Question
My hay supplier recently told me all about a new variety of alfalfa (lucerne) he planted and harvested earlier this year; supposedly, it is lower in lignin. He broke open a few bales for me to see what it looked like, and it reminded me of any other well-made alfalfa hay—leafy and soft. Two questions: what is lignin, and is this hay safe for my geldings?
Answer
The succinct answer is yes, reduced-lignin alfalfa should be fine for your horses, so long as your geldings require the elevated nutrition good-quality alfalfa provides.
The word “lignin” comes from the Latin “lignum,” which translates as “wood.” As one of the structural components within a plant, lignin adds rigidity to stems and is also essential for water and waste transport. In short, lignin keeps alfalfa plants—really, all dryland plants, including trees—standing upright, so more leaves are exposed to the sun; more photosynthesis occurs, which encourages growth; and plants can be harvested easily.
According to studies, the reduced-lignin, non-GMO alfalfa variety has 7-10% less lignin than conventional varieties, and the GMO variety has 10-15% less lignin. Horses are unable to process lignin into a usable energy source, so its reduction in alfalfa varieties would not adversely affect the digestibility of the plant by horses and ponies.
Reduced-lignin alfalfa was introduced to farmers in the spring of 2015. For them, the primary advantage is delayed harvesting, sometimes by 10 days, resulting in a 15 to 20% higher yield per cutting, without a compromise in quality. This could lead to an actual reduction in the number of cuttings without a concomitant loss in yield. Farmers realize savings on several fronts: labor costs, equipment wear and tear, and reduced field and plant damage due to wheel traffic.
To the best of my knowledge, no studies have examined the use of reduced-lignin alfalfa in horses, though it would be safe to say that there are likely no problems associated with it as long as it was harvested under optimal weather conditions and there are no signs of mold, dust, or excessive foreign matter.
Most importantly, alfalfa should fit neatly into your geldings’ feeding program based on its nutritional composition and their needs. The reduction in lignin coincides with an increase in digestibility and a reduction of indigestible fiber, which means there is less fiber to help to keep the digesta moving through the gastrointestinal tract. A certain amount of indigestible fiber fosters proper digestive function. With that in mind, few horses merit forage of this quality, so from a practical standpoint, feeding reduced-lignin alfalfa to most horses is not worth the extra cost.
