Effects of ruminal or duodenal supply of fish oil on milk fat secretion and profiles of trans-fatty acids and conjugated linoleic acid isomers in dairy cows fed maize silage
Effects of ruminal or duodenal supply of fish oil on milk fat secretion and profiles of trans-fatty acids and conjugated linoleic acid isomers in dairy cows fed maize silage
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DOI：
10.1016/j.anifeedsci.2004.12.016
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发表时间：
2005-04-04
影响因子：
3.2
通讯作者：
Chilliard, Y
中科院分区：
文献类型：
--
作者：
Loor, JJ;Doreau, M;Chilliard, Y
使用六头在瘤胃和十二指肠插管的泌乳荷斯坦奶牛，评估了由于瘤胃或十二指肠供应鱼油（FO；EPA = 总脂肪酸的 22%，DHA = 7%）而产生的乳脂分泌以及乳脂中共轭亚油酸 (CLA) 和反式 18:1 异构体的分布。采用重复的 3 x 3 拉丁方设计，将奶牛饲喂基于玉米青贮饲料（66% 干物质）的对照日粮，或将对照日粮加 300 mL FO/天放入瘤胃 (FO-R) 或十二指肠 (FO-D) 中，持续 4 周。对照组的干物质摄入量较高（19.8 kg/d），FO-D 的干物质摄入量中等（18.0 kg/d），FO-R 的干物质摄入量较低（16.2 kg/d）。产奶量（22.7 kg/d）、乳糖（1.09 kg/d）或粗蛋白（0.70 kg/d）不受处理影响。与对照相比，FO-R 处理后的粗蛋白、真蛋白和酪蛋白含量较低。尽管与对照组相比，颈静脉浓度相似，但 FO-R 或 FO-D 的 β-OH-丁酸盐颈静脉-乳腺静脉差异降低了 54%。与 FO-D（32 g/kg，737 g/d）或对照（35 g/kg，783 g/d）相比，FO-R（25 g/kg，567 g/d）的乳脂含量和产量最低。与对照或 FO-D 相比，FO-R 导致乳脂中反式 5-、反式 6+7+8-、反式 9-、反式 10-、反式 11-、反式 12- 和反式 13+14-18:1 的百分比更高（分别为 0.05、0.44、0.48、1.8、9.2、0.70 和 0.82%） （0.02、0.22、0.19、0.27、1.1、0.35 和 0.40%）。尽管 FO-R 的 18:0 和 cis9-18:1 百分比明显较低，但与对照或 FO-D 相比，cis11-、cis13- 和 cis15-18:1 的百分比更高。 Cis9,trans11-CLA（总 CLA 的 87-95%）对 FO-R 的反应平均为 3.2%，而对照或 FO-D 为 0.51%。未检测到反式10、顺式12-18:2。在非缀合 18:2 异构体中，当 FO-R 与对照或 FO-D 相比时，cis9,cis12-18:2 较低，但 cis9,trans13-、trans9,cis12- 和 trans11,cis15-18:2 较高。对于大多数反式 18:1 异构体和顺式 9,反式 18:2 异构体，通过 GLC 与 HPLC 获得的数据之间存在高度相关性 (r = 0.94-0.99)，表明单独使用 GLC 和我们的色谱条件即可充分分离异构体。牛奶 20:5n-3 (EPA) 和 22:6n-3 (DHA) 在对照中分别为 0.08 和 0.04%，在 FO-R 中增加到 0.36 和 0.17%，在 FO-D 中分别增加到 1.47 和 0.47%。数据表明，瘤胃供应FO导致EPA和DHA氢化，乳脂中各种反式18:1、顺式18:1、非结合18:2和顺式9、反式11-18:2的百分比增加。反式 18:1 的增加以及顺式 9-18:1 内源合成的 18:0 可用性的降低可能在减少饲喂鱼油的奶牛的乳脂合成中发挥关键作用。 (C) 2005 Elsevier B.V. 保留所有权利。
Milk fat secretion and profiles of conjugated linoleic acids (CLA) and trans-18:1 isomers in milk fat due to a ruminal or duodenal supply of fish oil (FO; EPA = 22% of total fatty acids, DHA = 7%) were evaluated using six lactating Holstein cows with cannulas in their rumen and duodenum. Cows were fed a control diet based on corn silage (66% of DM), or the control plus 300 mL FO/d into the rumen (FO-R) or duodenum (FO-D) for 4 weeks in a replicated 3 x 3 Latin square design. Dry matter intake was higher with the control (19.8 kg/d), intermediate with FO-D (18.0 kg/d), and lower with FO-R (16.2 kg/d). Yield of milk (22.7 kg/d), lactose (1.09 kg/d), or crude protein (0.70 kg/d) was not affected by treatments. Content of crude protein, true protein, and casein was lower in response to FO-R compared with the control. Despite similar jugular concentration compared with the control, jugular-mammary venous difference for beta-OH-butyrate was 54% lower with FO-R or FO-D. Milk fat content and yield were lowest with FO-R (25 g/kg, 567 g/d) compared with FO-D (32 g/kg, 737 g/d) or the control (35 g/kg, 783 g/d). Percentage of trans5-, trans6+7+8-, trans9-, trans 10-, trans11-,transl2-, and trans13+14-18:1 in milk fat was greater due to FO-R (0.05, 0.44, 0.48, 1.8, 9.2, 0.70, and 0.82%, respectively) compared with the control or FO-D (0.02, 0.22, 0.19, 0.27, 1.1, 0.35, and 0.40%). Although 18:0 and cis9-18:1 percentage was markedly lower in response to FO-R, percentage of cis11-, cis13-, and cis15-18:1 was greater compared with the control or FO-D. Cis9,trans11-CLA (87-95% of total CLA) averaged 3.2% in response to FO-R compared with 0.51% for control or FO-D. Trans10,cis12-18:2 was not detected. Among non-conjugated 18:2 isomers, cis9,cis12-18:2 was lower but cis9,trans13-, trans9,cis12-, and trans11,cis15-18:2 greater when FO-R was compared with the control or FO-D. There was high correlation (r = 0.94-0.99) among data obtained by GLC versus HPLC for most trans-18:1 isomers and cis9,trans11-18:2, suggesting GLC alone with our chromatographic conditions provided adequate separation of isomers. Milk 20:5n-3 (EPA) and 22:6n-3 (DHA) were 0.08 and 0.04% with the control, increased to 0.36 and 0.17% with FO-R, and were 1.47 and 0.47% with FO-D. Data indicate, ruminal supply of FO led to hydrogenation of EPA and DHA and enhanced percentage of various trans-18: 1, cis-18:1, non-conjugated 18:2, and cis9,trans11-18:2 in milk fat. Combined increases in trans-18:1 along with reduced availability of 18:0 for endogenous synthesis of cis9-18:1 may play a key role in reduced milk fat synthesis in cows fed fish oil. (C) 2005 Elsevier B.V. All rights reserved.