Emanuele S M, Staples C R
Department of Dairy Science, University of Florida, Gainesville 32611.
J Dairy Sci. 1994 Aug;77(8):2382-92. doi: 10.3168/jds.S0022-0302(94)77181-2.
Objectives for this study were to determine the effect of energy supplementation on mineral release in and outflow from the rumen, independent of pH. Nonlactating Holstein cattle with ruminal cannulas were limit-fed chopped alfalfa hay with or without energy supplement. Treatments were 1) control, alfalfa plus ruminal infusion of 3 L/d of distilled water; 2) acid, alfalfa plus infusion of 3 L/d of 1N HCl; 3) energy supplement, alfalfa and ground corn plus infusion of 3 L/d of distilled water; and 4) buffered energy supplement, alfalfa, and ground corn plus infusion of 3 L/d of distilled water containing 90 g of NaHCO3. Macromineral intake was standardized across treatments by adjustment of infusion solutions with inorganic mineral sources. Dry matter consumed was 5 kg/d on treatments 1 and 2 and 8.4 kg/d on treatments 3 and 4. Mean ruminal pH was 6.8, 6.1, 5.6, and 6.2 for treatments 1 through 4, respectively. Ruminal pH was more significant than energy supplementation in dispersion of Ca, Mg, and P in ruminal digesta. Only 1, 17, and 27% of dietary K, Mg, and P flowed with solids from the rumen, but 52% of Ca and 41% of Cu remained with the solid phase.
本研究的目的是确定能量补充对瘤胃内矿物质释放及流出的影响，且不受pH值影响。给装有瘤胃瘘管的非泌乳荷斯坦奶牛限量饲喂切碎的苜蓿干草，添加或不添加能量补充剂。处理方式如下：1）对照组，苜蓿加每天瘤胃灌注3升蒸馏水；2）酸处理组，苜蓿加每天灌注3升1N盐酸；3）能量补充剂组，苜蓿和玉米粉加每天灌注3升蒸馏水；4）缓冲能量补充剂组，苜蓿、玉米粉加每天灌注3升含90克碳酸氢钠的蒸馏水。通过用无机矿物质源调整灌注溶液，使各处理间的常量矿物质摄入量标准化。处理1和2的干物质摄入量为每天5千克，处理3和4为每天8.4千克。处理1至4的瘤胃平均pH值分别为6.8、6.1、5.6和6.2。在瘤胃消化物中钙、镁和磷的分散方面，瘤胃pH值比能量补充更显著。日粮中只有1%的钾、17%的镁和27%的磷随固体物质从瘤胃流出，但52%的钙和41%的铜仍留在固相。
