Lupins offer poultry producers an alternative to soya

Raw material pricing has become an increasingly hot topic in the poultry sector in recent years, with cereals and soya meal characterised by volatility.

Add to this the environmental concerns of using soya imported primarily from South America, and lupins stand out as an interesting alternative.

Lupins are a pulse crop, which can be grown in the UK. They have a similar nutritional profile to soya, providing both protein and energy, and initial trial work with laying hens has highlighted their potential.

Worldwide the biggest producer of lupins is Australia where over 1m tonnes are produced each year. France and Russia are also significant growers.

While white lupins are fed to ruminants, using sweet lupins in poultry diets is a relatively new idea in Europe. However, in Australia there is an established market for this crop, for both broilers and laying hens.

University research

Lupins in UK Agriculture and Aquaculture* (LUKAA) is a project which aims to develop this sustainable protein source for all livestock.

Part of the work has involved laying hen studies at the Institute of Biological, Environmental and Rural Sciences (IBERS) at Aberystwyth University, led by Prof Nigel Scollan, where soya was partially replaced with lupins.

Yellow and narrow-leafed (blue) lupins were chosen, as they contain lower levels of anti-nutritional factors (ANFs). Point of lay hens were fed one of four diets for 18 weeks, their performance monitored and egg quality recorded.

All the rations contained 15-16% protein with an energy value of 11.4MJ/kg. The control diet was a standard soya-based layers mash, and lupins were included at 150g/kg in each of the trial diets. They were incorporated either whole, de-hulled, or de-hulled with Synergen – a solid-state fermentation product known to improve nutritional availability.

In the trial with yellow lupins, there were significant differences in terms of dry matter (DM) intake and yolk redness (see Table 1).

Birds fed the diet containing Synergen had a lower DM intake, but with no decrease in bird weight or egg production, indicating an economic benefit. The increase in yolk pigmentation could be due to the higher carotenoid content of lupins compared with soya.

Prof Scollan has been encouraged by the positive responses. “Lupins can be successfully fed to laying hens without compromising performance or egg quality,” he concludes.

Previously it was thought that de-hulling lupins was necessary, due to the ANF and fibre content of the hulls. However, this study demonstrates that this costly process is not required for these species of lupin.

Yellow lupins have higher protein content than narrow leafed (blue) lupins and performed better in the studies.

Field trials

Following the success of the university work with lupins, it was decided to put them to the test in a commercial laying flock.

Egg producer/packer Birchgrove, near Aberystwyth in west Wales, is a free-range business which takes sustainability seriously. Its hens are kept to Freedom Food standards and owner Tony Burgess is actively involved in offsetting carbon emissions.

Mr Burgess first became interested in alternatives to soya as a way of reducing the food miles of his eggs. He feels that importing raw materials large distances is neither ethical nor sustainable. “By using home-grown crops we are not only improving food security, but are also supporting arable farmers.

“Lupins make sense to me. They have an excellent nutritional profile, are nitrogen fixing and can be grown locally.”

The commercial evaluation he carried out exceeded his expectations.

One shed, containing 3,000 hens, was fed a diet containing yellow lupins for 18 weeks. Lupins were included at 150g/kg, replacing up to 30% of the soya in the diet. The performance of the Bovan Brown hens was compared with that of previous cycles from the same house.

The birds fed the lupin ration performed the same as, if not better than, those who had eaten a standard wheat/soya ration. Body weight was maintained and egg production was the same at week 37.

Whole lupins have a significantly higher fibre level than soya beans. There has been much research carried out into the benefits of fibre for poultry, in terms of gastro-intestinal health. Fibre slows the transit of food in the birds’ gut, improving digestion and allowing more nutrients to be absorbed.

This can both improve performance and reduce physiological stress to the birds, including reduced pecking. This was certainly the case at Birchgrove, with 100% feather cover. Another interesting observation, which mirrored the findings at IBERS, was the increase in yolk pigmentation.

Mr Burgess says his experience of the trial “has transformed my thoughts on the potential of lupins to feed laying hens”.

Table 2. Evaluation of lupins in layer stock
Average values
	% Production			Body	Egg	Feed
				weight (g)	weight (g)	consumption (g)
	wk20	wk24	wk37	wk37	wk37	wk37
2012 Data	86	86	90	1935	64	125
2013 Lupin trial	82	90	90	1950	66	117

Growing considerations

Lupins are a legume, which means they have nitrogen-fixing bacteria on their root nodules. By fixing nitrogen from the soil, they reduce fertiliser usage, saving up to £75/ha. They are a useful spring-grown break crop for arable farmers, also offering weed control.

Lupins are a flowering plant, which produce protein-rich grains, also known as pulses. However, they have higher protein (30-45%) and oil (5-7%) levels than their more common relatives. This makes them a viable home-grown alternative to the most internationally important pulse, soya.

But they still need to justify their place in the arable rotation.

The crops currently grown in the UK only yield up to 3.5t/ha. Increasing yield, reducing variability and improving the tolerance to alkaline soils are priorities to make growing lupins profitable.

Despite this, Richard Flack from feed manufacturer Wynnstay believes that the time is approaching when lupins will justify their place in the diets of laying hens. Economically, if the product were available in sufficient volume, it would already feature in organic or non-GM diets – as the price of this kind of soya has gone through the roof and availability is not assured, he suggests.

“For conventional rations, there are still some hurdles to overcome, but with varietal improvements, there is no reason why we won’t be using more lupins in poultry diets in the future,” says Mr Flack.

*The LUKAA project is an industry led and funded project involving 10 industrial partners, two research institutes and is co-funded by the Technology Strategy Board (TSB) in collaboration with the BBSRC.