Graziella Joyce O, Loh Huey Yi, Muco Cindy, Heldt Jeff S, Spears Jerry W, Engle Terry E
Department of Animal Science and Food Engineering, University of São Paulo, Pirassununga, 13635-900, Brazil.
Department of Animal Science, Colorado State University, 350 West Pitkin Street, Fort Collins, CO 80523, USA.
Biol Trace Elem Res. 2025 Jun 23. doi: 10.1007/s12011-025-04720-z.
Sixteen Angus crossbred steers were used to determine the impact of trace mineral (TM) source, diet type, and monensin and tylosin supplementation on rumen fermentation characteristics. Experiment 1: Steers were adapted to a finishing diet before being assigned dietary treatments. A 2 × 2 factorial arrangement of treatments was utilized with factors: (1) TM source (sulfate; STM or hydroxy; HTM) and (2) with or without monensin and tylosin (MT). Following the 28-day feeding period, rumen samples were collected at 0, 2, and 4 h post-feeding. Experiment 2: Steers were adapted to a lactating dairy cow diet and assigned dietary treatments for 28 days. A 2 × 2 factorial arrangement of treatments was utilized. Factors included (1) TM source (STM or HTM) and (2) with or without monensin (M). On day 29, rumen samples were collected at 0, 2, and 4 h post-feeding. Rumen fluid samples from both experiments were analyzed for short chain fatty acids (SCFA), pH, and ammonia concentrations. Experiment 1: Molar proportions of acetate were lesser (P < 0.04) and propionate greater (P < 0.01) in steers receiving HTM compared to steers receiving STM. Experiment 2: Total SCFA production was greater (P < 0.01) in steers supplemented with HTM compared to STM. Supplementation of M reduced the molar proportion (P < 0.01) of acetate and increased (P < 0.05) molar proportions of propionate and butyrate. These data indicate that TM source and M may modulate rumen fermentation characteristics but their impacts on rumen fermentation may be diet dependent.
选用16头安格斯杂交阉牛来确定微量矿物质（TM）来源、日粮类型以及莫能菌素和泰乐菌素添加对瘤胃发酵特性的影响。实验1：阉牛在接受日粮处理前先适应育肥日粮。采用2×2析因设计处理，因素包括：（1）TM来源（硫酸盐；STM或羟基；HTM）和（2）添加或不添加莫能菌素和泰乐菌素（MT）。在28天的饲喂期后，于采食后0、2和4小时采集瘤胃样本。实验2：阉牛先适应泌乳奶牛日粮，然后进行28天的日粮处理。采用2×2析因设计处理。因素包括（1）TM来源（STM或HTM）和（2）添加或不添加莫能菌素（M）。在第29天，于采食后0、2和4小时采集瘤胃样本。对两个实验的瘤胃液样本进行短链脂肪酸（SCFA）、pH值和氨浓度分析。实验1：与接受STM的阉牛相比，接受HTM的阉牛乙酸的摩尔比例较低（P＜0.04），丙酸的摩尔比例较高（P＜0.01）。实验2：与接受STM的阉牛相比，添加HTM的阉牛总SCFA产量更高（P＜0.01）。添加M降低了乙酸的摩尔比例（P＜0.01），增加了丙酸和丁酸的摩尔比例（P＜0.05）。这些数据表明，TM来源和M可能调节瘤胃发酵特性，但它们对瘤胃发酵的影响可能取决于日粮。
