Pieces of the puzzle: Considerations for producing quality alfalfa
With increasing livestock numbers, there’s an increased need for quality alfalfa. Just produce more, right? It’s not so cut and dried, according to Emily Glunk Meccage. There are many pieces to the puzzle.
“We have decreased the amount of land actually in production for alfalfa,” Meccage, an assistant professor and forage Extension specialist at Montana State University, said. “So how are we able to meet those needs?”
There’s more than one issue to consider when looking to improve alfalfa production. Cattle sizes have increased through the years and those bigger cattle need more to eat. There’s been a steady increase in carcass weights in the beef segment and increased milk production on the dairy side. Quality forages end up being a must-have for both sides.
“We’re putting up alfalfa because it has high protein, high energy, high digestibility,” Meccage said. “When we do look at alfalfa production in the last couple of decades, it’s similar to those livestock trends. Our production per acre has skyrocketed as well.”
Production is maximized with irrigation and soil fertility. Genetics are also improving quality. But why should alfalfa producers care? Because someone has to buy it and feed it to their livestock.
“A large portion of those animal diets is made up of alfalfa,” Meccage said. “When we look at beef, estimates are about 83 percent, 61 percent dairy, just strictly from forages.”
Many forages are going to be alfalfa, she said. Many states feed large amounts of alfalfa, especially cow-calf operations and dairies. In 2018, there were 16,608,000 acres of alfalfa harvested across the United States, according to the National Agricultural Statistics Service. From that, yields reached 3.17 tons per acre.
Leaves are important
There are a few things to keep front and center when it comes to alfalfa quality, according to Meccage.
“When we’re talking about optimizing a quality, it’s all about optimizing leaf retention,” she said.
Maturity plays a big part in quality, as it depends on what bloom stage the alfalfa is in when it’s ultimately cut.
“The later we wait to cut it, or if we’re getting past 10 percent and 50 percent bloom, we see that leaf to stem ratio go down,” Meccage said. “You see protein go down and fiber increasing.”
The leaves lost force the yield down, and eventually the stem portion causes the yield to increase or decrease. Optimizing quality can be tricky since dairy operations traditionally harvest alfalfa a little earlier than a beef operation to maximize yield.
“Because we don’t need 20 percent protein (for beef), we can get by with 12 to 14 percent protein actually,” Meccage said. “We still can get decent digestibility. We just want to make sure that we have enough hay in our hay yard.”
Dairies have to be mindful of the protein levels that support higher milk production though.
“So it’s a constant trade off to decide when do we harvest,” Meccage said. “Are we looking more to maximize yield? Are we looking more to maximize quality? Are we shooting for the middle?”
But the animals still need fiber—it’s just not going to be as digestible. So keeping the leaves intact is critical.
“So we’re really trying to look for how can we manage for those leaves,” Meccage said.
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What does harvest timing have to do with animal performance? With beef cows, Meccage referenced a study in Nebraska where they used 400- to 600-pound steers and fed alfalfa harvested at varying stages of maturity.
“The earlier we harvested, the higher our gain, but also met the higher the efficiency or pounds of forage to pounds of gain,” she said. “But what are we giving up here, if we’re harvesting at vegetative compared to early bloom?”
There’s a trade-off as to what a beef producer would want. Do they need more pounds of gain with the better quality forage, or could they lose a little bit of quality with the forage and deal with less gain?
“It’s definitely going to be your trade-off,” Meccage said.
With dairy performance, it’s about the same when the forages are harvested earlier.
“We’re going to maximize our milk production,” she said.
As forage quality decreases, milk production is affected pretty significantly.
“This is kind of where we see that quality is going to be more of a factor here versus quantity for that dairy market versus that beef market,” Meccage said.
And for those selling hay on an open market, quality will vastly affect how much money they get for their hay.
“So the earlier we harvest, the higher quality, the higher dollar value you’re going to be getting for that hay,” Meccage said. “But again, you’re going to be getting more tonnage.”
