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Sainfoin tannins and their impact on protein degradation during silage and rumen fermentation and testing of novel techniques

Lorenz, Martin (2011). Sainfoin tannins and their impact on protein degradation during silage and rumen fermentation and testing of novel techniques. Diss. (sammanfattning/summary) Uppsala, Sweden : Sveriges lantbruksuniv., Acta Universitatis Agriculturae Sueciae, 1652-6880 ; 2011:72
ISBN 978-91-576-7616-0
[Doctoral thesis]

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The legume species sainfoin (Onobrychis viciifolia) has been shown to contain tannins of particularly beneficial composition for ruminant nutrition. This thesis describes effects of condensed tannins on protein degradation in general and in sainfoin specifically. Five studies are presented that investigate 1) effects of different ensiling treatments on sainfoin, 2) in vitro rumen protein degradation of sainfoin related to tannin content, 3) effects of molecular tannin structure on binding of tannins to proteins 4) modifications of the inoculum in an in vitro protein degradation assay. Results showed that sainfoin had promising ensiling characteristics using different levels of commercial silage acidifiers at dry matter levels ranging from 200 to 600 g/kg (Papers I and II). Buffer soluble nitrogen (BSN) content in silage was as low as 250 g/kg nitrogen when the protein sparing tannin effect was not inhibited by polyethylene glycol. With the addition of polyethylene glycol, BSN levels more than doubled. This protein sparing effect is based on the formation of insoluble tannin-protein complexes that cannot be digested by bacteria. However, these complexes may be unstable at low pH. Paper II showed that natural formation of acids during ensiling and treatment with acidic silage additives, resulting in pH as low as 3.67, did not influence the protein sparing effect of sainfoin tannins. In vitro analysis (Paper IV) revealed that protein degradation was not correlated to tannin content according to the HCl/butanol or radial diffusion assays. Structural tannin characteristics such as degree of polymerization, ratio of cis to trans binding or ratio of procyanidins to prodelphinidins could not explain differences in protein precipitation (Paper V). Further, a promising in vitro protein degradation assay was successfully improved by defaunation of rumen fluid (Paper III). In conclusion, sainfoin tannins showed potential to increase protein utilization by ruminants. It was however also shown that assays employed to measure tannin content were not able to predict nutritional responses probably caused by not yet analyzed factors such as tannin linkage patterns. Future research has to address molecular structure-dependant binding of tannins to proteins before further nutritional research on tannin specific effects on proteins are performed.

Authors/Creators:Lorenz, Martin
Title:Sainfoin tannins and their impact on protein degradation during silage and rumen fermentation and testing of novel techniques
Series Name/Journal:Acta Universitatis Agriculturae Sueciae
Year of publishing :2011
Number of Pages:60
ILorenz, M. M., Eriksson, T., Udén, P., (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. Grass and Forage Science 65, 175-184.
IILorenz, M. M., Udén, P. (2011). Influence of formic acid and dry matter on protein degradation in the tanniniferous legume sainfoin. Animal Feed Science and Technology 164, 217-224.
IIILorenz, M. M., Karlsson, L., Hetta, M., Udén, P. (2011). Recycling of microbial N and the estimation of protein degradation by in vitro gas production. (Short communication, In press, Animal Feed Science and Technology, DOI. 10.1016/j.anifeedsci.2011.07.012).
IVLorenz, M. M., Udén, P. A correlation study between in vitro protein degradation and a wide range of tannin and protein contents of different sainfoin (Onobrychis viciifolia) varieties. (Under review, Animal Feed Science and Technology).
VLorenz, M.M., Alkhafadji, L., Nilsson, S., Udén P. Condensed tannin size and structure dependant binding to proteins in vitro. (Short communication, Manuscript).
Place of Publication:Uppsala, Sweden
Publisher:Swedish University of Agricultural Sciences
ISBN for printed version:978-91-576-7616-0
Publication Type:Doctoral thesis
Article category:Scientific peer reviewed
Full Text Status:Public
Subjects:(A) Swedish standard research categories 2011 > 4 Agricultural Sciences > 402 Animal and Dairy Science > Animal and Dairy Science.
Agrovoc terms:ruminants, onobrychis vicifolia, fermentation, animal nutrition, proximate composition, sustainability
Keywords:legume, sustainibility, tannin
Permanent URL:
ID Code:8285
Department:(VH) > Dept. of Animal Nutrition and Management
External funders:EU FP6
Deposited By: Martin Lorenz
Deposited On:22 Aug 2011 13:03
Metadata Last Modified:02 Dec 2014 10:46
Project info:
Name:The re-invention of sainfoin

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