Better barley: There’s a long wish list for brewers and feeders

Yield is No. 1 for growers but elements such as ‘Lox,’ beta-glucan, and acid detergent fibre are key, too

Ask most barley producers what they want in a variety and the answers won’t surprise you: Better yield, standability and disease resistance.

But when it comes to buyers, it gets a little more complex. Both foreign and domestic customers — especially beer makers, but also feeders — are looking for traits few people even thought about until fairly recently.

But they’re priorities for Aaron Beattie, an assistant professor at the University of Saskatchewan who has been breeding barley varieties at the university’s Crop Development Centre since 2006. Here are key traits that he, and other barley breeders, are focusing on.

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Better harvests

Yield tops producers’ wish list but first you must deal with factors that prevent a crop from reaching its highest potential.

One is lodging, which Beattie considers one of the biggest and longest-running agronomic challenges.

“We focus a lot on lodging resistance in barley,” he said. “If you are straight cutting, having a crop that stands better makes harvest so much easier and quicker since you can leave it standing longer. And if you are swathing, the process goes a lot smoother with a standing crop.”

Beattie has cultivars in the pipeline that offer superior standability, but there are also some varieties already on the market which are significantly better than older ones.

“I would say that the newer varieties that have come out of our program — like CDC Bow and CDC Fraser — have already made improvements on lodging compared to old varieties like CDC Copeland and AC Metcalfe.”

Disease resistance is a focus of nearly every breeding program. In the case of barley, better resistance to fusarium head blight (FHB) is arguably the gold standard.

“We focus a lot on better FHB resistance. It seems to be the No. 1 disease that gets talked about in nearly all cereals,” said Beattie.

But what about barley specifically engineered for better yield?

All varieties being produced by the western Canadian programs — malt or feed — feature better yield than any currently on the market, he said. The yield gap between feed and malt barley is closing, with in-pipeline malt varieties within a couple of percentage points of feed varieties.

Better traits

Canadian malt barley has a sterling international reputation.

“Most markets buying Canadian barley tend to blend it with malting barley from other parts of the world to bring up the quality of the overall product they are using to make beer,” said Beattie.

But staying on top means moving ahead and continually delving deeper into the biology of the cereal.

One example is Lox.

Not to be confused with the smoked salmon you put on bagels with cream cheese, lipoxygenase is an enzyme found in barley seed. It’s responsible for a degradation process that creates undesirable traits such as stale flavour and foam instability. Japan’s Sapporo, for example, uses ‘no Lox’ varieties for some of its beers.

The Crop Development Centre has a special program dedicated to incorporating the no-Lox trait into malting barley, said Beattie. Some are already on the market.

“Loxless varieties like CDC PlatinumStar or CDC Goldstar have a natural variant of the Lox enzyme which is defective — that is, it does not work,” he said. “As a result, there are few of the compounds which create that stale flavour or foam instability.”

The search for lower glycocydic nitrile (GN) is an example of a problem that researchers in other parts of the world have identified and in turn, is driving research efforts here.

“GN is a compound which is produced in the malting process,” said Beattie. “When that compound enters the distilling process at high levels it produces carcinogenic compounds.

“In Europe, they have developed some barley varieties which lack that particular compound. We and other programs in Western Canada are starting to incorporate that into our breeding lines with the idea that in the future — maybe 10 years — we may have a Canadian-adapted barley variety lacking the ability to produce GN.”

Better brewing

There’s a lot going on in the brewing process, and there are many factors that either interfere with or help the process.

Beta-glucan, for example, is a gummy substance that can slow down the filtering process during brewing. Western Canadian breeders have greatly reduced the amount of beta-glucan in new varieties.

“If we were to compare beta-glucan content in newer malt varieties to AC Metcalfe, for example, I would say the new varieties are 25 to 50 per cent lower,” said Beattie. “All the new varieties have hit that mark. I think we’ve made some significant progress that the maltsters and the brewers are quite happy with.”

Breeding programs also focus on extract, a measurement of the amount of alcohol that can be made per unit of malt.

“We measure extract in terms of half or three-quarters of a per cent gain. The newer varieties might be up to one per cent better in terms of extract yield compared to AC Metcalfe or CDC Copeland. They’re small gains but still significant.”

Free amino nitrogen (FAN) is a measure of amino acids that are a feedstock for yeast in the alcohol production process. However, the need for FAN varies depending on what individual brewers are looking for in their end product.

“If you are using a lot of adjunct like rice or corn to make the beer, you are going to need a lot of FAN to feed that yeast,” said Beattie. “But if you’re making all-malt beer, the yeast isn’t working as hard and as a result the FAN content can go down a little bit.”

Commercialized varieties that have made progress with beta-glucan, extract and FAN include CDC Fraser and AAC Synergy.

“They already have low levels of beta-glucan and higher levels of extract. Their FAN falls into the current range required by brewers.”

But it’s an ongoing effort, he said.

“The new varieties that are starting to take up acreage show improvements on all three of these characteristics but we continue to try to lower the beta-glucan, further increase the extract and we have a little bit more leeway with the FAN value.”

Better digestibility

Feed isn’t as sexy as beer but feeders have their wish list, too.

Two key factors are acid detergent fibre (ADF) and neutral detergent fibre (NDF).

ADF is essentially a measurement of the least digestible part of a plant while NDF measures the amount of time it takes an animal to digest bulky material, said Beattie.

Ideally, the entire plant would provide energy to the animal in an efficient manner, but that’s not always realistic.

“With high ADF you have a lot of hard-to-digest material such as lignin and cellulose,” he said. “The animal is expending a high amount of energy trying to digest the barley. As a producer, that is not really great if you’re trying to bulk the animals up in a certain amount of time.”

High NDF, meanwhile, causes the animal to take a long time to digest bulky material.

“In terms of breeding goals we are trying to lower ADF so it decreases the amount of lignin or cellulose per unit of volume. A big thing in the animal nutrition world is trying to increase the digestibility of NDF so the animals can get through that bulky material a bit quicker and therefore can consume more over the course of a day or a week.

“Simply put, we are trying to lower ADF and increase the digestibility of that NDF portion.”

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