Overall, when looking at the harvesting process, a lot of research has been done looking at losses in terms of both yield and quality.
“There’s been a lot of studies looking at what impact does rain damage have on my overall losses, and it’s significant,” Meccage said.
Rain damage, as small as 0.2 inch, can cause a 5 percent loss, which is “pretty significant,” according to Meccage. The same goes for dry matter loss.
“When we hit 1 inch, research was averaging around 17 percent loss, she said. “When we got 2 inches of precip, it averages around 30 percent loss.”
Leaves tend to take the hit and suffer the larger portion of the loss.
“We know that can be a very critical problem that we have to address,” she said.
Leaf loss comes from the “production process” or the mowing, the raking and the baling. According to Meccage, the raking causes the most significant leaf loss, and alfalfa producers need to be aware of what happens during this time.
“We still have some ways that we can try to decrease that in leaf loss overall,” she said. “On average, with raking, were getting about 5 percent loss. But it ranges anywhere from 1 to 20 percent loss.
So what can be done to keep the leaf loss to a minimum during the harvesting and baling process? Mowing and conditioning overall cause minimal loss.
“We don’t see a whole lot of dry matter loss or quality loss during this initial process,” Meccage said. “But there are some things to consider.”
Studies have looked at the leaf to stem ration prior to cutting, right after cutting and then after baling. In one particular research trial, standing forage leaf to stem ratio was at about 45 to 55 percent.
“Our goal is the best that we can do at that point,” Meccage said. “After mowing, what happened to the leaves didn’t really change. It was about 43 to 57 percent. Not a huge jump.”
But once the hay reaches the raking and baling stage, leaf to stem ratio can get to about 33 to 67 percent. One way to save those leaves is to adjust the mowing/cutter bar.
“What we’re usually shooting for economically, it’s recommended around 2 1/2 to 3 inches stubble height,” Meccage said. “I shoot for about 3-inch stubble height, maybe a little bit higher.”
If the alfalfa is a little more mature with some regrowth already occurring and crown buds already forming, a cutter bar that is too low will cut off vital parts.
“You really do have to be mindful of that maturity as well when you’re making this decision,” Meccage said. “It can be tempting to play the game of how low can I go, because we know that we’re going to gain yield, the lower we put that cutter bar.”
Another thing to consider is the lower part of the plant typically is going to be lower quality.
“If we lower that cutter bar, we’re gaining a little bit of yield, but we’re also losing quality,” she said. “So it’s not necessarily always that win-win situation.”
Three and a half inches would be the minimum height that Meccage would ever recommend in terms of cutting height.
The type, kind and a few other factors also affect alfalfa quality in the bale, Meccage said. One study she quoted looked at speed, bale diameter, windrow density and how it impacted overall losses.
“The more forage you had going into the baler at one time, so triple windrow versus a single windrow, you actually decreased your losses,” Meccage said. “When they went with that single windrow, their average baling losses was about 14 percent, and it decreases down to 5 percent when they have three windrows right together.”
That feat was pretty amazing to her, but the study failed to quantify the extra raking it took to get those three windrows together.
“So it probably does kind of level out anyways,” she said. “You’re going to have more raking losses, less baler losses, but it is something to consider.”
What kind of impact on quality does the baler have on quality and leaf loss?
“Mostly, it’s going to be less than 5 percent,” Meccage said. “Your small squares can actually be a little bit higher (leaf loss) than some of your other pieces of equipment. But again, I haven’t seen really recent data looking at that yet.”
But there have been a lot of improvements in baling equipment in recent years.
“Regardless, your pickup and chamber losses are usually pretty similar,” she said. “So it really depends on kind of where your loss is going to occur. If you can merge three windrows together, that’s great, you’re going to lower your pickup and chamber losses. But again, you’re probably going to increase that raking loss a little bit.”
Kylene Scott can be reached at 620-227-1804 or [email protected].