Animal and Veterinary Sciences, School of Food and Agriculture, University of Maine, Orono, ME 04469, USA.
Department of Animal Sciences, Federal University of Lavras, Lavras, MG 37200, Brazil.
J Anim Sci. 2022 May 1;100(5). doi: 10.1093/jas/skac095.
This study evaluated the effects of chemical and biological preservatives and ensiling stage on spoilage, ruminal in vitro fermentation, and methane production of wet brewer's grain (WBG) silage. Treatments (TRT) were sodium lignosulfonate at 10 g/kg fresh WBG (NaL1) and 20 g/kg (NaL2), propionic acid at 5 g/kg fresh WBG (PRP, 99%), a combination inoculant (INO; Lactococcus lactis and Lactobacillus buchneri each at 4.9 log cfu per fresh WBG g), and untreated WBG (CON). Fresh WBG was treated and then ensiled for 60 d, after which mini silos were opened and aerobically exposed (AES) for 10 d. Data were analyzed as an RCBD (five blocks) with a 5 TRT × 3 stages (STG; fresh, ensiled, and AES) factorial arrangement. Results showed that ensiled PRP-treated WBG markedly preserved more water-soluble carbohydrates and starch than all other ensiled TRT (P < 0.001). Dry matter losses of ensiled PRP-treated WBG were 48% lower than all other ensiled TRT (P = 0.009) but were not different than CON in AES (P = 0.350). Due to its greater concentration of digestible nutrients, PRP-treated AES was less aerobically stable than CON (P = 0.03). Preservation was not improved by INO, NaL1, or NaL2 but the latter prevented the increase of neutral detergent fiber across STG (P = 0.392). Apparent in vitro DM digestibility (IVDMD) decreased only in ensiled CON, INO, and NaL1 relative to fresh WBG and AES NaL2 had greater IVDMD than all other AES TRT (P ≤ 0.032). In vitro ruminal fermentation of fresh WBG resulted in a greater methane concentration and yield than the other STG (P < 0.033). In conclusion, PRP was the most effective at preserving WBG during ensiling but failed to improve aerobic stability under the conditions tested.
本研究评估了化学和生物防腐剂以及青贮阶段对湿啤酒糟（WBG）青贮饲料变质、瘤胃体外发酵和甲烷产生的影响。处理（TRT）分别为 10 g/kg 新鲜 WBG 的木质素磺酸钠（NaL1）和 20 g/kg（NaL2）、5 g/kg 新鲜 WBG 的丙酸（PRP，99%）、组合接种剂（INO；每克新鲜 WBG 含有 4.9 对数 CFU 的乳球菌和布氏乳杆菌）和未处理的 WBG（CON）。新鲜 WBG 经处理后青贮 60 天，然后打开小型青贮窖并在有氧条件下暴露（AES）10 天。数据采用 RCBD（五个块）分析，具有 5 个 TRT×3 个阶段（STG；新鲜、青贮和 AES）的因子排列。结果表明，与所有其他青贮 TRT 相比，青贮 PRP 处理的 WBG 显著保留了更多的水溶性碳水化合物和淀粉（P < 0.001）。青贮 PRP 处理的 WBG 的干物质损失比所有其他青贮 TRT 低 48%（P = 0.009），但在 AES 中与 CON 无差异（P = 0.350）。由于其更高浓度的可消化养分，PRP 处理的 AES 比 CON 更容易有氧不稳定（P = 0.03）。INO、NaL1 或 NaL2 并未改善保存效果，但后者阻止了中性洗涤剂纤维在 STG 中的增加（P = 0.392）。与新鲜 WBG 和 AES NaL2 相比，仅在青贮 CON、INO 和 NaL1 中观察到体外 DM 消化率（IVDMD）降低（P ≤ 0.032）。新鲜 WBG 的体外瘤胃发酵导致甲烷浓度和产量高于其他 STG（P < 0.033）。总之，PRP 在青贮过程中最有效地保存 WBG，但在测试条件下未能提高有氧稳定性。
