Feeding high proportions of barley grain stimulates an inflammatory response in dairy cows
Feeding high proportions of barley grain stimulates an inflammatory response in dairy cows
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DOI：
10.3168/jds.2007-0256
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发表时间：
2008-02-01
影响因子：
3.5
通讯作者：
Ametaj, B. N.
中科院分区：
文献类型：
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作者：
Emmanuel, D. G. V.;Dunn, S. M.;Ametaj, B. N.
本研究的目的是评估饲喂比例增加的大麦对泌乳奶牛急性期反应的影响。采用4 × 4拉丁方试验设计，将8头经插管分娩的荷斯坦奶牛（产奶60 ~ 140 d）分配至4种日粮组。实验期为21 d，其中适应期11 d，测量期10 d。奶牛饲喂以下饮食：1）饮食中无大麦谷物，2）15%大麦谷物，3）30%大麦谷物，和4）45%大麦谷物，以及85%、70%、55%和40% [干物质（DM）基础]的大麦和苜蓿青贮饲料和苜蓿干草。所有奶牛均补充了15%的精料混合物。在测定期的第1、3、5、7、10 d采集血液和瘤胃液样品，测定瘤胃液pH值和内毒素含量。血清淀粉样蛋白A，脂多糖结合蛋白，结合珠蛋白，血浆中的C-反应蛋白的浓度通过ELISA测定。饲喂高比例的大麦（0、15、30和45%干物质）与较低的采食量相关（分别为32.6、32.9、27.34和25.18 kg/d +/- 1.30），降低瘤胃pH（分别为6.8、6.7、6.7和6.5 +/- 0.03），DM摄入量较高（分别为13.33、15.28、14.68和16.04 ± 0.63 kg/d）和产奶量（分别为27.2、28.2、29.0和31.0 ± 1.2 kg/d）。与不饲喂谷物或饲喂15%大麦谷物的奶牛（分别为654和790 +/-393 ng/mL）相比，饲喂30%和45%大麦谷物的奶牛（分别为5，021和8，870 +/- 393 ng/mL）瘤胃内毒素增加。给予较高比例（30%和45%）谷物的奶牛血清淀粉样蛋白A、脂多糖结合蛋白和C反应蛋白的血浆浓度增加。血浆触珠蛋白不受处理的影响。总之，饲喂奶牛高比例（30和45% DM基础）的大麦颗粒与较低的采食量和瘤胃pH值，增加瘤胃液中的内毒素，刺激炎症反应。
The objective of this study was to evaluate effects of feeding increasing proportions of barley grain on acute phase response in lactating dairy cows. Eight cannulated primiparous (60 to 140 d in milk) Holstein dairy cows were assigned to 4 diets in a 4 x 4 Latin square experimental design. The experimental period lasted for 21 d, with 11 d of adaptation and 10 d of measurements. Cows were fed the following diets: 1) no barley grain in the diet, 2) 15% barley grain, 3) 30% barley grain, and 4) 45% barley grain, as well as barley and alfalfa silage and alfalfa hay at 85, 70, 55, and 40% [dry matter (DM) basis]. All cows were supplemented with a 15% concentrate mix. Blood and rumen fluid samples were collected on d 1, 3, 5, 7, and 10 of the measurement period, and pH and endotoxin content were measured in rumen samples. Concentrations of serum amyloid A, lipopolysaccharide-binding protein, haptoglobin, and C-reactive protein in plasma were measured by ELISA. Feeding high proportions of barley grain at 0, 15, 30, and 45% of DM was associated with lower feed intake (32.6, 32.9, 27.34, and 25.18 kg/d +/- 1.30, respectively), lower ruminal pH (6.8, 6.7, 6.7, and 6.5 +/- 0.03, respectively), and higher DM intake (13.33, 15.28, 14.68, and 16.04 +/- 0.63 kg/d, respectively) and milk production (27.2, 28.2, 29.0, and 31.0 +/- 1.2 kg/d, respectively). Ruminal endotoxin increased in cows receiving 30 and 45% barley grain (5,021, and 8,870 +/- 393 ng/mL, respectively) compared with those fed no grain or 15% barley grain (654 and 790 +/- 393 ng/mL, respectively). Plasma concentrations of serum amyloid A, lipopolysaccharide-binding protein, and C-reactive protein increased in cows given higher (30 and 45%) proportions of grain. Plasma haptoglobin was not affected by treatments. In conclusion, feeding dairy cows high proportions (30 and 45% DM basis) of barley grain was associated with lower feed intake and rumen pH, increased endotoxin in the rumen fluid, and stimulation of an inflammatory response.