Enticed by Adam Simper at Wynnstay, Kevin, who manages the farm for Marigold de Quincey, drilled 2ha of the new kale variety Bombardier in mid May 2018 and started strip grazing the field in late October.
The 40 spring-calving suckler cows took to the kale immediately. “I gave them a 10-meter strip to start with, then I moved the fence 2m each day,” says Kevin. “They cleaned up the crop well and ate all the stems and leaves; there wasn’t much left at the end of the day and they were waiting for me to move the fence each morning.”
The cows were back-fenced so they could run back on to the grass. They also had access to straw and feed blocks as part of their diet. “It provided valuable extra winter forage. We overwinter the cattle outdoors – they only come in to calve, so producing as much home-grown forage – of good feed quality – is important to us,” adds Kevin,” who runs the mainly Hereford cross cows on his mixed arable, beef and sheep unit at Upton Magna, Shrewsbury.
The kale seed was drilled on a rough piece of ground that had been badly rutted following a wet winter. The land was disced and then power harrowed and Kevin sowed the seed from a spinner off his quad bike.
“The soil is thin on this part of the farm, and we didn’t irrigate the crop,” he says, adding that the only help he gave the crop was 40 units of liquid fertiliser. “We had no rain at all for a few months; it’s amazing how it survived. I think there must have been just enough moisture to get it going and then enough leaf cover to prevent it drying out completely. At one point the whole crop wilted but it was saved by rain a few days later.”
An extended summer and warm autumn held temperatures above the seasonal norm and the kale kept growing. Even when the cows moved onto the crop in late October it was still growing.
“It was trial and error,” he adds. “But the cattle did well on this kale crop and we grazed it until mid January. They then moved onto grass before coming indoors late February, ahead of calving.”
Kevin plans to follow the kale with a grass reseed and, impressed with the robustness of the crop, he’s growing more Bombardier kale on another field ready for winter grazing in 2019.
More mileage from kale
Poor stem quality – that may have been 60% to 70% of the total yield, has often limited the feed value of forage kales but new varieties, that have softer and more digestible stems, have improved the feed value and utilisation of the crop.
“Bombardier is a good example,” says Limagrain’s forage crops manager Martin Titley. “It was a new variety to the UK market in Spring 2018 and has been bred for improved stem and leaf utilisation.”
Trials have shown that this new variety has a digestibility of 72.2% and a dry matter content of 13.5%, with a relative dry matter yield of 18% above the control variety, that’s 1.74 tonnes more from each hectare. It is expected to produce between 70 tonnes to 80 tonnes of fresh yield per hectare and between nine and 11 tonnes per hectare of dry matter.
“In the past, farmers have faced a bit of a dilemma when it comes to kale,” adds Mr Titley. “If the kale crop is grazed well, then crop utilisation is good but the poor feed value in the stem will limit liveweight gain. A less well-grazed crop, where a proportion of the stem is left, will achieve better liveweight gains but poorer crop utilisation.
“Marrow stem kales like Bombardier are highly digestible and have improved dry matter yields and utilisation potential, can overcome this dilemma.”
Kale is best drilled in May or early June at a seed rate of 5kg per hectare. Farmers are encouraged to opt for varieties that are club root tolerant and where the seed can be supplied with a fungicide seed treatment.
“The great benefit of a kale crop is its flexibility,” says Mr Titley. “It can be used any time from September to February, so it is ideal for outwintering production systems and it is a popular choice for dairy young stock, beef cattle and sheep.”