The objective of this study was to evaluate effects of increasing the inclusion of dry-rolled hybrid rye (HR) as a replacement for dry-rolled barley grain (DRB) on feed intake, ruminal fermentation, and the site and extent of nutrient digestion for finishing cattle. Eight ruminally and duodenally cannulated Hereford-cross heifers were used in a replicated 4×4 Latin square design with 21-d periods including 15 d of dietary adaptation and 6 d of data and sample collection. Dietary treatments included a control diet with 10.00% grass hay, 85.21% DRB, 4.51% of a vitamin and mineral supplement, and 0.28% of urea on a dry matter (DM) basis. Hybrid rye grain replaced 33, 67, or 100% of the DRB. Feed ingredients, feed refusals, ruminal pH, ruminal fluid, duodenal digesta, and fecal samples were collected from d 18 to 21 in each period. Data were analyzed using the Proc Glimmix procedure of SAS 9.4 (SAS Inst. Inc., Cary, NC) to evaluate the linear, quadratic, and cubic effects of increasing HR inclusion. Increasing HR inclusion as a substitute for DRB linearly decreased (P < 0.01) DM intake, linearly decreased mean pH (P < 0.01), and increased the duration (P < 0.01) and area (P = 0.02) that pH was <5.5. There were no effects of HR inclusion on total short chain fatty acid and lactic acid concentrations. Likewise, the molar proportions of acetate and butyrate were not affected by HR inclusion. Propionate was cubically affected by HR inclusion (P = 0.02). Ruminal ash-free neutral detergent fiber (aNDFom) digestibility linearly increased (P = 0.03) with increasing HR, but there was no effect on ruminal starch digestibility averaging 71.1% (SEM = 3.611). Increasing HR inclusion linearly increased intestinal DM digestibility (% of flow to the duodenum; P = 0.03), tended to linearly increase intestinal digestibility of organic matter (P = 0.08), and tended to quadratically affect intestinal digestibility of aNDFom (P = 0.07). Increasing hybrid rye linearly increased apparent total tract DM, organic matter, crude protein, aNDFom, and starch digestibility (P ≤ 0.05). In addition, increasing HR inclusion linearly increased GE digestibility (P < 0.01) and DE concentration (P < 0.01). Increasing the inclusion rate of HR grain as a substitute for DRB in finishing diets may decrease DMI and increase risk for low ruminal pH, which may be influenced by greater digestible energy concentration arising from greater DM, OM, aNDFom, and starch digestibility.

中文翻译：

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饲喂杂交黑麦谷物替代大麦谷物对育肥小母牛干物质摄入、瘤胃发酵以及营养物质消化部位和程度的影响


本研究的目的是评估增加干轧杂交黑麦 (HR) 的添加量作为干轧大麦 (DRB) 的替代品对采食量、瘤胃发酵以及养分消化部位和程度的影响。整理牛。八头瘤胃和十二指肠插管的赫里福德杂交小母牛用于重复的 4×4 拉丁方设计，21 天的周期包括 15 天的饮食适应和 6 天的数据和样本收集。饮食治疗包括对照饮食，其中含有 10.00% 干草、85.21% DRB、4.51% 维生素和矿物质补充剂以及基于干物质 (DM) 的 0.28% 尿素。杂交黑麦谷物取代了 33%、67% 或 100% 的 DRB。每个时期的第 18 至 21 天收集饲料成分、拒食率、瘤胃 pH 值、瘤胃液、十二指肠食糜和粪便样本。使用 SAS 9.4 (SAS Inst. Inc., Cary, NC) 的 Proc Glimmix 程序对数据进行分析，以评估增加 HR 包含的线性、二次和三次效应。增加 HR 含量作为 DRB 的替代品可线性降低 (P < 0.01) DM 摄入量，线性降低平均 pH (P < 0.01)，并增加 pH 值的持续时间 (P < 0.01) 和面积 (P = 0.02)。 <5.5。 HR 含量对总短链脂肪酸和乳酸浓度没有影响。同样，乙酸盐和丁酸盐的摩尔比例也不受 HR 包含物的影响。 HR 含量对丙酸盐的影响呈三次方变化 (P = 0.02)。瘤胃无灰中性洗涤纤维 (aNDFom) 消化率随着 HR 的增加而线性增加 (P = 0.03)，但对瘤胃淀粉消化率没有影响，平均为 71.1% (SEM = 3.611)。增加 HR 含量可线性增加肠道 DM 消化率（流向十二指肠的百分比；P = 0。03），倾向于线性增加有机物的肠道消化率（P = 0.08），并且倾向于以二次方方式影响aNDFom的肠道消化率（P = 0.07）。增加杂交黑麦可线性增加表观总干物质、有机质、粗蛋白、aNDFom 和淀粉消化率（P ≤ 0.05）。此外，增加 HR 含量会线性增加 GE 消化率 (P < 0.01) 和 DE 浓度 (P < 0.01)。在育肥日粮中增加HR谷物作为DRB的替代品的含量可能会降低DMI并增加低瘤胃pH值的风险，这可能受到较高的DM、OM、aNDFom和淀粉消化率产生的较高的可消化能量浓度的影响。