Sainfoin

Condensed tannins bind soluble protein and collapse the stable protein foam that causes pasture bloat, which is why sainfoin can be grazed pure without the intake management a clover sward requires. The same binding carries protein past the rumen undegraded, so more reaches the small intestine as bypass protein.

Management combines resistant varieties, rotation, monitoring, and — where justified — locally authorized control products applied according to their labels.

Sainfoin is generally regarded as the most useful of the tannin-containing forage legumes because it combines a high capacity to bind protein with comparatively little inhibition of cellulose digestion by rumen bacteria. Tannins that bind protein well but also suppress fibre digestion trade one benefit for another; sainfoin largely does not.

Tannin-containing forages including sainfoin reduce faecal egg output of gastrointestinal nematodes in grazing ruminants, and controlled feeding studies have measured substantial reductions against Haemonchus contortus. This is a supporting measure within a parasite programme rather than a treatment, and it does not replace veterinary control.

Sainfoin evolved on chalk and limestone and performs on shallow, alkaline, free-draining ground where alfalfa is marginal and clover fails. It is intolerant of acid soils and of waterlogging, and a wet winter on heavy land is the most common cause of a lost stand.

Soil suitability should be assessed with local soil survey information and, where available, field testing.

Seed is large and is often sown still in the pod, which changes the seed rate calculation and the drill setting. Seedlings are slow and poorly competitive, so a weedy or cloddy seedbed loses the stand before it establishes, and sainfoin is normally sown into clean ground rather than undersown.

Sainfoin regrows from crown buds and is intolerant of frequent close cutting; two cuts a year suit it where three would suit alfalfa. Stands are shorter-lived than alfalfa and thin progressively, which is the main reason it is grown in rotation rather than as long-term ley.

The flowers are showy and strongly attractive to bees, and seed set depends on insect visits. That makes sainfoin a deliberate choice in pollinator-supporting systems as well as a forage, and it makes seed production dependent on pollinator populations in the same way as red clover.

Sainfoin dries readily and makes hay well, and the tannins reduce protein breakdown during ensiling, which is the opposite of the difficulty red clover presents. Leaf shatter in over-dry hay is the main conservation loss, so it is turned less and baled at higher moisture than a grass hay.

As a legume it fixes its own nitrogen and leaves a residue for the following crop, and because it is grown on the poorer calcareous soils that residue is often the main reason for including it. Applied nitrogen suppresses fixation and is not used on an established stand.

Fertilizer rates, timing, and forms should follow local soil tests and regional guidance. AgricultureID does not publish universal fertilizer recommendations.