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Context: Economic modelling identified that mating of ewe lambs for lambing at 1 year of age has the potential to increase the profitability of sheep-production systems in south-western Victoria. In order to optimise reproductive rates, ewe lambs should weigh at least 35–40 kg, have a condition score (CS) of 3.0 at mating, and be gaining weight (100–150 g/day) during mating. However, typical perennial ryegrass (Lolium perenne L.) pastures in south-west Victoria do not support the attainment of these targets without additional supplementation. Aim: Our research aimed to determine how grazing summer-active pastures or brassica (Brassica napus L.) forages affects the liveweight, CS, conception and reproductive rate of ewe lambs when offered before and during mating compared with a system using perennial ryegrass plus supplement. Methods: A field experiment was conducted at Hamilton, Victoria, Australia, in 2014 and 2016 testing seven forage treatments replicated four times in a complete block design. The treatments were: canola (B. napus , two treatments of different cultivars), forage brassica, lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.) and perennial ryegrass. Key results: Ewe lambs grazing canola or forage brassica had higher (P < 0.05) liveweight gains during the pre-mating and mating periods than those grazing the perennial ryegrass treatment (148 vs 75 g/day in 2014, s.e.m. 17; 139 vs 54 g/day in 2016, s.e.m. 17). In 2014, spring-sown dual-purpose canola, lucerne and chicory resulted in higher (P < 0.05) reproductive rates (144–151%) than the perennial ryegrass treatment (103%); forage brassica and plantain gave intermediate results (128% and 129%). Conclusion: Brassica forages (including spring-sown canola), lucerne and chicory can support the attainment of key liveweight and CS targets for successful mating of ewe lambs in autumn. Implications: Spring-sown canola is therefore a viable alternative forage for use by livestock producers in southern Australia and presents an opportunity to incorporate an alternative income stream in mixed-farming systems. Mating of ewe lambs for lambing at 1 year of age has the potential to increase the profitability of sheep-production systems; however, successful mating of ewe lambs requires that they have reached a bodyweight of 35–40 kg, have a condition score of at least 3.0, and be gaining weight before and during mating. Grazing dual-purpose canola crops during summer and autumn enables ewe lambs to meet these targets and improves liveweight gains and reproductive performance relative to traditional perennial ryegrass pastures. The implications are a more productive ewe flock, and a flock that produces more lambs over the duration of a ewe's lifetime. [ABSTRACT FROM AUTHOR]

Context: Filling the summer–autumn feed gap is a key priority for sheep producers in southern Australia's high-rainfall zone. Aim: Our research aimed to determine whether spring-sown winter-type canola (Brassica napus L.) could increase herbage mass and nutritive characteristics during summer and autumn relative to other forage options in southern Australia's HRZ. Methods: A field experiment was conducted at Hamilton, Victoria, Australia, in 2014 and 2016 testing seven forage treatments replicated four times in the complete block design. The treatments were: canola (two treatments of different cultivars), forage brassica (B. napus), lucerne (Medicago sativa L.), chicory (Cichorium intybus L.), plantain (Plantago lanceolata L.) and perennial ryegrass (Lolium perenne L.). Key results: Herbage mass and nutritive characteristics of the canola varieties did not differ (P > 0.05) from forage brassica. Herbage mass in March 2014 was 3.35–3.64 t dry matter (DM)/ha for brassicas; 1.05–1.37 t DM/ha for perennial ryegrass, plantain and chicory; and 2.94 t DM/ha for lucerne (P < 0.001, l.s.d. = 1.20). In March 2016, herbage mass was 1.86–2.05 t DM/ha for brassicas and 2.14–2.49 for the other forage treatments (P < 0.05; l.s.d. = 0.47). Brassicas had higher (P < 0.05) metabolisable energy (ME) concentrations and lower (P < 0.05) neutral detergent fibre (NDF) concentrations on most sampling dates than chicory, plantain, lucerne and perennial ryegrass. The crude protein (CP) concentration of the brassica treatments was not different (P > 0.05) from that of the other forage treatments. Concentrations of ME, CP and NDF were very similar between years for the brassicas, with March ME, CP and NDF concentrations of 12.0–13.2 MJ/kg DM, 14.0–20.1% DM and 16.7–23.6% DM. Conclusion: Canola provided increased or equivalent levels of herbage mass and nutritive characteristics compared with other forage options in south-western Victoria on most, but not all, sampling dates. However, the annual spring-sowing requirement is a challenge under variable spring-rainfall conditions and may limit productivity if there is poor establishment. Implications: Spring-sown canola is a viable alternative forage for livestock producers and offers a potential second income stream in high-rainfall-zone livestock farming systems. Filling the summer–autumn feed gap is a key priority for sheep producers in southern Australia's high-rainfall zone, with summer and autumn traditionally being a time of feed shortage for livestock production. Winter-type canola can produce up to 3.5 t/ha of high-quality feed for grazing livestock during this key summer–autumn period. This provides livestock producers with the opportunity to increase production during this time of year, which could involve finishing livestock to higher slaughter weights or increasing the reproductive performance of ewes, utilising forage rather than purchasing supplementary feeds. [ABSTRACT FROM AUTHOR]