HAY THERE

By Melyni Worth PhD. PAS. June 2002

During winter most horse people are regularly dispensing their winter feed supply - most often their hay. So maybe a few words on the subject of hay would be timely.

Hay is preserved grass that has been dried to less than 20% moisture content.  Hay is (or should be) the primary wintertime feed stuff of horses. Hay making is a fine art and a science. It takes a good, observant haymaker to have made a decent crop in the wet and cool summers we sometimes get and well as in the rainy hot one we just had. An important thing to understand about hay is that hay making can only preserve the quality of what is present in the field at the time of haymaking. If the grass is poor quality, full of weeds and too mature, then making it into hay will not improve the feed quality and will in most cases decrease it. It takes good quality grass cut at the right time to make good hay.

As the grass plant grows during the spring, it will lay down cellulose and then indigestible lignin in the leaves and stems as they develop; finally the plant will produce flowers and then seeds ready for next growing season. At this stage the plant is done with its life cycle and will die leaving the lignin filled skeleton of stalks and leaves. In order to make good hay the farmer must catch the grass at just the right moment it its lifecycle, when it has produced the maximum leaves and stalks and before it has produced the seeds, or as is commonly said "gone to seed." Hay made from grass which has gone to seed will contain plenty of stalks and lignified leaves but will have very low feed value. Hay made too early in the plant's life will have a high moisture content and will tend to crumble easily when dried, but will have a high level of digestible nutrients . However, grass cut too early will be hard to dry and suffer lots of leaf drop and! hence nutrient loss. Thus good hay making is a balance between too much lignin (grass too old), and too little (grass too young).

In a field containing mixed grasses not all the plants will be flowering at the same time. Generally in a mixed sward some grasses will be flowering, some will be gone to seed and some will still be in the pre-flowering state. Making hay from mixed grasses is a hit or miss exercise, and one can never be sure when the mixture is at optimum nutritional status. The task is much easier when all the plants are of the same species such as timothy or orchard grass. Since all the plants were planted at the same time and all have a similar lifecycle, the chance that all plants are at the same stage of development is much greater. The better quality hays are usually made from specifically grown plants, rather than a mixed stand of unknown composition.

Hay is usually named after the parent grass or legume or after the name of plant which is present in the highest percentage. Thus Timothy hay is made from timothy grass. Lespedeza hay is made from the legume, lespedza. Fescue hay is made from fescue and so on and so forth. Mixed grass hay is a mixture (which might or might not be known). The feed quality of the final product depends not only on the quality of the original plant, and the stage of development the plant was at when cut but also on how well the hay was dried out and stored after cutting.

Drying is the most important part of hay making. If the hay does not dry quickly enough then mold can become established on it and the hay will be toxic to horses. To help speed the drying process many farmers use a process called mower-conditioning. Mower-conditioners will crush the plant stems as they cut, thus allowing the plant to dry faster. This is more important when making hay from legumes such as alfalfa since they tend to have thicker stalks which take longer to dry. Unfortunately, in speeding up the drying process the mower-conditioner also allows the hay to deteriorate faster. While it is often better made, it will deteriorate faster when stored in the barn due to the exposure of the stalks to air, bacteria and molds.

If the hay gets rained on after cutting it will of course take longer to dry out and may become infected with mold. The younger the plants are at cutting and the higher the nutritive value of the plants the faster the molds will move in. If the grass is cut after flowering when there is little or no nutritive value then the drying out is not so critical since the molds will move in slower due to lower feed value. Of course the horses don't do so well on such hay either, but at least they won't develop an allergy to the mold spores and get COPD or "hay -cough".

