Condensed Tannins in Sainfoin: Composition, Concentration, and Effects on Nutritive and Feeding Value of Sainfoin Forage

Abstract

Legume forage is the most economical source of nutrients for ruminants. Sainfoin (Onobrychis viciifolia Scop.) is high nutritive forage growing worldwide and possesses polyphenolics including condensed tannins (CT) that contribute to some of its superior nutritional properties such as improved protein utilization, bloat‐free, and anthelmintic characteristics. This review attempts to capture the latest research in characterizing the impact of polyphenolics on the feeding value of sainfoin with an emphasis on CT. Sainfoin contains a diverse array of polyphenolics and its CT content declines as the plant matures, with an increase in the degree of polymerization and a decreasing proportion of prodelphinidins, resulting in a reduction in biological activity. This forage is best to be utilized between bud to flowering stage to balance the biological activity of CT and biomass yield. Incorporation of sainfoin into alfalfa (Medicago sativa L.) pasture has been effective in reducing alfalfa pasture bloat due to the presence of CT. New sainfoin populations suitable for survival in high‐performance grazing systems have been developed and have demonstrated superior anti bloat activity due to the increased grazing persistence. Fresh sainfoin is the best feed for cattle for maximum effect of CT, but if it needs to be preserved then hay would be better than silage in terms of preservation of the biological activity of CT. Although greater CT content is desirable for this forage in terms of antibloat and antiparasitic activity, sainfoin with CT concentration at about 50 g kg−1 dry matter (DM) offer the best feed value.

Silages containing bioactive forage legumes: a promising protein‐rich feed source for growing lambs

“…Another factor that may be involved is the content of condensed tannins in T‐SF, as these can act both directly on silage palatability and indirectly via a reduction in OM or NDF digestibility (Frutos et al ., ; Scharenberg et al ., ). However, beyond the fact that the tanniferous SF forage is recognized as highly acceptable to livestock (Khalilvandi‐Behroozyar et al ., ; Wang et al ., ), the CT content in T‐SF was moderate (1·14%) due to its dilution with the T grass, and lower than the range of concentrations associated with a decrease in feed intake (Waghorn et al ., ). Furthermore, the RC‐SF mixture that had a similar CT content was associated with one of the highest intakes.…”

Benefits of Condensed Tannins in Forage Legumes Fed to Ruminants: Importance of Structure, Concentration, and Diet Composition

“…P. North American researchers have also explored oat and alfalfa as companion crops for irrigated birdsfoot trefoil and sainfoin (Wang et al, 2015;Hunt et al, 2016), and this involved developing a new sainfoin population for cocultivation with alfalfa. or undersowing with spring barley (Hordeum L.) as companions (Liu et al, 2008;Mora-Ortiz, 2015;.…”

“…The choice of which forage to grow will depend on the climate, soil, environment, and farming practices. The performance of these forages has been tested in pure stands and in combinations with partner species to increase the overall forage quantity and quality (Häring et al, 2008;de Koning et al, 2010;Döring et al, 2013;Lüscher et al, 2014;Wang et al, 2015).…”

Sainfoin production in western Canada: A review of agronomic potential and environmental benefits

“…In contrast, Häring, Suter, Amrhein, and Lüscher () working in Switzerland found that CT concentrations in leaves doubled with age, but the leaf/stem ratio halved so that the whole plant CT concentration remained the same. Wang () attributed some of the changes in CT concentrations with time and among plant parts to optimization of CTs as defence against grazing.…”