Low-lignin alfalfa – What have we learned so far? – Kate McAndrews, Vita Plus

By Kate McAndrews, Vita Plus regional sales manager
With many acres of alfalfa planted and harvested for dairy cattle, low-lignin alfalfa has been a quick-to-adopt forage variety by several dairy farmers here in central Minnesota.  As with any new technology, more experience and analyses will allow us to gain more insight into low-lignin alfalfa’s benefits, but our initial observations are very positive without major drawbacks at this time.

Dr. M. Scott Wells, forage and cropping specialist at the University of Minnesota, has trialed low-lignin alfalfa, which supports the information other universities and companies that promote the technology have shared.  His research showed that low-lignin alfalfa has similar tonnage, but better quality compared to conventional alfalfa varieties.  Our team of nutritionists in Minnesota has seen similar results, perhaps with a slight advantage toward increased tonnage.  In reference to better quality, this means higher digestibility and, thus, higher relative forage quality (RFQ), as reported on forage lab analyses.  With the increased attention to uNDF240 – the undigested neutral detergent fiber remaining after 240 hours – and rate of digestion on sample analyses, these calculations should continue to be evaluated alongside digestibility for the forage, but also how the lactating cow ration is comprised of other forages and feedstuffs.

Wells also pointed out the increased flexibility with harvest timing.  For example, producers can harvest closer to 32 to 34 days between cuttings, as opposed to 28 days, which reduces wheel traffic frequency on the fields.  This has a positive impact on subsequent cuttings due to better quality stands, which also yields more tonnage.  Having an adequate stand prior to winter is thought to secure better ground cover to capture more snow to protect the alfalfa roots by insulating them, but other factors also contribute to alfalfa stand damage by the time spring arrives.

Farmers have also started thinking about the changes low-lignin alfalfa could play in their cropping schedule.  By extending four cuttings per season by four to six days each, the timing after fourth cutting could restrict the option (or urge) to take a fifth cutting due to the calendar, but your total yield throughout the season could result in the same tons as if a fifth cutting had been taken.

The productivity of the low-lignin alfalfa plant will also be interesting to follow in the coming years.  Conventional alfalfa varieties are very productive for three to four years, and the low-lignin varieties are more productive for four or five years.  With these benefits, the technology will likely continue to gain interest.  As farmers are true environmentalists, crop rotations are very important for nutrient inputs, so that will be the next area for them to ponder.

Lastly, on the topic of cost and profitability, Wells stated they removed the economics from the comparisons in his research because each farm’s forage program is different in terms of crop rotations, forage inventories, feeding amounts, forage quality goals, and how those decisions impact cow performance and herd goals.  Implementing a forage cost analysis, including forage harvesting costs, for a few years would be a good starting point to learn if low-lignin alfalfa could work on your dairy farm.  Alongside that, working on ration strategies and a feed cost analysis to best determine productivity from your dairy cows while utilizing low-lignin alfalfa will allow you to gain input from a cow perspective to help your decision-making process.

If you are interested in learning more about low-lignin alfalfa, work with your forage and nutrition consultants.