Department of Animal Sciences, The Ohio State University, Wooster 44691, USA.
J Anim Sci. 2011 Aug;89(8):2614-23. doi: 10.2527/jas.2010-3716. Epub 2011 Mar 31.
The objectives of this research were to determine the interaction of monensin and haylage supplementation for steers fed 60% dried distillers grains (DDGS) on 1) mineral status, performance, and carcass characteristics, and on 2) ruminal pH, H(2)S, and short-chain fatty acid concentrations. In Exp. 1, Angus-cross steers (n=168; BW=277 ± 67 kg) were blocked by BW and allotted in a 2 × 2 factorial arrangement of treatments to 24 pens. Dietary treatments were 1) 0 mg of monensin/kg of diet + 0% haylage, 2) 33 mg of monensin/kg of diet + 0% haylage, 3) 0 mg of monensin/kg of diet + 10% haylage, and 4) 33 mg of monensin/kg of diet + 10% haylage. The remainder of the diet was 60% DDGS, 10% corn silage, 15% supplement, and corn (either 5 or 15%) on a DM basis. When supplemented with 0 mg of monensin/kg of diet, added haylage increased ADG by 5.7%, whereas when supplemented with 33 mg of monensin/kg of diet, added haylage increased ADG by 13% (P < 0.01). No interactions of monensin and haylage were observed for DMI or G:F (P ≥ 0.36). Haylage inclusion increased (P < 0.01) DMI and decreased (P < 0.01) G:F. No interactions (P > 0.05) on plasma mineral concentrations were observed; however, over time, plasma Cu concentrations decreased (P < 0.01), whereas plasma ceruloplasmin and S concentrations increased (P < 0.01). There were no treatment effects (P ≥ 0.08) on carcass characteristics. Cattle fed the 60% DDGS diets benefitted from increased dietary forage, and the effects of monensin and forage were additive for ADG and final BW. In Exp. 2, ruminally fistulated steers (n=8; BW = 346 ± 34 kg) were used in a replicated 4 × 4 Latin square design and were randomly assigned to the diets used in Exp. 1. Haylage inclusion increased ruminal pH from 1.5 through 12 h postfeeding, and the effects of monensin supplementation were additive (P < 0.05). From 1.5 through 9 h postfeeding, steers fed 33 mg of monensin/kg of diet tended to have reduced (P ≤ 0.10) concentrations of H(2)S when compared with steers fed 0 mg of monensin/kg of diet. Acetate:propionate ratios at 6 h postfeeding were 0.94, 0.93, 1.29, and 1.35 for diets 1 to 4, respectively (P < 0.01); total lactate was decreased regardless of treatment (range: 0.94 to 1.42 µmol/mL). Sulfuric acid in DDGS, not ruminal short-chain fatty acids, may be responsible for the low rumen pH observed and may influence the maximum inclusion of DDGS in cattle diets. Monensin supplementation decreased H(2)S concentration and may decrease the risk of polioencephalomalacia for cattle fed high-DDGS diets.
本研究的目的是确定莫能菌素与干草青贮料联合添加对饲喂 60%干酒糟及其可溶物（DDGS）日粮的肉牛的影响，主要涉及以下方面：1）矿物质状况、生产性能和胴体特性；2）瘤胃 pH 值、H₂S 和短链脂肪酸浓度。试验 1 中，安格斯杂交公牛（n=168；BW=277±67 kg）根据 BW 进行分组，然后采用 2×2 因子设计安排到 24 个栏中。日粮处理为：1）0 mg 莫能菌素/kg 日粮+0%干草青贮料，2）33 mg 莫能菌素/kg 日粮+0%干草青贮料，3）0 mg 莫能菌素/kg 日粮+10%干草青贮料，4）33 mg 莫能菌素/kg 日粮+10%干草青贮料。其余日粮由 60% DDGS、10%玉米青贮、15%补充料和玉米（以 DM 为基础，分别为 5%或 15%）组成。当添加 0 mg 莫能菌素/kg 日粮时，添加干草青贮料可提高 ADG 5.7%，而添加 33 mg 莫能菌素/kg 日粮时，添加干草青贮料可提高 ADG 13%（P<0.01）。添加或不添加莫能菌素，干草青贮料对 DMI 或 G:F 没有互作效应（P≥0.36）。添加干草青贮料可提高 DMI（P<0.01），降低 G:F（P<0.01）。添加或不添加莫能菌素对血浆矿物质浓度没有影响（P>0.05）；然而，随着时间的推移，血浆铜浓度降低（P<0.01），而血浆铜蓝蛋白和 S 浓度增加（P<0.01）。添加或不添加莫能菌素对胴体特性没有影响（P≥0.08）。饲喂 60% DDGS 日粮的牛受益于增加的日粮粗饲料，莫能菌素和粗饲料对 ADG 和最终 BW 的影响具有累加效应。试验 2 中，使用装有瘤胃瘘管的安格斯杂交公牛（n=8；BW=346±34 kg）进行重复 4×4 拉丁方设计，并随机分配到试验 1 中使用的日粮。添加干草青贮料可使瘤胃 pH 值从 1.5 小时到 12 小时后增加，并且莫能菌素添加的效果具有累加效应（P<0.05）。从 1.5 小时到 9 小时后，与饲喂 0 mg 莫能菌素/kg 日粮的公牛相比，饲喂 33 mg 莫能菌素/kg 日粮的公牛的 H₂S 浓度降低（P≤0.10）。6 小时后，日粮 1 到 4 的乙酸：丙酸比分别为 0.94、0.93、1.29 和 1.35（P<0.01）；无论处理如何，总乳酸盐都减少（范围：0.94 到 1.42 μmol/mL）。DDGS 中的硫酸可能是造成观察到的低瘤胃 pH 值的原因，也可能影响 DDGS 在牛日粮中的最大添加量。莫能菌素添加可降低 H₂S 浓度，可能降低饲喂高 DDGS 日粮牛的脑灰质软化症的风险。
