29 November 1996

Zero-grazed kale lifts milk yields & gives grand saving

Growing and feeding kale has allowed a Gloucester milk producer to cut his feed bill by £1000 a month. Jessica Buss reports

KALE will be zero-grazed until late December on one Cotswold dairy unit after its success last year.

Robert Grey of 270ha (670-acre) Symonds Hall Farm, Wotton-Under-Edge, Glos, found milk yield from his 210 cows – which average 7000 litres a year – rose by one litre a day when zero-grazed kale was introduced to the feed ration last January.

As a result, 10ha (25 acres) of kale was drilled in June to be used as a protein source for this years winter ration.

Since kale, which is over 20% crude protein and has an energy levels of 12-12.7 ME, was introduced in early October, milk proteins and yields have remained the same as when cows were grazing.

Protein purchases for rations have been cut, and the 30t a month of brewers grains fed last year have not been needed. Mr Grey estimates this saves him £1000 a month, and silage requirements are also reduced.

But high phosphorus minerals are needed to compensate for kales low supply. He also warns that it takes cows 10 days to find an appetite for the kale and for their digestion to adjust.

Mr Grey believes kale has good feed potential, but strip grazing has given disappointing results in the past at Symonds Hall Farm. "Cows suffered the stress of walking through muddy gateways and the risk of foot damage. Also, moving fences regularly was hard work."

Cutting kale for zero grazing takes only 20 minutes a day, and Mr Grey feels it is better to bring it to the cows. "Zero grazing kale ensures it keeps all its energy. It also saves clamp space and plastic, which would be needed if the crop was baled for kaleage.

"We had hoped to mix kale in the complete diet but its dry matter is too inconsistent. When it is wet the intake of the whole diet goes down," he says.

Instead, chopped kale is put out using the diet feeder and the complete diet ration spread on top (see table). Cows are also fed concentrates in the parlour.

"Initially cows reach down through the complete diet for the kale, but some stays in the complete diet till the evening, keeping the ration balanced."

Growing costs

Mr Grey estimates growing costs are £129/ha (£52/acre), not including harvesting or labour after drilling. But the arable enterprise on farm means there is plenty of labour available for the winter harvest.

Kale yields 7.5t/ha (3t/acre) of dry matter, but Mr Grey points out that 5t DM/ha (2t DM/acre) of first-cut grass silage was also harvested in late May before sowing kale, giving a total of 12.5t DM/ha (5t DM/acre).

That compares more than favourably with maize, which only yields 8.9t DM/ha (3.6t DM/acre) at Symonds Hall Farm. With land at 243m (810ft) above sea level, maize crops do not yield heavily, he adds. "Kale is an alternative to maize with a similar energy level, but higher protein content."

Although the ground is high, the soils are free-draining and can carry machinery every day. This is essential to maintain a consistent diet, he says.

But kale does not heat up after harvest, so in cold, frosty weather it is possible to cut two days supply at once.

Zero-grazing kale saves Robert Grey £1000 a month on winter feed bills.