I believe that hay cubes or alfalfa cubes are very useful there where there is no hay available or the quality of the hay is very poor. However, if the hay is available and of good quality I do not like to replace it with the cubes.
Alfalfa in itself is fairly high in protein and feeding it with other high proteins feeds should be avoided. A good addition to the cubes may be a soaked beet pulp mixed with grains if grains fed. If there is a chance that you can get regular hay cubes it is recommended to mix them half and half with the alfalfa cubes.
One slight drawback; one cannot tell the quality of the hay when it is cubed nor the horse can tell the difference should there be accidentally some poisonous plant present. Another important fact is to pay a great attention to hydration of the horse; make sure that he has plenty of fresh water.
The water should be clean and fresh (no electrolytes). When feeding mainly hay or cubes it is recommended to feed a bran mash once or twice per week.
Nutritional value: crude protein 17% minimum, crude fiber 28%, moisture 10 maximum, digestible energy 2.68 mcal/kg, rich in carotene 57.8 mg/kg, calcium 1.5 %.* * * Below is a publication by Dr. R.J. Coleman, which describes in more details about feeding alfalfa cubes.
Alfalfa Cubes: An Alternative Forage
Good quality forage is the basis of feeding programs for all horses. When hay is being fed, horse owners need to select a hay that is nutritious but also free of dust and mold. However when mold-free hay is not available, horse owners can consider the use of alfalfa cubes as a viable forage alternative.
The difference between alfalfa hay and the alfalfa cube is the size of the package. With the alfalfa cube, the forage is coarsely chopped and then mechanically compressed into a 1.25 by 2-inch cube. Therefore when horse owners use alfalfa cubes in a diet for horses, the cubes replace hay of a similar quality on an equal basis.
The process of cubing the alfalfa does not affect the availability of nutrients to the horse. Research reports indicate that the availability of the energy and protein is the same in cubed as alfalfa hay.
It is important, however, for horse owners to control the feed intake of their horses when using alfalfa cubes as the forage source. Research conducted in Alberta, Canada noted that the voluntary feed intake of mature horses was 20% greater with alfalfa cubes than with alfalfa hay. Horse owners that do not control the consumption of a high quality hay cube will have overweight horses or an increased incidence of digestive upsets.
Because the forage is chopped prior to cubing, a common concern with horse owners is that their horses will eat faster and possibly develop bad habits such as wood chewing on a cube-based diet. Research at Colorado State University would suggest that other factors such as boredom and weather are responsible for horses developing the habit of wood chewing, not the use of cubed alfalfa as the forage.
Advantages of alfalfa cubes are reduced feed wastage, consistent nutrient quality, ease of handling, and allowing horse owners to regulate feed intake and reduce potential exposure to dust and mold. This later advantage is important for horses with respiratory problems.
Disadvantage are the cubes must be fed in a controlled manner to prevent over consumption and there may be an additional cost due to processing. When all the advantages are considered, alfalfa cubes can provide horse owners with a high quality, nutritious, and convenient product that is a viable alternative to hay in feeding programs for their horses.