Haylage, Hay and Grass
In general it is safe to feed ad-lib hay or controlled quantities if weight management is necessary.
Haylage can be better for some horses than hay (the fructan level may be lower) if it is made from old, mixed pasture that has not been artificially fertilised. Haylage made from pasture designed for cattle fattening should be avoided. The fructan levels in haylage might be lower, but it is much more readily digestible so the total load can be higher.
Once a bale is open, use it within 5-7 days or before it develops mould
Reject bales that are "blown" and those which smell vinegary or cheesy
Make sure that the haylage wrap has not been punctured. Haylage requires a denser wrap than silage.
Reject the haylage if it contains soil. Soil contamination can introduce undersirable micro organisms in the gut which can lead to digestive upsets.
Discard the whole bale if any dead or decomposing animals are found in the bale.
Hays vary widely in how much sugar and starch they contain, but typically they’re well below 20%. For a horse that’s actually insulin resistant or laminitic, the target is no higher than 10% when he isn’t being worked. hence the recommendation to soak hay for these kinds of horses.
For very good doers, hay or haylage may need to be limited, but most horses do best with 24/7 access to forage. For IR horses, and horses prone to ulcers or digestive issues, denial of forage can be dangerous.
Fresh grass is about 90% water, 10% nutrients, fiber and minerals, while hay is the other way around. It’s predominately dry matter.
Grass is low in fat, and grass has generally no more than 5% fat in early growth stages of grass. That is on a "dry-matter basis," meaning 5% of the solid component of the grass, after all water is removed. If we assume the horse consumes about 15 lbs. per day of dry matter, that means 0.75 lbs. of fat (12 oz.) when eating young growths of grass. This drops to 3 to 4% when grass is mature, and usually no more than 3% in hays.
The type of fat is also important.
Grasses are high in the essential fatty acids omega-6 and omega-3, with at least four times as much omega-3 as omega-6. Omega-3s are fragile, rapidly destroyed by processing.
Low Grade Laminitis and Grazing
Ad-lib grazing, especially on spring and summer grass, can make many horses footy – this may show as a very low grade lameness, changes in stance, unwillingness to go forward, short striding, or in some cases full blown laminitis. Sometimes a precursor to the problems in the feet may be itchiness or uncharacteristic changes in temperament.
If in any doubt, take the horse off the grass completely for at least a week, feed only soaked hay, and see if it improves.
We all know how challenging it can be to arrange grass free accommodation in the average livery yard, but there may be lanes and areas of waste ground that can creatively be brought into use.
It is tempting to reduce vigilance in winter as the grass is not growing as quickly as it does in summer, and many cases of laminitis happen in November through February. Even a couple of sunny days in winter can turn a paddock from “safe” grass to “dangerous” grass.
During “high risk” periods (generally spring or summer, but can be longer in very fertile areas), grass is usually safer at night (due to lower fructan levels) and when it is reasonably long. Short, over grazed, stressed grass is highest in fructans and therefore carries greatest risk, and generally it does not give the horse sufficient fibre which places further stress on the digestive system.