During a drought, hay quality often becomes poor, the availability of it is reduced and the cost goes up. Hay may be brought from other countries or other areas of the United States. During extremely wet conditions, the same facts are true, but with the added issue of mold in improperly cured hay. A recent trip to a nutrition conference in Europe, where data was presented examining the various types of hay substitutes revealed some useful information.
Hay cubes, not small pellets, can be an effective substitute for regular hay. Transporting hay cubes from an area where the weather was excellent is cheaper than transporting the bales themselves, making quality fiber more accessible.
Haylage, a moist bale made in a similar fashion to silage fed to cows, is becoming popular in some northern states, but has not been fed to horses in many states in the USA. These are the plastic wrapped round bales seen by the side of hay fields in many places. However, in Europe, haylage has been fed and studied extensively. If made and stored properly haylage is very safe for horses. When feeding haylage, it has to remembered that it is heavier than hay, so if you weigh your hay, you will need to feed more weight to equal the same amount of feed. The extra weight is water. There does not seem to be any increase in obesity when haylage is fed, even though it is thought to be higher in energy or protein, however each horse has to be monitored as an individual, since the haylage could be made from a higher quality field than you may have chosen in the past for your easy keeper. There is no problem adapting horses to eating the new feed.
Preparation and storage are very important, so buy from people who are accustomed to making a quality product and store it away from areas where the plastic wrap can be damaged. Examine bales when you open them, as botulism is a possibility if air or mold has gotten into the bale. The incidence of botulism seems to be low in Europe, but must be taken into consideration.