The objective of this study was to determine whether increasing propionate alters dry matter intake (DMI), glucose clearance rate, blood metabolites, insulin concentrations, and hepatic gene expression in steers fed a finishing diet. Holstein steers (n = 15; BW = 243 ± 3.6 kg) were individually fed a finishing diet ad libitum. Steers were allocated by body weight (BW) to receive: no Ca propionate (Control), 100 g/d Ca propionate (Low), or 300 g/d Ca propionate (High) in the diet. Orts were collected and weighed daily to determine DMI. Blood samples were collected on days 0, 7, and 21, and BW recorded on days 0, 14, and 28. An intravenous glucose tolerance test (IVGTT) was conducted on days 14 and 28 of the trial. Liver biopsies were collected on day 33 for gene expression analysis. Blood samples were analyzed for whole blood glucose and lactate, plasma non-esterified fatty acids (NEFAs), and insulin concentrations. Data were analyzed using a mixed model with treatment, day and their interaction included, with day and minute as a repeated measure. The control treatment had greater (P < 0.01) DMI than low and high steers. Body weight was increased in control steers on days 14 and 28 compared with the steers receiving the High treatment (P = 0.03 for the interaction). Blood glucose concentrations tended (P = 0.09) to be higher on day 21 than days 0 and 7 but was not affected by treatment (P = 0.58). Plasma NEFA concentrations were lower (P = 0.05) for control steers than other treatments, and greater (P = 0.002) on day 0 than days 7 and 21. Blood lactate concentrations were greater (P = 0.05) on day 7, than days 0 and 21, but not affected by treatment (P = 0.13). High steers had greater plasma insulin concentrations in response to the IVGTT than steers on the other treatments (P = 0.001). There was no treatment (P ≥ 0.16) or day effect (P ≥ 0.36) on glucose peak, plateau, or clearance rate. High steers had greater expression of solute carrier family 16 member 1 (SLC16A1; P = 0.05) and tended to have greater hepatic expression of solute carrier family 2 member 2 (SLC2A2; P = 0.07). These data indicate that increased propionate may decrease DMI and insulin sensitivity.

中文翻译：

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日粮中增加丙酸钙对肉牛干物质摄入量和葡萄糖代谢的影响

本研究的目的是确定增加丙酸盐是否会改变饲喂精加工日粮的公牛的干物质摄入量 (DMI)、葡萄糖清除率、血液代谢物、胰岛素浓度和肝脏基因表达。荷斯坦肉牛 (n = 15; BW = 243 ± 3.6 kg) 被单独饲喂自由采食。阉牛按体重 (BW) 分配以接受：日粮中不含丙酸钙（对照）、100 g/d 丙酸钙（低）或 300 g/d 丙酸钙（高）。每天收集 Orts 并称重以确定 DMI。在第 0、7 和 21 天采集血样，并在第 0、14 和 28 天记录体重。在试验的第 14 天和第 28 天进行了静脉葡萄糖耐量试验 (IVGTT)。在第 33 天收集肝活检用于基因表达分析。分析血液样本的全血葡萄糖和乳酸，血浆非酯化脂肪酸 (NEFA) 和胰岛素浓度。使用混合模型分析数据，包括治疗、天及其相互作用，以天和分钟作为重复测量。对照处理的 DMI 比低和高的转向更大 (P < 0.01)。与接受高处理的公牛相比，对照公牛在第 14 天和第 28 天的体重增加（相互作用 P = 0.03）。第 21 天的血糖浓度 (P = 0.09) 高于第 0 天和第 7 天，但不受治疗影响 (P = 0.58)。对照阉牛的血浆 NEFA 浓度低于其他处理（P = 0.05），并且在第 0 天比第 7 天和第 21 天更高（P = 0.002）。第 7 天的血乳酸浓度高于第 0 天（P = 0.05）和 21，但不受治疗影响 (P = 0.13)。对 IVGTT 的反应，高牛的血浆胰岛素浓度高于其他治疗的牛 (P = 0.001)。对葡萄糖峰值、平台期或清除率没有治疗 (P ≥ 0.16) 或日效应 (P ≥ 0.36)。高阉牛的溶质载体家族 16 成员 1 (SLC16A1; P = 0.05) 的表达更高，溶质载体家族 2 成员 2 (SLC2A2; P = 0.07) 的肝脏表达往往更高。这些数据表明增加丙酸盐可能会降低 DMI 和胰岛素敏感性。05) 并且倾向于在肝脏表达更多的溶质载体家族 2 成员 2 (SLC2A2; P = 0.07)。这些数据表明增加丙酸盐可能会降低 DMI 和胰岛素敏感性。05) 并且倾向于在肝脏表达更多的溶质载体家族 2 成员 2 (SLC2A2; P = 0.07)。这些数据表明增加丙酸盐可能会降低 DMI 和胰岛素敏感性。