As a tanniferous plant with a tannin content ranging from 4% to 10%, sainfoin has beneficial effects in ruminants. These effects are:
- enhanced sulphur-containing amino acids digestibility (Waghorn, 1990) through tannin protein-binding. This has positive effects on wool production (in sheep) and reproductive performances (Waghorn, 2008) ;
- reduced bloating and dietary methane and ammonia emissions ;
- enhanced animal health through direct or indirect anthelmintic activity of condensed tannins (Hoste et al., 2006).
Because of its crude protein content, sainfoin can improve the self-sufficiency of dairy farms, in terms of homegrown protein-rich forages (Borreani et al., 2003).
Fresh sainfoin is suitable to feed cattle and small ruminants. It is as highly palatable as grasses (Kirilov et al., 2006), or crushed barley and maize silage (Klopfer et al., 1981). Sainfoin grazing resulted in increased body weight gain, wool production and reproductive performance (Waghorn, 2008). It was recommended to grow it as a monoculture in order to have a higher lamb production per hectare (Karnezos et al., 1994). It may also be mixed in grass pasture, where it resulted in greater profitability (Karnezos et al., 1992).
Sainfoin hay is highly palatable, contains more tannins and has a higher metabolizable energy level than Lotus corniculatus and Cichorium intybus (Scharenberg et al., 2007). It has a higher efficiency of N digestion than alfalfa when cut at the vegetative stage (Aufrère et al., 2008). In dairy goats, sainfoin hay was well accepted and a repeated distribution resulted in milk yield, milk fat and protein content similar to grass. Sainfoin hay also decreased nematode infestation (Paolini et al., 2005; Hoste et al., 2006).
Sainfoin silage has a beneficial effect on dry matter intake, dry matter digestibility and cellulose digestibility in sheep (Tatl et al., 2001). Crude protein utilizable in the duodenum and metabolizable energy were also improved (Scharenberg et al., 2007). The silage is also a good source of macro and micro-minerals, except for Cu, Zn and Mg, which should be supplemented. The N digestibility of sainfoin silage is lower than that of other legume silages (Fraser et al., 2000).