Could whole-crop peas be the next revolution in forage for dairy cow diets.
Carol McLaren finds out how one Scottish producer fared with a crop last year
WHOLE-CROP peas have made an impressive debut on a Dumfriesshire dairy unit. The crop has established itself as a hassle-free, low-cost source of quality, home-grown protein, despite atrocious weather at harvest last July.
Feeding whole-crop peas this winter has seen milk quality improve in the high yielding Holstein cows at Robert Kirkwoods 200-head unit at Mouswald Grange, where concentrate use has gone down 2-3kg/head.
Last year, 15ha (38 acres) of Espace peas were sown on spare acres after the farm lost its sheep flock due to foot-and-mouth culls. Mr Kirkwood is unconvinced about growing maize under plastic in south-west Scotland, but whole-crop peas have done well and this year he now intends to grow 22ha (55 acres) and try a few more varieties.
"We couldnt have had a worse harvest and grass silage would have been a disaster, but the peas have given us good fodder," says Mr Kirkwood.
"The variety yielded well at about 12t fresh/acre. Despite a little lodging, the crop was easy to grow, with no need for weed sprays or fertiliser, and early harvesting allowed us access to get the next crop in. Nitrogen was also present to help it establish."
At harvest, the clamp was layered with one-third whole-crop peas, one-third whole-crop barley and one-third grass silage. It is being fed ad-lib to high yielders, with daily intakes at about 10kg freshweight. Cows also receive about 10kg of fodder beet/head.
Cows find the whole-crop peas extremely palatable and would "eat them before anything else", says Mr Kirkwood.
The rise in the popularity of whole-crop peas is likely to continue, believes Johnny Bax, technical manager of additive manufacturer Biotal.
Last year the area grown in the UK more than doubled, with peas proving a flexible, unproblematic option. Producers in the east and west also reported milk yield increases in high and low yielding herds.
"Peas are the most reliable option for protein, offering a cheap source of high quality forage," says Mr Bax.
"Whole-crop peas are proving popular with dairy and beef producers. The latter tend to feed peas at rearing stage and finish stock on whole-crop cereals, although some are feeding peas all the way through."
For dairy cows, at least 10kg freshweight is required in diets to see a yield increase. One 10,800 litre herd reports a 300 litre/cow production increase entirely attributable to the switch to peas, he adds.
"The main attraction is its a one cut crop, quick-growing – in 12-15 weeks depending on the area – and it offers a god yield potential of 8-10t of DM/ha.
"Providing the whole-crop is cut at the right stage, it can offer a good source of quality protein with good fibre and starch levels depending on the timing of cutting."
• Grow in 12-15 weeks.
• Yield 8-10t DM/ha.
• High protein crop.
Last year the area of whole-crop peas harvested in the UK doubled, says Johnny Bax.