BACKGROUND Information on the nutritive value, dry matter (DM) digestibility and methane (CH4 )-emission potential of the grass species are required for their optimal utilization in ruminant rations. The present study was designed: (i) to quantify the nutrient profile, mineral composition and in vitro dry matter digestibility (IVDMD) of winter grass species commonly available in Northern Pakistan; and (ii) measure the in vitro gas production (IVGP) and CH4 emission of the grass species during 72 h in vitro ruminal fermentation. Seven grass species, namely, Cenchrus ciliaris, Setaria anceps, Panicum antidotale, Panicum maximum, Pennisetum purpureum, Pennisetum orientale and Atriplex lentiformis were assessed. RESULTS Large variability (P < 0.001) was observed among grass species for the contents of all measured nutrients, IVDMD, IVGP and CH4 -production. Notably, the content (g kg-1 DM) of crude protein varied from 59.8 to 143.3, neutral detergent fibre from 560.3 to 717.9, IVDMD from 375.1 to 576.2, and 72 h cumulative IVGP from 97.6 to 227.4 mL g-1 organic matter (OM) and CH4 from 48 to 67 mL g-1 OM. Among the grasses, P. antidotale had greater content (g kg-1 DM) of CP (143.3), IVDMD (576.2), 72 h cumulative IVGP (227.4 mL g-1 OM) and produced smallest amount of total CH4 (48 mL g-1 OM) during 72 h fermentation. In contrast, A. lentiformis had smallest content (g kg-1 DM) of CP (59.8), IVDMD (375.1), 72 h cumulative IVGP (97.6 mL g-1 OM) and produced greater amount of total CH4 (67 mL g-1 OM) during 72 h fermentation. CONCLUSION The findings of current study highlight that, it is possible to select and further develop grass species with high nutritional value and lower CH4 -production, which can improve livestock productivity, farms profitability, and long-term environment sustainability. This article is protected by copyright. All rights reserved.

中文翻译：

---

冬季草种的化学成分、瘤胃降解动力学和甲烷生产（体外）

背景 草种的营养价值、干物质 (DM) 消化率和甲烷 (CH4) 排放潜力的信息是它们在反刍动物日粮中的最佳利用所必需的。本研究旨在：(i) 量化巴基斯坦北部常见冬草的营养成分、矿物质成分和体外干物质消化率 (IVDMD)；(ii) 在体外瘤胃发酵 72 小时期间测量草种的体外产气量 (IVGP) 和 CH4 排放量。评估了七种草种，即 Cenchrus ciliaris、狗尾草、Panicum antidotale、Panicum maximum、Pennisetum purpureum、Pennisetum orientale 和 Atriplex lentiformis。结果 在所有测量的养分、IVDMD、IVGP 和 CH4 生产。值得注意的是，粗蛋白的含量（g kg-1 DM）从59.8到143.3不等，中性洗涤纤维从560.3到717.9，IVDMD从375.1到576.2，72 h累积IVGP从97.6到227.4 mL g-1有机物（ OM) 和 48 至 67 mL g-1 OM 的 CH4。在草中，P. antidotale 的 CP (143.3)、IVDMD (576.2)、72 h 累积 IVGP (227.4 mL g-1 OM) 的含量较高 (g kg-1 DM)，产生的 CH4 总量最小 (48 mL g-1 OM) 在 72 小时发酵期间。相比之下，A. lentiformis 的 CP (59.8)、IVDMD (375.1)、72 小时累积 IVGP (97.6 mL g-1 OM) 的含量最低 (g kg-1 DM) 并产生更多的总 CH4 (67 mL g -1 OM) 在 72 小时发酵期间。结论 目前的研究结果强调，可以选择并进一步开发具有高营养价值和低 CH4 产量的草种，这可以提高牲畜生产力、农场盈利能力和长期环境可持续性。本文受版权保护。版权所有。