Digesting Hay in Different Forms - Equine

Many horse owners have their hay-buying ritual down to a science. But from time to time, owners might find themselves rethinking their ritual, possibly due to drought, floods, or other factors that limit the forage supply in their area.
Fortunately, bales aren't the only hay option. Owners might need to "think outside the bale" and pursue a different form of forage for their charges. Here’s some information about different hay forms owners can consider:
Square Bales
The most common hay form is the small square bale, which can weigh approximately 45 to 100 pounds each, depending on how they're baled. Square bales are fairly easy to transport, feed, and store, and they allow owners to manage each horse's daily intake.
Round Bales
Large round bales are another option, although their weight—typically ranging from 500-800 pounds—generally makes them more difficult to handle. Round bales also foster an increased risk of botulism, and mold can form if bales aren't produced properly. Moisture at the time of baling is key for larger bales types and should not exceed 20%; higher moisture levels increase the likelihood of mold development. One study by University of Minnesota researchers found that hay waste from round bales can exceed 50% when fed without the use of a feeder; the team showed that with a feeder wastage can be reduced to as little as 5%.
Large Square Bales
Large square bales can weigh up to 2,200 pounds and require farm machinery to transport. These bales also require substantial storage room. Similar to round bales, large square bales have an increased risk of molding if not cured properly. However, owners can feed them in flakes for easier daily intake management.
Double Compressed Bales
Square bales can be further compressed for ease of storage and transportation. Double compression usually shrinks a normal, large square bale to the size of a desktop, with a hefty weight of around 25 pounds per cubic foot. Because of the tight compression, there is less likelihood of mold or bug infestation when properly cured and stored. However, once the bale is cut open, it will enlarge to its original size. Like any square bale, the double compressed bales are processed in flake form for easy feeding.
Cubes and Pellets
Hay cubes are formed by compressing hay into small squares or wafers. Hay pellets are produced by compacting and forcing the forage through an opening before cutting the resultant pellet to the desired length and width. Hay cubes and pellets can be advantageous for several reasons, including less waste produced, less storage space needed, increased ease of transportation, and minimal dust produced. However, researchers have found that horses tend to eat hay cubes and pellets at a quicker rate than baled hay, which could increase their risk for choking or developing undesirable behaviors such as wood chewing. Hay cubes and pellets also tend to be more expensive on a per pound basis when compared to baled hay.
Chopped Hay
Hay can be chopped to a length of about one inch for easier feeding and digestibility. Study results have shown there is no difference in daily intake between long-stemmed hay and chopped hay forms. Chopped hay can benefit older horses or horses with poor teeth because it is easier to chew. However, chopped hay can become dusty, so consider soaking it before feeding to help reduce dust concentrations that can exacerbate respiratory issues.
Silage
This conserved forage is produced by anaerobic (not requiring oxygen) fermentation of the nonstructural carbohydrate fractions, making it more acidic and preventing the growth of microorganisms. Historically, horse owners have not typically fed silage to horses, as it could contain Clostridium botulinum, botulism's causative agent. However, when properly produced, stored, and preserved, research results have shown that silage tends to contain low levels of allergens such as pollen or spores.
Take-Home Message
Choosing the right form of hay for your horses requires considering the type of horses you are managing and matching the form to their needs. In addition, consider cost per pound in the decision-making process.

courtesy - Horse Magazine