Nutrition
Sainfoin provides a superb forage for grazing animals and voluntary intake of sainfoin by cattle and sheep is 20% higher than for grass. Unlike many other legumes, it is non-bloating and is known to have anthelmintic properties, so reducing the problems associated with livestock worms. Sainfoin contains condensed tannins, and it is these that protect animals against bloat. Sainfoin has also been shown to increase protein absorption. This, combined with its other health benefits, mean that animals grazing sainfoin have very rapid liveweight gains, so young stock can be finished sooner and with very good carcass grades. Sainfoin is therefore extremely useful to low input and organic farmers. Yields can be very high at around 16t DM per hectare.
Methods and research techniques have been studied and developed to look specifically at Sainfoin polyphenols which include tannins and flavonoids. There are significant differences between Sainfoin types and this will lead to further development of Sainfoin plant breeding.
One method for improving nitrogen utilisation by ruminants and reduce greenhouse gases (CH4, N2O), without altering their nitrogen and energy value, is to use forages that contain condensed tannins, such as sainfoin. The nutritive value of sainfoin, despite its lower nitrogen content than lucerne, is high. Future research, on the nutritional impact of condensed tannins is likely not only be based on condensed tannin content, but also include structure-activity considerations. The results obtained, with sheep at maintenance fed a diet containing only sainfoin will be tested with producing animals, for example growing sheep and cattle, lactating ewes, goats or cows. In producing animals the diet will comprise different forage sources and supplement feeds.
Sainfoin is seldom used as a pure crop and is generally introduced in pasture in a grass-legume mix with cocksfoot (Dactylis), ryegrass (Lolium) or with other legumes such as red clover, white clover or lucerne. Results have shown the choice of the variety is important. A variety like Esparcette, characterised by the highest condensed tannin content, may provide beneficial effects with a lower proportion in a mixture with other legumes. Preserving legumes, as silage, is a good way to provide an on-farm source of home-grown energy and protein, offers advantages over traditional haymaking, being less weather-dependent, and allows a high quality of forage during the harvesting period. In particular, wrapped silage bales of sainfoin have great potential in animal nutrition and can be used by farmers, as found that condensed tannin effects were not reduced by this mode of preservation.
