Lupins offer potential as a soya replacement in lamb finishing rations
Take Home Message: The inclusion of home grown lupins in lamb finishing rations will result in a similar level of performance as those fed soyabean meal.
Both narrow-leaf and yellow lupins could be used as a home-grown alternative to imported soya, or a bought-in commercial concentrate containing rapeseed meal and palm kernel, for finishing lambs in the UK without any adverse effects on lamb productivity or carcass killing-out percentages.
That was the conclusion of a study, carried out by scientists at the Institute of Biological, Environmental and Rural Sciences at Aberystwyth University, which was shared with delegates at this year’s British Society of Animal Science’s annual conference.
Soya bean meal is an important component of animal feed and oil seed rape and palm kernel cake and meal are typically used in commercial concentrate diets for sheep in the UK.
Lupins, as a high protein and high energy nitrogen-fixing grain legume, have potential as a home-grown livestock feed in the UK. And research has been conducted on the effects of narrow-leafed lupins. “But there have been few studies on the effects of yellow lupins when fed to sheep,” said Christina Marley, explaining the rational behind her team’s work.
Their study investigated the effects of incorporating yellow lupins, narrow-leaf lupins or soya bean meal into the concentrate diets of finishing lambs on lamb productivity and carcass characteristics when compared to a commercial UK lamb finisher diet.
The experiment comprised a lamb finishing experiment, using 80 male castrated Suffolk-cross lambs – 20 lambs on four different dietary treatments. Treatments were narrow-leafed lupin, yellow lupin, soya bean meal and a commercial (control) lamb finisher diet.
The concentrate diets (pelleted) had a target nitrogen concentration of 25.7g/kg DM (16% CP) and ME of 11.0 MJ/kg DM. The two lupin varieties for the experiment were produced on the same experimental site (at IBERS) and harvested according to standard practice.
The dry matter content of the concentrate diets were 859, 850, 867 and 874g/kg freshweight for the soya bean meal, narrow leaf lupin, yellow lupin and control diet, respectively. The nitrogen concentration of the soya bean meal, narrow-leaf lupin, yellow lupin and control diet was 32.2, 32.9, 33.4 and 30.8g/kgDM, respectively. And the ME concentration of the soya bean meal, narrow-leaf lupin, yellow lupin and control diet was 12.5, 12.8, 12.6 and 12.6 MJ/kgDM, respectively.
“And we found that there was no significant effect of dietary treatment on the liveweight gain of lambs offered the different diets,” said Dr Marley. The liveweight gain of lambs offered concentrates incorporating soya, narrow-leaf lupin, yellow lupin or a commercial control diet were 185, 229, 193 and 166g/d, respectively,” she added.
Presented to the British Society of Animal Science Annual Meeting, March 30 to April 1, 2009, Southport, UK.
Full details: Marley CL, Fychan R, Theobald VJ, Davies DRW, Sanderson R, Abberton MT, Davies DR: “The effect of incorporating either lupins or soya bean meal into concentrate diets when compared with a control concentrate diet on the performance and carcase characteristics of finishing lambs.”
Summary (pdf) Presentation_052marley (pdf)
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