Two companies will offer low-lignin alfalfa varieties on a bigger scale in 2016, prompting farmers to experiment with the more digestible forage.
Early results of low-lignin alfalfa suggest it will have a wider harvest window, meaning farmers will be able to lengthen the time between cuttings. The result should be greater tonnage per acre over the course of a season without sacrificing forage quality.
“A 15% to 18% lignin reduction means we could harvest eight to 10 days later,” says Dave Combs, a
University of Wisconsin forage specialist. “But the cynic in me, when we look at low-lignin corn, is that there could be yield drag.”
In 2016, Alforex Seeds will offer its Hi-Gest 360 (a fall dormancy of 3) and Hi-Gest 660 (a semi-dormant version with a fall dormancy of 6) low-lignin varieties. The Hi-Gest varieties, with 7% to 10% less lignin than conventional alfalfa, are a result of conventional plant breeding.
Available in limited supplies next year, Forage Genetics International’s HarvXtra variety is a result of genetic engineering. In addition to being low lignin, it will be Roundup Ready.
HarvXtra has 10% to 15% less lignin than conventional varieties.
Combs notes the genetically-modified HarvXtra has the same lignin genes inactivated as brown mid-rib (BMR) corn hybrids. While these BMR corn hybrids continue to improve, they still produce less tonnage per acre than conventional, non-BMR hybrids. As a result, Combs is anxious to see if the varieties will be able to produce the same yields as conventional alfalfa.
Lignin provides structure and strength to the plant, but standability has not been an issue because they were back-crossed with varieties with high standability ratings, he adds.
To date, just two feeding trials have been done with low-lignin alfalfa. One of the trials on lactating cows showed fiber digestibility went up nine units, and milk production increased 2.5 lb. per cow per day.