On livestock farms in Denmark, a hybrid rye revolution is taking place.
Traditionally rye has been grown for milling, but Jacob Nymand, KWS agronomist and feed specialist in Denmark, says in the past few years the crop has become so popular as a grain source for dairy cattle and pigs that the amount grown in the country has trebled.
“We didn’t even have enough rye to meet human consumption [50,000ha was required], but then the new hybrids were released and farmers got really interested in growing the crop.
Benefits of hybrid rye
- Hybrid rye requires 30% less water than other cereals, so is extremely drought-tolerant
- Being deeper rooted to 1.5m, it is better able to use nitrogen reserves; typical N use in Denmark is 130-150kg/ha in three applications
“Within a year we were up to 60,000ha and now the country is growing 150,000ha,” he says.
About 80% is grown for pig production, with the remaining 20% being grown by some of the country’s 4,000 dairy producers.
But the area sown is expected to increase to 250,000ha by 2050 – largely at the expense of second wheats.
This is mainly as a result of trials in Denmark, which found hybrid rye produced average yields were 17% bigger than wheat’s and triticale’s and 22% ahead of winter barley’s.
By 2018, he predicts the yield gap to grow by 33%.
Kim Kjaer Knudsen, Zealand, Denmark
Pig and arable farmer Kim Kjaer Knudsen has been growing hybrid rye in favour of second-year wheat for the past three years.
He says it is not only more cost-effective to grow, it is higher yielding and is helping them to better control the weight of sows and finishers.
“We were not satisfied with our second-year wheat and wanted to try something different. We first tried triticale and then rye,” Mr Knudsen explains.
- Farms in partnership with his brother and father
- 2,200 sows across two sites, fattens 75,000 piglets a year across seven sites
- Supplies Danish Crown
- Averaging 35 piglets weaned a sow a year
- Piglets are finished at 24 weeks of age weighing 110kg
- Year one: Wheat
- Year two: Hybrid rye
- Year three: Oats
- Year four: Winter barley
- Year five: Rape seed
He was so impressed with the results that he is now growing about 200ha of hybrid rye.
The seed is planted in September and is harvested the following August.
Mr Knudsen uses a reduced tillage system, preferring to harrow before reseeding.
“We can see it is a better strategy. It leaves more organic matter in the soil, withholds more water and nutrients and absorbs more rainwater.
“When you plough you lose a lot of carbon from the soil to the atmosphere, which is a loss for the environment and your pocket.”
Mr Knudsen says another benefit of reduced tillage is that it decreases fuel consumption slightly.
Although the initial cost of hybrid rye seed is double the price of wheat seed, at about £30/ha, Mr Knudsen says the seasonal cost saving – driven by reduced chemical use and higher crop yields – more than compensates for the higher outlay.
At last harvest, the hybrid rye yielded 1.5t/ha more than the second-year wheat – accumulating to an overall yield increase of 200t from the same land.
The hybrid rye is also cheaper to grow in the season because it is less susceptible to diseases such as tan spot (DTR), which means it requires fewer applications of chemicals.
The rye is sprayed once in February, followed by a dressing of sulphur and 180kg/ha of artificial fertiliser and pig slurry in the spring.
Example finisher’s ration
Example finisher’s ration
This is mixed with water at a ration of 1kg dry matter (DM) to 3.3 litres of water to bring the total DM of the ration to 25%
Once harvested, the rye is stored in gas-tight silos at 84% dry matter (DM) and is used on-farm in the pig rations, alongside the other home-grown cereals.
Wheat, oats, rye and barley are coarsely ground and mixed together with soya, minerals and water at a ratio of 1kg DM to 3.3 litres of water to create a 25% DM soup.
This ration is fed to both sows and finishers between 11 and 24 weeks of age.
Finished piglets are fed in line with a feed curve up to a maximum of 12kg a head a day. In the last few weeks of production the curve plateaus.
Meanwhile, sows are fed automatically using electronic tags, to reflect their body condition.
“Each sow is fed according to her back fat. What’s important to us is we have a simple sow coming into the farrowing unit that is fit to produce.
“Before we were visually scoring sows, but sometimes a fat sow can look a bit skinny,” explains Mr Knudsen.
This protocol is much more objective, too. The optimum level of back fat is 16mm; under this, sows are fed more; above 20mm, sows are put on a diet.
Mr Knudsen says feeding sows rye complements this programme because it is lower in energy than wheat.
For the same reason, it works really well in the fattener diets, he says.
“In the latter part of finishing, pigs can grow too fast and produce too much fat and not enough meat. The rye has had a positive effect on fatteners. That means less fat and a higher meat yield of 62%.”
Mr Knudsen says this is key as his contract penalises him if pigs fall below a minimum meat yield of 58.5%. The 3p/kg premium he receives for being UK-certified also gets deducted if meat yields are not good enough.
Hybrid ryes in UK trials
In UK trials over the past two seasons where the best wheats and hybrid ryes are grown alongside each other, rye has consistently outyielded wheat.
According to KWS UK sales manager Bill Lankford, growers who could benefit most from hybrid rye are those on light land and where second wheats are failing to deliver.
“With hybrid varieties yielding 0.5t/ha more than the best feed wheats in our trials, yet costing less to grow, there are significant advantages to be gained.
“As a second cereal in the Yorks Wolds and Dorset, we have seen it outcompete wheat by 1.5t/ha, and in first cereal trials at Cambridge, hybrid rye has done 12.2t/ha.
“While there is no market price for rye at present, assuming it is traded at a 10% discount to wheat and a base feed wheat price of £122/t, rye yielding 5% more than wheat would produce an output that is just £40/ha adrift.”
Farmers growing hybrid rye could also benefit from reduced fertiliser, herbicide and fungicide costs compared with a winter wheat. In fact, even with a higher seed price, the crop is still £70/ha cheaper to grow, says Mr Lankford.
UK trials also show rye outcompetes blackgrass in the autumn largely because of its excellent tillering ability, which smothers weeds. Combined with an allelopathic effect, where its roots produce chemicals that hinder the development of other plants, herbicide savings are likely as well.
KWS’ UK rye crop specialist, Simon Witheford adds: “Agrovista data suggests that only 7% of any remaining blackgrass seed in the hybrid rye crop canopy is viable, whereas that which typically towers over wheat is 28% viable,” he says.