This study aimed to investigate the replacement value of half time grazing of wheat stubbles by vetch, which had been cropped under the context of conservation agriculture (CA). Three grazing treatments were evaluated on Barbarine lambs (initial BW 18 ± 1.42 kg). Treatment 1 consists of 6‐hr grazing on dried vetch only (V). For treatment 2, the sheep were grazing 3 hr on wheat stubbles in morning and 3 hr on dried vetch in the afternoon (VWS). Treatment 3 consists of 6‐hr grazing of wheat stubbles only (WS). At grain maturity stage, biomass yield of vetch averaged 7 tons DM/ha allowing a grazing period of 2 consecutive months. Along this period, vetch conserved its pods indehiscent. Biomass and nutritive value of vetch and wheat stubbles were decreasing from the start to the end of the grazing period. Residual biomass was higher in vetch and wheat stubble assigned to treatment VWS. WS lambs spent more time on walking and standing, while V and VWS lambs allocated more time on biomass uptake. The DM, OM and CP intakes were higher in animal grazing vetch alone or combined to wheat stubble. Rumen fermentation parameters (pH, ammonia nitrogen concentration and protozoa count) were not affected (p > .05) by any of the three treatments. The average daily gain of lambs on V and VWS lambs was three times greater (p < .05) than that of WS lambs (164, 152 and 49.5 g respectively). Cold carcass yield averaged 444, 428 and 388 g/ kg for lambs assigned to V, VWS and WS treatments respectively. It is concluded that grazing vetch alone or combined with WS increased substantially the growth performance and carcass yield of lambs compared with WS grazing only. Therefore, dried vetch grazing could be a solution to make possible mulching and biomass uptake by sheep under the context of CA.

中文翻译：

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保护性农业下干紫云英牧羊放牧的觅食行为、消化和生长性能

本研究旨在探讨保护性农业 (CA) 背景下种植的野豌豆对小麦茬半放牧的替代价值。对 Barbarine 羔羊（初始体重 18 ± 1.42 kg）评估了三种放牧处理。处理 1 仅包括在干紫云英上放牧 6 小时 (V)。对于处理 2，绵羊早上在麦茬上放牧 3 小时，下午在干紫云英 (VWS) 上放牧 3 小时。处理 3 仅包括 6 小时的小麦茬放牧 (WS)。在谷物成熟阶段，野豌豆的生物质产量平均为 7 吨干物质/公顷，允许连续 2 个月的放牧期。在此期间，野豌豆保持其不裂的豆荚。从放牧期开始到结束，野豌豆和小麦残茬的生物量和营养价值呈下降趋势。分配给 VWS 处理的野豌豆和小麦茬中的残余生物量较高。WS 羔羊在行走和站立上花费更多时间，而 V 和 VWS 羔羊在生物量吸收上分配了更多时间。DM、OM 和 CP 摄入量在动物放牧紫云英单独或与小麦残茬结合时较高。瘤胃发酵参数（pH、氨氮浓度和原生动物数）不受影响（p  > .05) 通过三种处理中的任何一种。V 和 VWS 羔羊羔羊的平均日增重是 WS 羔羊（分别为 164、152 和 49.5 克）的三倍（p <  .05）。对于分配到 V、VWS 和 WS 处理的羔羊，冷胴体平均产量分别为 444、428 和 388 g/kg。结论是，与仅放牧 WS 相比，单独放牧紫云英或与 WS 结合显着提高了羔羊的生长性能和胴体产量。因此，干野豌豆放牧可能是在 CA 背景下使绵羊覆盖和生物量吸收成为可能的解决方案。