Effect of processed sweet lupin (Lupinus angustifolius) grain supplementation on growth performance and socioeconomic feasibility of Doyogena sheep in Ethiopia

Background The experiment evaluated the effect of supplementing sheep fed natural pasture hay with processed sweet lupin grain on growth performance and its economic feasibility. The finding revealed that use of steamed lupin shown to improve the nutritive value of the grain and sheep performance. Methods The experiment was carried out using 24 yearling lambs with initial body weight of 27.53 ± 2.67 kg (mean ± SD) for 126 days (21 days quarantine, 15 days of adaptation and 90 days growth trial followed by 7 days digestibility trial). The experiment was laid out in a randomised complete block design consisting of four treatments and six blocks. Treatments comprised the feeding of natural pasture hay ad libitum + concentrate mix 440 g (T1), natural pasture hay + 440 g/day roasted, coarsely ground sweet lupin grain (T2), natural pasture hay + 440 g/day sweet lupin grain soaked in water for 72 h (T3), natural pasture hay + 440 g/day steamed sweet lupin grain (T4). Results There was improvements in total dry matter intake and digestibility coefficients of dry matter, organic matter, crude protein, neutral detergent fibre and acid detergent fibre in sheep supplemented with processed sweet lupin grains compared (T4) by 58.49%, 24.66%, 39.39%, 22.97% and 39.68%, respectively, over the control group. Specifically sheep supplemented with T4 had significantly higher (p < 0.001) average daily gain (by 51.04%), feed conversion efficiency (46.34%) and daily weight gain (144.78 g/day) compared to the control treatment, respectively. All processing methods resulted in favourable average daily gain and net return, thus can be employed in feeding systems depending on their availability and relative cost. Conclusions Supplementing sheep fed natural pasture hay with 440 g/day steamed sweet lupin grains improved growth performance and fattening economics of Doyogena sheep compared to T2 (roasted sweet lupin grain), T3 (soaked sweet lupin grain) or the control (T1)