Legume Crops as Protein Alternatives
Protein in the form of purchased concentrates is perhaps the most expensive feed on farms today. This has driven increased interest in alternative lower cost forages from more sustainable sources.
There are only limited options available in this vein locally, and all of these come from legume crops. The main choices are field beans, peas or lupins for wholecrop, normally in mixtures, and red clover as silage.
Field beans have been grown for many years in Northern Ireland. Sown from February through to April, they provide a source of protein which can be fed to all ruminant livestock. They fix their own nitrogen, act as a break crop in a cereal rotation and leave residual nitrogen for the following crop. Combined from mid-September onwards with yields in the region of 5 tonnes per hectare, protein of the crop is in the region of 30% and can be dried or treated with propionic acid.
We have experience with peas and lupins in mixtures with oats, barley, wheat and triticale for wholecrop. This produces a protein content of around 12-14% compared to 8-9% with a straight cereal wholecrop and a lower total starch. These mixes have been fed to both beef animals and dairy cows with better results than the feed analysis would have suggested.
Red clover was widely used back in the sixties and seventies but then fell out of favour. However it does offer one of the best alternative protein options since, unlike lucerne which requires light, free draining, high ph soils, it can be grown on a wide range of soil types.. Red clover is best used as a silage crop with 3-4 cuts taken each year and the possibility of aftermath grazing with lambs or beef animals. Yields produced can be approximately of 11/12 tonnes DM per hectare and a protein of 15-19%.
It is preferable to sow red clover between April and August with a soil ph of 6.0 and potash and phosphate indexes at 2+. Red clover is normally sown in mixtures with Italian or hybrid ryegrass. The advent of new more persistent varieties like AberClaret, which lasts up to 4/5 years, makes it ideal for combining with high yielding varieties of hybrid ryegrass. Crops should be ensiled at 25-35% DM but not over wilted as this leads to leaf shatter and reduced quality. A suitable additive should always be used as red clover has a high buffering capacity and a rotation is required with 5-6 years between crops.
All of these alternatives can offer a means to reduce the cost of purchasing protein on the farm. Start with an area and build up some experience with the crop that fits your farm system best.