Switch brings feed rethink
By Marianne Curtis
GOING organic has forced a complete reappraisal of feeding strategy on one Lincs farm.
But new, high clover conservation leys have performed well and should permit a cut in concentrate feeding levels this winter.
Organic conversion at The Grange, Little Bytham, Grantham, Lincs, began in March 1999. The 97ha (240-acre) farm was mixed, selling cereals and milk from an 85-cow year-round calving British Friesian dairy herd, says John Turner, who works on the farm with his father, Anthony, and brother, Guy. The family also runs an engineering and contracting business.
Before conversion, conservation crops consisted of pure ryegrass silage and maize, fertilised with 75t/ha (30t/acre) of FYM. Cows, yielding 6300 litres also ate lt a year of a 20% protein concentrate.
Now the focus is on sustainable forage crops and getting concentrate use down, says John.
"Milk was 24p/litre when we began conversion; now it is 16p. Even if we were not converting to organic we would be looking for more milk from home-produced forage."
Up to 10% of the ration can be non-organic under Soil Association rules, if it is GM-free and from an approved source. Cows receive 2kg a head a day of a 20% protein concentrate which costs £123/t.
"We are looking to reduce this concentrate level as far as possible by feeding high protein forages," says John.
Boosting forage protein has involved establishing protein leys which cows have grazed efficiently over summer, says Guy. "Not using fertiliser nitrogen seems to make grass more palatable. Cows used to clean up well during the first grazing but now this is happening with subsequent grazings too."
The farms worst existing leys were taken out and new replacement leys containing 30-40% white clover cost £125/ha (£50/acre) to cultivate and £80/ha (£32/acre) for seed, says John. "This did bring savings on fertiliser nitrogen and the benefit of improved forage quality but these are difficult to quantify."
Ryegrass conservation leys have been replaced with a 60% ryegrass, 40% red clover mixture and have provided four silage cuts. "Yields were slightly down for first cut which was taken late on June 7 this year. We used to get 15t/acre whereas this year it was closer to 12.5t/acre.
"But sward recovery was exceptional and we had a second cut of 5t/acre and third and fourth cuts as well."
Previously, despite applications of 452kg/ha (360 units/acre) of fertiliser nitrogen over the season, the family was lucky to get a second cut, says Anthony. "We have a low rainfall of 18in a year, which means recovery of pure grass swards was poor. But red clover copes better in dry conditions."
Analysis of silage shows it is 35% dry matter, 12% crude protein, and 11.4 ME with a D-value of 71.4. Although protein is not exceptionally high, John is hoping that it will feed well. "The intake equation predicts high levels of intake and there should be little waste."
Producing enough home-grown energy is perhaps the biggest challenge facing the farm. Maize – which used to account for 50% of cows winter forage intake – has failed to thrive under organic conditions, says John.
"We grew a trial plot of organic maize last year, but were only allowed to apply 10t of FYM instead of the usual 30t. Black nightshade also invaded the crop. Plants grew to only one third of their usual height and produced spindly cobs.
"We have now stopped growing maize, which was a difficult decision to come to as it has formed the mainstay of our winter feeding programme for 30 years."
Peas have proved a more reliable crop to grow in an organic system with the added benefit that they are a nitrogen-fixing crop, he says. "But they are lower yielding than maize, producing 8-10t/acre of whole-crop compared with 16-18t/acre for maize. Also we are growing protein rather than starch."
Cereals are likely to offer the most promising solution to the energy deficit this winter, believes herdsman, John Russell. "For higher yielding cows we will feed grass silage and pea and wheat whole-crop plus 2kg a day of barley topped up with a high protein concentrate. It will take a while to work out optimum concentrate levels but will be difficult to stop using it altogether and maintain yield."
Red clover leys have provided four silage cuts for John Turner (left) and brother, Guy, this year.
• Clover and peas boost protein.
• Organic maize difficult.
• Energy a challenge.