The objective of this study was to determine the effect of different concentrations of rice straw (RS) and purple corn stover (PCS) treated with Volvariella volvacea fed in total mixed rations (TMR) on ruminal fermentation, blood metabolites, calculated methane (CH₄) production, and milk fatty acid profile in mid-lactation crossbred Holstein Friesian cows. The experimental design was a 2 × 2 factorial arrangement of treatments in a 4 × 4 Latin square design. Factor A included roughage type (V. volvacea-treated RS and V. volvacea-treated PCS), and Factor B included roughage (R)-to-concentrate (C) ratio (R:C) (50:50 and 60:40). The four dietary treatment combinations were 1) RS with an R:C ratio of 50:50 (RS50); 2) RS with an R:C ratio of 60:40 (RS60); 3) PCS with an R:C ratio of 50:50 (PCS50); and 4) PCS with an R:C ratio of 60:40 (PCS60). Different roughage sources did not alter total tract digestibility of DM, OM, and NDF (P > 0.05), but PCS increased NDF digestibility by 4.6 percentage units and CP digestibility by 15.6 percentage units. Roughage types influenced rumen propionic acid (C3) concentration 4 h after feeding with PCA increasing higher C3 concentration compared to RS at both R:C ratios. There was no interaction between roughage types and the R:C ratio for CH₄ emission calculated based on volatile fatty acid profiles. However, roughage type impacted CH₄ emission. Calculated CH₄ concentration was lower in PCS than RS. Changing the R:C ratio did not alter milk production, milk composition, or somatic cell count (SCC). Moreover, roughage type did not influence milk production and milk composition, except for SCC which was lower in PCS. Roughage type and the R:C ratio independently influenced milk fat arachidonic acid (C20:4n-6) concentration. Furthermore, the PCS group had higher conjugated linoleic acid (CLA) than the RS groups. The proportion of total C18:0 and cis-9 C18:1 in milk fat increased 10% with the feeding of PCS50 and PCS60. However, milk cis-9, trans-11 C18:2 increased by 61% in the PCS group (P < 0.01). In conclusion, PCS increased rumen C3 and milk fat CLA and arachidonic acid concentration and decreased CH₄ production compared to the RS. The PCS treated with V. volvacea could be used for up to 60% of TMR for dairy cows.

本研究的目的是确定不同浓度的稻草 (RS) 和紫玉米秸秆 (PCS)以全混合日粮 (TMR) 喂养的草菇处理对瘤胃发酵、血液代谢物、计算的甲烷 (CH ₄ ) 泌乳中期杂交荷斯坦弗里斯兰奶牛的产量和乳脂肪酸谱。实验设计是 4 × 4 拉丁方设计中处理的 2 × 2 因子排列。因子 A 包括粗饲料类型（V. volvacea -处理的 RS 和V. volvacea-处理的 PCS），因子 B 包括粗饲料 (R) 与精料 (C) 的比率 (R:C)（50:50 和 60:40）。四种饮食处理组合是：1) RS 的 R:C 比为 50:50 (RS50)；2) R:C 比为 60:40 的 RS (RS60)；3) R:C 比为 50:50 (PCS50) 的 PCS；4) R:C 比为 60:40 (PCS60) 的 PCS。不同的粗饲料来源并没有改变 DM、OM 和 NDF 的总消化道消化率（P > 0.05），但 PCS 使 NDF 消化率提高了 4.6%，CP 消化率提高了 15.6%。饲喂 PCA 后 4 小时，粗饲料类型影响瘤胃丙酸 (C3) 浓度，与两种 R:C 比例的 RS 相比，C3 浓度增加。粗饲料类型与 CH ₄的 R:C 比率之间没有相互作用基于挥发性脂肪酸谱计算的排放量。然而，粗饲料类型影响了 CH ₄排放。PCS 中计算的 CH ₄浓度低于 RS。改变 R:C 比例不会改变牛奶产量、牛奶成分或体细胞计数 (SCC)。此外，粗饲料类型不影响牛奶产量和牛奶成分，除了在 PCS 中较低的 SCC。粗饲料类型和 R:C 比例独立影响乳脂花生四烯酸 (C20:4n-6) 浓度。此外，PCS 组比 RS 组具有更高的共轭亚油酸 (CLA)。随着PCS50和PCS60的加入，总C18:0和顺式-9 C18:1在乳脂中的比例增加了10%。然而，牛奶顺- 9，反-11 C18:2 在 PCS 组中增加了 61% ( P < 0.01)。总之，与 RS 相比，PCS 增加了瘤胃 C3 和乳脂 CLA 和花生四烯酸的浓度，并降低了 CH ₄产量。用草菇处理的 PCS可用于奶牛 60% 的 TMR。