Department of Animal Sciences, The Ohio State University, Wooster, OH 44691, USA.
J Anim Sci. 2012 Nov;90(11):3905-13. doi: 10.2527/jas.2011-5059. Epub 2012 Jun 4.
Two experiments were conducted to evaluate the effects of monensin and dried distillers grains with solubles (DDGS) on ruminal metabolism in 8 fistulated steers. In Exp. 1, treatments were (DM basis): 1) 0 mg monensin/kg diet DM, 2) 22 mg monensin/kg diet DM, 3) 33 mg monensin/kg diet DM, and 4) 44 mg monensin/kg diet DM. The remainder of the diet was 10% corn silage, 60% DDGS, 10% corn, and 20% mineral supplement that used ground corn as the carrier. There was no effect (P > 0.80) of dietary monensin inclusion on DMI. Increasing dietary monensin did not affect (P > 0.05) ruminal VFA concentrations or lactic acid concentrations. There was no effect (P > 0.15) of increasing dietary monensin concentration on ruminal hydrogen sulfide gas (H(2)S) and liquid sulfide (S(2-)) concentrations, or ruminal pH. In Exp. 2, treatments were arranged in a 2 × 2 factorial and contained (DM basis): 1) 0 mg monensin/kg diet DM + 25% DDGS inclusion, 2) 0 mg monensin/kg diet DM + 60% DDGS inclusion, 3) 44 mg monensin/kg diet DM + 25% DDGS inclusion, and 4) 44 mg monensin/kg diet DM + 60% DDGS inclusion. The remainder of the diet was 15% corn silage, corn, and 20% mineral supplement that used ground corn as a carrier. With 60% dietary DDGS inclusion, DMI decreased (P < 0.01) when compared with 25% DDGS inclusion. With 25% DDGS in the diet, 0 h postfeeding acetate concentration was decreased compared with when 60% DDGS was fed (P < 0.01). A similar response (P < 0.01) occurred for total VFA concentrations at 0 h postfeeding. However, at 3 and 6 h postfeeding, propionate concentrations increased (P ≤ 0.05) in cattle fed the 60% DDGS diets, regardless of monensin inclusion. This increase in propionate concentrations contributed to the increase (P = 0.03) in total VFA concentrations at 3 h postfeeding when 60% DDGS diets were fed. There was no interaction detected (P > 0.05) for H(2)S or S(2-) concentrations in Exp. 2. Feeding 60% DDGS diets increased mean H(2)S by 71% when compared with feeding 25% DDGS diets. Similar to the response observed for H(2)S, feeding 60% DDGS diets increased mean S(2-) by 64% when compared with feeding 25% DDGS diets. Although these studies did not show beneficial effects of monensin supplementation on ruminal pH, VFA, or H(2)S concentrations, adverse rumen conditions, notably low ruminal pH, when high DDGS diets were fed may have precluded the effects of monensin from being realized.
进行了两项实验来评估莫能菌素和干酒糟及其可溶物（DDGS）对 8 头有瘘管的瘤胃代谢的影响。在实验 1 中，处理措施为（以干物质基础计）：1）日粮中不含莫能菌素，2）日粮中含 22mg 莫能菌素/kg，3）日粮中含 33mg 莫能菌素/kg，4）日粮中含 44mg 莫能菌素/kg。其余日粮为 10%玉米青贮料、60%DDGS、10%玉米和 20%矿物质补充料，以玉米为载体。日粮中添加莫能菌素对干物质采食量没有影响（P＞0.80）。增加日粮中的莫能菌素并没有影响（P＞0.05）瘤胃 VFA 浓度或乳酸浓度。增加日粮中莫能菌素浓度对瘤胃硫化氢（H2S）和液态硫化物（S2-）浓度或瘤胃 pH 没有影响（P＞0.15）。在实验 2 中，处理措施以 2×2 因子安排，包括（以干物质基础计）：1）日粮中不含莫能菌素+25%DDGS 添加，2）日粮中不含莫能菌素+60%DDGS 添加，3）日粮中含 44mg 莫能菌素/kg+25%DDGS 添加，4）日粮中含 44mg 莫能菌素/kg+60%DDGS 添加。其余日粮为 15%玉米青贮料、玉米和 20%矿物质补充料，以玉米为载体。当 60%DDGS 添加到日粮中时，与 25%DDGS 添加相比，干物质采食量降低（P＜0.01）。在添加 25%DDGS 的日粮中，与添加 60%DDGS 相比，0 小时时的乙酸浓度降低（P＜0.01）。总 VFA 浓度在 0 小时时也出现类似的反应（P＜0.01）。然而，在 3 和 6 小时时，无论是否添加莫能菌素，饲喂 60%DDGS 日粮的牛的丙酸浓度均增加（P≤0.05）。当饲喂 60%DDGS 日粮时，丙酸浓度的增加导致 3 小时时总 VFA 浓度增加（P=0.03）。在实验 2 中，未检测到（P＞0.05）H2S 或 S2-浓度的互作。与饲喂 25%DDGS 日粮相比，饲喂 60%DDGS 日粮使 H2S 平均增加 71%。与 H2S 的反应类似，与饲喂 25%DDGS 日粮相比，饲喂 60%DDGS 日粮使 S2-平均增加 64%。尽管这些研究没有表明莫能菌素添加对瘤胃 pH、VFA 或 H2S 浓度有有益影响，但高 DDGS 日粮可能导致瘤胃条件不利，尤其是瘤胃 pH 较低，从而使莫能菌素的作用无法实现。