Hay for horses should be stored under cover and should always be "put up" dry. Horses are VERY SENSITIVE to mold toxins in feed and careless storage or putting the hay up too damp will result in mold growth and health problems in the horses who eat it.
Horses tend to prefer stalky plants in their hay and thus prefer hay made from grasses such as orchard grass and timothy over the softer, leafier meadow grasses such as brome, red top or fescue. Most horses love the taste of alfalfa but alfalfa tends to have too high a protein content for most adult non-working horses. It's a good hay for broodmares and young stock but should be fed with caution and in limited amounts to adult non-breeding horses. A flake a day as a treat is enough for most, but give plenty of stalky grass hay as the main ingredient of the ration.

When buying horse hay, above all make sure it is CLEAN (as in LOW MOLD). There is no such thing as mold-free hay but mold content of hay should be minimized in horses. Over time, continual exposure to the molds will cause allergies in horses, who can lose up to 3/4 of their functioning lung surface. Hay which produces a white cloud when shaken, or puffs of white when opened, SHOULD NOT BE FED. Even if no mold is visible, puffs of white or a moldy smell are clear indications that mold is present, SO DON'T FEED IT. Give to a cattle farmer or landscaper as mulch, and don't even store it near the horses.

Cleanliness of hay is more important to horses than actual feed value. Most horses get plenty of nutrition from the excessive amounts of grain and concentrates they are fed. So if your choice is between high feed value hay with mold in it, and low feed value with little mold then pick the latter. The best, of course, is high quality hay with little or no mold. Feeding good hay can make quite a difference to your feed bills and to your horse's appearance by the end of the winter. If you are feeding pregnant mares, avoid fescue hay, they will have problems with endophyte toxicity. Also avoid unpalatable hay. Hay which lies on the ground uneaten, will do nothing for an animal's nutritive needs.

Horses should get plenty of hay in the winter. Hay helps them stay warm and helps to prevent colic and other digestive upsets. As a rough guide line, a 1200lb horse should eat 1/2 to 1 bale (20-40lbs) of hay a day minimum. So when you buy your hay you need to calculate 1/2 bale per horse per day for 5-6 months (minimum). (Roughly 75-100 bales per horse minimum.) This is a maintenance ration. Any extra nutritive needs can be met in the grain portion of the ration. In any case, get the best hay you can afford. Wasted hay and vet bills for sick horses will soon eat away at any savings you might make on the cost of hay by buying cheap or poor quality hay. If horses consistently reject hay, it means that the hay is not of good enough quality. Most horses will greedily eat good hay and very few will reject it unless there is a problem. If a horse won't eat the hay, don't just leave it in the stall, "until he learns to clean it up." It won't happen! ! The horse will continue to reject the hay and will get sick or lose weight instead. If a horse rejects the hay, take it out and replace it with fresh and hopefully better hay.

Learn to identify good hay. It should:

1) Be free (as much as possible) of mold. So no moldy smell. Open a bale to check. And clouds of mold puffing up when hay is shaken. Reject any bales you suspect of containing mold.

2) Be crisp and clear in color. The exact color depends on the grass/legume cut. The outside of the bales which have been exposed to air might be brownish but the inside stuff should be greeny gold. Good hay is rarely black, dark brown or medium brown in color. The only exceptions here are some clover and lespedeza hays which tend to go brown in storage but are fine in nutritive quality. BUT with all legume hays, be especially careful of mold. Molds LOVE legumes!

3) Be palatable. This means the horses eat it willingly and clean up all they are given! The ONLY place hay can benefit the horse is in its stomach and if it won't eat it, it means that something is wrong!

4) Have minimal weed content. Particularly minimal thistle content. Horses won't eat hay with a lot of thistle and other weeds. See above comment!

5) Have individual grass stalks or legume plants that are clearly distinguishable, not all smushed together into an impenetrable mass. The latter is a sign of hay that was baled too wet and usually has with a high mold content.

There, stay warm in the winter chill and may all your trail rides be good ones!
 

For further information, contact DR Melyni Worth at melyni@intelos.net or call 540-942-4500.

Dr. Melyni Worth Ph.D. - 2004 (c)

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