rinne, M., Prestlokken, E., Gonda, H., Huhtanen, P., Weisbjerg, M.R. & Rustas, B-O. Proceedings of the Nordic Feed Science Conference, Uppsala, Sweden 18-19 June 2024. Reports from department of applied animal science and welfare, no. 3/2024, Swedish University of Agricultural Sciences. pp. 110-112. DOI: https://doi.org/10.54612/a.4h6nuvh43i

3) M. Franco, N. Ayanfe, A. Okkonen, A. Ellä & M. Rinne. 2024. Field survey on the silage quality of Finnish farms. Editors: Udén, P., Eriksson, T., Kronqvist, C., Spörndly, R., Rinne, M., Prestlokken, E., Gonda, H., Huhtanen, P., Weisbjerg, M.R. & Rustas, B-O. Proceedings of the Nordic Feed Science Conference, Uppsala, Sweden 18-19 June 2024.Reports from department of applied animal science and welfare, no. 3/2024, Swedish University of Agricultural Sciences. pp. 104-106. DOI: https://doi.org/10.54612/a.4h6nuvh43i

The main findings are presented in presentation, which is available in Sustainable Silage project webspace here: https://centralbaltic.eu/project/sustainable-silage/103-project-materials/

More information: Marketta Rinne, Research professor of Luke, marketta.rinne@luke.fi