Skip to main content
Research article - Peer-reviewed, 2010

Effect of wilting, silage additive, PEG treatment and tannin content on the distribution of N between different fractions after ensiling of three different sainfoin (Onobrychis viciifolia) varieties

Lorenz Martin, Eriksson Torsten, Udén Peter

Abstract

Sainfoin (Onobrychis viciifolia) is a tanniniferous, leguminous plant that has potentially beneficial effects on protein utilization in ruminants. As ensiling causes protein breakdown and elevated levels of buffer soluble N (BSN), we studied the distribution of N before and after ensiling sainfoin. Three varieties of sainfoin were either direct-cut and frozen directly or wilted and frozen before later ensiling in mini-silos with and without acidification with Promyr (PM; an acidifying commercial mixture of propionic and formic acid) and with or without polyethylene glycol (PEG). Extractable tannins (ET) and protein-bound tannins (PBT) were measured with an HCl/butanol method in an attempt to correlate tannin levels to N fractions. The sainfoin silages showed good ensiling characteristics and had relatively high concentrations of undegraded protein. The effect of wilting on BSN levels (g/kg N) was dependent on sainfoin variety (P < 0 center dot 001). PEG increased and PM decreased the level of BSN in the silages (P < 0 center dot 001). PM treatment also produced less non-protein N and ammonia-N (P < 0 center dot 05) as compared with no additive. Addition of PEG to the silage increased the BSN-proportion 1 center dot 8- and 2 center dot 6-fold for both DM stages. A strong tannin-protein binding effect is, therefore, confirmed in sainfoin. However, correlations between tannin levels (ET and PBT) and BSN were poor in the (non-PEG) silages, indicating either that the HCl/butanol method is unsuitable for measuring tannin in silages or that qualitative attributes of tannins are more relevant than quantitative. The HCl/butanol method seems therefore not to be useful to predict degradation of protein in sainfoin silages.

Keywords

sainfoin; legumes; tannin; silage; protein; nitrogen

Published in

Grass and Forage Science
2010, volume: 65, number: 2, pages: 175-184
Publisher: Blackwell Publishing Ltd

Authors' information

Lorenz, Martin
Swedish University of Agricultural Sciences, Department of Animal Nutrition and Management
Swedish University of Agricultural Sciences, Department of Animal Nutrition and Management
Swedish University of Agricultural Sciences, Department of Animal Nutrition and Management

UKÄ Subject classification

Agricultural Science
Veterinary Science
Animal and Dairy Science

Publication Identifiers

DOI: https://doi.org/10.1111/j.1365-2494.2010.00736.x

URI (permanent link to this page)

https://res.slu.se/id/publ/30201