Donovan G A, Risco C A, Temple G M DeChant, Tran T Q, van Horn H H
Department of Large Animal Clinical Sciences, and University of Florida, Gainesville 32610, USA.
J Dairy Sci. 2004 Jan;87(1):73-84. doi: 10.3168/jds.s0022-0302(04)73144-6.
Pre- and postpartum diets varying in energy and fiber were studied for effects on subclinical laminitis in Holstein cows. Also, ruminal acidosis was examined relative to sole hemorrhages and ulcers. Cows (n = 98) were assigned to a 2 x 2 factorial arrangement of treatments in a randomized complete block. Diets high in net energy of lactation (NE(L)) and low fiber were classified as high NE(L), whereas low NE(L) and higher fiber were defined as low NE(L). Two diets were fed for 3 wk before calving and 2 others fed for 3 wk postpartum resulting in 4 treatment combinations: high NE(L), low NE(L); high NE(L), high NE(L); low NE(L), low NE(L); and low NE(L), high NE(L). Levels of NE(L) (Mcal/kg DM), percentage of acid detergent fiber, and percentage of neutral detergent fiber for low NE(L) vs. high NE(L) prepartum diets, were 1.51, 30.2, 47.2 vs. 1.65, 23.4, 39.8, respectively, and 1.70, 22.4, 36.8 vs. 1.77, 17.5, 31.4 for low NE(L) vs. high NE(L) lactating diets, respectively. A single diet was fed after 21 d in milk (DIM). Measures of hoof discoloration, hemorrhage, and/or ulcer formation were done at about 45 d before calving, and near 28 and 70 DIM. Rumenocentesis was performed 14 d before calving and at 8, 22, and 70 DIM. Hoof scores among treatments were similar at 28 DIM. The low NE(L), high NE(L) group had less desirable hoof scores than high NE(L), high NE(L), or low NE(L), low NE(L) groups from 55 to 75 DIM. Rumen pH did not differ by treatment before calving. The lowest postpartum rumen pH was significantly lower and rates of ruminal acidosis (pH < or = 5.8) at 8 and 22 DIM were higher for groups fed high NE(L) after calving. No direct relationship between low postpartum rumen pH and hoof scores on individual cows was found. Low NE(L) before calving and high NE(L) right after calving may increase risk of subclinical laminitis if not carefully managed.
研究了能量和纤维含量不同的产前和产后日粮对荷斯坦奶牛亚临床蹄叶炎的影响。此外，还研究了瘤胃酸中毒与蹄底出血和溃疡的关系。将98头奶牛随机完全区组设计，按2×2析因排列进行处理。泌乳净能量（NE(L)）高且纤维含量低的日粮归类为高NE(L)，而NE(L)低且纤维含量高的日粮定义为低NE(L)。两种日粮在产犊前饲喂3周，另外两种日粮在产后饲喂3周，从而产生4种处理组合：高NE(L)，低NE(L)；高NE(L)，高NE(L)；低NE(L)，低NE(L)；以及低NE(L)，高NE(L)。产前低NE(L)日粮与高NE(L)日粮的NE(L)水平（Mcal/kg DM）、酸性洗涤纤维百分比和中性洗涤纤维百分比分别为1.51、30.2、47.2和1.65、23.4、39.8，产后低NE(L)日粮与高NE(L)日粮分别为1.70、22.4、36.8和1.77、17.5、31.4。产奶21天后（DIM）饲喂单一日粮。在产犊前约45天、产犊后28天和70天左右对蹄部变色、出血和/或溃疡形成情况进行测量。在产犊前14天以及8、22和70 DIM进行瘤胃穿刺。各处理组在28 DIM时的蹄部评分相似。从55至75 DIM，低NE(L)、高NE(L)组的蹄部评分不如高NE(L)、高NE(L)组或低NE(L)、低NE(L)组理想。产犊前各处理组的瘤胃pH无差异。产后瘤胃pH最低值显著较低，产后饲喂高NE(L)的组在8和22 DIM时的瘤胃酸中毒发生率（pH≤5.8）较高。未发现个体奶牛产后瘤胃pH低与蹄部评分之间存在直接关系。如果管理不当，产犊前低NE(L)和产后高NE(L)可能会增加亚临床蹄叶炎的风险。
