Use of varying combinations of energy and protein sources as supplementary feed for lambing ewes grazing cereal stubble

Abstract

Summary. Three feeding trials compared production of lambing ewes grazing stubbles and fed different combinations of energy and protein supplements as loose licks. Each experiment had 2 treatments in a 2 x 2 factorial design. Experiment 1 compared urea (12.5 g/ewe. day) with fish meal (100 g/ewe. day) when fed with molasses (100 g/ewe. day) for 38 days during late pregnancy. Fish meal increased liveweight gain (from 2.0 to 5.7 kg) and wool growth (20%) but urea had no effect. In experiment 2, urea (12.5 g/ewe. day) was fed in combination with molasses (200 g/ewe. day) or barley meal (200 g/ewe. day) for 63 days during late pregnancy (last 6 weeks) and early lactation. Ewes supplemented with the barley–urea combination gained 5.6 kg during the last 6 weeks of pregnancy compared with 0.40 kg for barley and the 1.02 and 1.34 kg weight loss for ewes receiving molasses and the molasses–urea combination, respectively. Experiment 3 compared urea (12.5 g/ewe. day) with sweet lupin meal (106 g/ewe. day) when fed with barley meal (200 g/ewe. day) for 56 days during late pregnancy (last 4 weeks) and lactation. Sweet lupin meal improved the liveweight change of ewes during pregnancy (from 160 to 200 g/ewe. day) as well as the birth weight of lambs (400 g) but urea had no effect. The performance of lambing ewes grazing low-quality pasture at a high stocking density (>4.5 ewes/ha) for a long period (>130 days) can be improved by relatively low amounts of supplements such as fish meal, sweet lupin meal and barley–urea.