O116 Autumn grass ensiled with hydrolysable tannins vs a lactic acid bacteria inoculant: effects on the performance, excretions of dairy cows

Silage additives are commonly used to improve the quality of autumn grass, that generally has a low DM content, lacks sugars and contains a lot of (degradable) protein. Hydrolysable tannins (HT) show potential as silage additive as they could reduce proteolysis and thus improve protein quality (De Boever et al., 2020). Additionally, tannins have the property to form pH reversible tannin-protein complexes that are undegradable in the rumen. Therefore, they can shift N excretions from urine to faeces, decrease milk urea concentration, improve milk nitrogen efficiency (MNE) and reduce methane emissions. Thus tannins might be an interesting mitigation strategy to lower the environmental impact of ruminants (Colombini et al., 2009; Herremans et al., 2019).