Reality Check for Low-Lignin Alfalfa
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.
The Benefits of Baleage
Baling hay comes with many risks. It can take hours, often days, for hay to dry. While waiting, an untimely rain can hamper quality and put the rest of haying season on standby.
Baleage, a wetter version of hay, lets producers harvest with less weather concerns. Dried hay has to be baled at 20% moisture or less in small square bales and even less moisture for large round bales. With baleage, moisture can range from 25% to 70%. The flexibility allows producers to speed up the baling process, which is good for crop yields. Each day an alfalfa field is driven over after cutting, there is 6% yield lost on the next cutting.
When putting up baleage, cut hay into wider swaths to help shutdown respiration. “If we don’t shut down respiration, the plants break down those starches and sugars, giving off carbon dioxide. You could lose 2% to 6% dry matter,” says Dan Undersander, forage specialist, University of Wisconsin.
Bales with moisture below 25% have stems that might break the plastic. When bales are above 70%, they produce butyric acid and other harmful byproducts due to the fermentation rate and could freeze during the winter.
It’s also important to note baleage below 50% moisture relies on oxygen exclusion for preservation. A layer of white mold on the surface of opened bales indicates oxygen came through the plastic—either too few layers of plastic were used or the plastic was too porous.
Bales higher than 50% moisture content use both oxygen exclusion and fermentation to preserve hay quality. The fermentation produces acids that help reduce the rate of spoilage.
Bales should be wrapped within 24 hours using six layers of plastic wrap to reduce oxygen diffusing through.
The cost of wrapping ranges from $3 per bale when using an in-line wrapper because less plastic is needed to $6 per bale when individually wrapping with six wraps. When using a baleage system, the storage loss reductions can pay for plastic and other costs compared with standard dried down hay.