Context Finishing lambs on pasture and specialist forages is a commonly used production system in southern Australia; however, there is little information properly comparing multiple pasture options for lamb production. Aim We aimed to compare growth rates of lambs when grazing traditional pastures, novel legumes, or a herb–legume mixture. Methods Six pasture and forage treatments were sown in three replicate 0.4-ha plots and with access to irrigation. Treatments were French serradella (Ornithopus sativus Brot.), bladder clover (Trifolium spumosum L.), forage brassica (Brassica napus L.), lucerne (Medicago sativa L.), lucerne + phalaris (Phalaris aquatica L.), and arrowleaf clover (Trifolium vesiculosum Savi) + chicory (Cichorium intybus L.). The last two treatments were sown in a 1 : 1 alternate sowing-row (tyne) arrangement. All plots were grazed concurrently from 15 October to 2 December 2014, each plot with a mixed-sex group of 13 weaned lambs: five White Dorper, three White Suffolk × White Dorper and five White Suffolk × Merino lambs. During the grazing period, lambs were weighed each week following an overnight curfew. Starting liveweight (mean ± s.d.) was 32.4 ± 5.5 kg. At the completion of the grazing period, lambs were slaughtered and carcass traits recorded. Key results Lambs grazing arrowleaf clover + chicory had the highest average daily growth rates (ADG) (245 g/lamb.day) and those grazing lucerne + phalaris the lowest (119 g/lamb.day). There was a lag in ADG for the forage brassica treatment over the first 14 days of grazing, and lamb growth plateaued for the bladder clover treatment toward the end of the trial. Overall, ADG for the forage brassica and bladder clover treatments was similar to that for lucerne. Lambs grazing French serradella had similar ADG to 18 November compared with those grazing other treatments, except arrowleaf clover + chicory; however, lambs grazing French serradella were withdrawn from the experiment on 26 November after losing weight. The genotype × treatment interaction was significant for final liveweights, with White Suffolk × White Dorper lambs having higher predicted final liveweight on the arrowleaf clover + chicory pasture (45.2 kg) than White Dorper (43.8 kg) and White Suffolk × Merino (44.0 kg) lambs, and higher liveweight on lucerne than White Suffolk × Merino lambs (42.6 vs 41.4 kg). White Dorper lambs had a higher overall sale value owing to their higher dressing percentage. The proportion of lambs reaching the finished weight target was higher for arrowleaf clover + chicory (0.96) than for any other treatment. Conclusions and implications Using a forage option that maintains high levels of production and quality later in spring can increase the proportion of lambs reaching target weights and the final sale weight of lambs.

中文翻译：

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澳大利亚南部春季放牧传统和新型牧场的白杜泊羔羊和杂交羔羊的羔羊生长率和胴体特征

背景 在牧场和专业草料上对羔羊进行精整是澳大利亚南部常用的生产系统；然而，很少有信息正确比较羔羊生产的多种牧场选择。目的 我们旨在比较放牧传统牧场、新型豆类或草本-豆类混合物时羔羊的生长率。方法 在 3 个重复的 0.4 公顷地块上播种 6 种牧草和牧草处理，并可以灌溉。处理为法国小叶草 (Ornithopus sativus Brot.)、膀胱三叶草 (Trifolium spumosum L.)、牧草芸苔 (Brassica napus L.)、苜蓿 (Medicago sativa L.)、苜蓿 + phalaris (Phalaris Aquatica L.) 和箭叶三叶草(Trifolium v​​esiculosum Savi) + 菊苣 (Cichorium intybus L.)。最后两个处理以 1:1 交替播种行（泰恩）排列播种。2014 年 10 月 15 日至 12 月 2 日期间，所有小区同时放牧，每个小区有 13 只断奶羔羊的混合性别组：五只白杜泊、三只白萨福克 × 白杜泊和五只白萨福克 × 美利奴羊。在放牧期间，在宵禁后每周称重羔羊。起始体重（平均值±标准差）为 32.4±5.5 公斤。在放牧期结束时，宰杀羔羊并记录胴体性状。主要结果 放牧箭叶三叶草 + 菊苣的羔羊平均日增长率 (ADG) 最高（245 克/羔羊.天），而放牧苜蓿 + 灯笼草的羔羊最低（119 克/羔羊.天）。在放牧的前 14 天，牧草芸苔治疗的 ADG 存在滞后，而在试验结束时，膀胱三叶草治疗的羔羊生长趋于稳定。全面的，牧草芸苔和膀胱三叶草处理的 ADG 与苜蓿相似。与放牧其他处理的羔羊相比，放牧法国 serradella 的羔羊的 ADG 与 11 月 18 日相似，但箭叶三叶草+菊苣除外；然而，在 11 月 26 日，放牧法国 serradella 的羔羊在减肥后退出了实验。基因型 × 处理相互作用对最终活重很重要，白萨福克 × 白杜泊羔羊在箭叶三叶草 + 菊苣牧场（45.2 公斤）上的预测最终活重比白杜泊（43.8 公斤）和白萨福克 × 美利奴羊（44.0 公斤）高羔，并且苜蓿的活重高于白萨福克 × 美利奴羔羊（42.6 对 41.4 公斤）。白杜泊羔羊的整体销售价值较高，因为它们的屠宰率较高。箭叶三叶草 + 菊苣达到最终体重目标的羔羊比例 (0.96) 高于任何其他处理。结论和影响 使用在春季晚些时候保持高水平生产和质量的草料选择可以增加达到目标体重的羔羊比例和羔羊的最终销售重量。