USDA-ARS U. S. Meat Animal Research Center, Clay Center, NE 68933, USA.
J Anim Sci. 2013 Sep;91(9):4277-89. doi: 10.2527/jas.2013-6341. Epub 2013 Jul 26.
One experiment was conducted to evaluate the influence of glycerin (GLY) on animal performance and health when used as a partial replacement for roughage in receiving diets. The second experiment was conducted using ruminally and duodenally cannulated steers in a 4 × 4 Latin square to determine the site of nutrient digestion and ruminal fermentation characteristics when GLY replaced roughage at 0%, 2.5%, 5%, and 10% of diet DM. In Exp. 1, steers (initial BW = 245 ± 2.3 kg) were fed treatment diets over a 42-d period that consisted of a control diet based on steam-flaked corn with GLY inclusion in replacement of dietary roughage at 0%, 5%, and 10% of diet DM. A linear reduction in DMI was observed as GLY increased (P = 0.01). Glycerin incorporation tended to improve G:F in a linear manner (P = 0.07); efficiency was improved 5.4% and 4.7% at 5% and 10% GLY. The number of animals receiving treatment for bovine respiratory disease did not differ among treatments. Furthermore, there were no differences among treatments for mortality or the frequency of steers that were seropositive for serum antibody titers to infectious bovine rhinotracheitis on d 28. In Exp. 2, apparent OM and apparent and true starch digestibility increased linearly (P < 0.05) as GLY concentration increased, whereas true OM digestibility responded in a quadratic (P < 0.01) manner. Bacterial OM and bacterial starch flow responded quadratically (P ≤ 0.02), and flow increased from 0% to 5% GLY inclusion and decreased thereafter. Feed OM flow responded quadratically (P ≤ 0.05), where it decreased from 0% to 2.5% GLY and increased from 2.5% to 10% GLY inclusion. Feed starch (P = 0.02) and total starch (P = 0.02) flow from the duodenum decreased linearly as the concentration of GLY increased in the diet. Bacterial N flow to the duodenum responded quadratically (P < 0.01); it increased with increasing GLY in the diet up to 5% and then decreased from 5% to 10%. The acetate to propionate (A:P) ratio in the ruminal fluid decreased (P < 0.05) as the concentration of GLY in the diet increased, which could have implications on improved G:F. The decrease in the A:P ratio as GLY increased in the diet, coupled with the linear decrease in DMI and improvement in G:F with GLY addition up to 5% of DM in place of roughage, implies that GLY is a viable dietary ingredient in growing and receiving diets.
一项实验评估了甘油（GLY）作为替代部分粗饲料在接收日粮中的应用对动物生产性能和健康的影响。第二项实验使用瘤胃和十二指肠插管的肉牛进行 4×4 拉丁方设计，以确定当 GLY 替代日粮中 0%、2.5%、5%和 10%的粗饲料时，养分消化部位和瘤胃发酵特性。在实验 1 中，牛（初始 BW = 245 ± 2.3 kg）在 42 天的时间内饲喂处理日粮，这些日粮基于蒸汽压扁的玉米，含有 GLY，以替代日粮中的粗饲料，替代比例为 0%、5%和 10%的日粮 DM。随着 GLY 的增加，DMI 呈线性下降（P = 0.01）。GLY 的添加线性改善了 G:F（P = 0.07）；添加 5%和 10%GLY 时，效率分别提高了 5.4%和 4.7%。接受牛呼吸道疾病治疗的动物数量在处理之间没有差异。此外，在处理之间，死亡率或在第 28 天对传染性牛鼻气管炎血清抗体滴度呈血清阳性的牛的频率没有差异。在实验 2 中，随着 GLY 浓度的增加，OM 的表观消化率和表观和真淀粉消化率呈线性增加（P <0.05），而真 OM 消化率呈二次（P <0.01）方式响应。细菌 OM 和细菌淀粉流量呈二次（P ≤ 0.02）响应，从 0%GLY 添加到 5%GLY 增加，此后减少。饲料 OM 流量呈二次（P ≤ 0.05）响应，从 0%GLY 到 2.5%GLY 减少，从 2.5%GLY 到 10%GLY 添加增加。随着日粮中 GLY 浓度的增加，饲料淀粉（P = 0.02）和总淀粉（P = 0.02）从十二指肠流出呈线性下降。十二指肠中细菌 N 的流出量呈二次（P <0.01）响应；随着日粮中 GLY 的增加，它在 5%之前增加，然后从 5%到 10%减少。随着日粮中 GLY 浓度的增加，瘤胃液中的乙酸/丙酸（A:P）比降低（P <0.05），这可能对改善 G:F 有影响。随着日粮中 GLY 的增加，A:P 比降低，同时 DMI 线性降低，添加 GLY 至 5%DM 代替粗饲料可提高 G:F，这意味着 GLY 是生长和接收日粮中一种可行的饲料成分。
