Melendez P, Goff J P, Risco C A, Archbald L F, Littell R, Donovan G A
College of Veterinary Medicine, University of Florida, Gainesville, 32610, USA.
J Dairy Sci. 2004 Dec;87(12):4182-9. doi: 10.3168/jds.S0022-0302(04)73562-6.
The objective of this study was to determine the effect of a monensin controlled-release capsule administered intraruminally at dry-off on rumen volatile fatty acids, NH3, lactate, pH, and energy blood metabolites in transition dairy cows fed Florida typical diets. In March 2003, 24 cows (10 primiparous and 14 multiparous) dried-off 50 to 70 d before expected parturition were randomly assigned to a treatment (n=12, oral capsule of monensin) or a control group (n=12, no capsule). Both groups received the same diet and were exposed to the same environment and management conditions. At assignment, at 21 d before expected parturition, at calving, and at 7, 14, and 21 d postpartum, blood samples were taken and body condition scores were determined. At 10 d postpartum, rumen and blood samples were obtained in the morning before the first feeding and at 2, 4, and 6 h after feeding. Serum nonesterified fatty acids (NEFA), beta-hydroxybutyrate (BHBA), and glucose were measured. Rumen samples were analyzed for concentrations of acetic, propionic, butyric, L- and D-lactic acids, and NH3. Data for rumen and blood metabolites were analyzed by ANOVA, mixed models for repeated measures. Volatile fatty acids were not different between groups. Multiparous treated cows had a significant reduction in rumen NH3 at 6 h after feeding. Treatment with monensin significantly increased body condition score at calving in multiparous cows. During the postpartum period, NEFA and BHBA were noticeably lower in treated than in control primiparous cows. This difference was not observed in multiparous cows.
本研究的目的是确定在干奶期经瘤胃内注射莫能菌素控释胶囊，对采食佛罗里达典型日粮的围产期奶牛瘤胃挥发性脂肪酸、NH3、乳酸、pH值及血液能量代谢产物的影响。2003年3月，将预期分娩前50至70天干奶的24头奶牛（10头初产牛和14头经产牛）随机分为处理组（n = 12，口服莫能菌素胶囊）和对照组（n = 12，不服用胶囊）。两组奶牛采食相同日粮，且处于相同的环境和管理条件下。在分组时、预期分娩前21天、分娩时以及产后7天、14天和21天采集血样，并测定体况评分。产后10天，在首次饲喂前的早晨以及饲喂后2小时、4小时和6小时采集瘤胃和血样。测定血清非酯化脂肪酸（NEFA）、β-羟基丁酸（BHBA）和葡萄糖含量。分析瘤胃样品中乙酸、丙酸、丁酸、L-和D-乳酸以及NH3的浓度。瘤胃和血液代谢产物数据采用ANOVA和重复测量混合模型进行分析。两组间挥发性脂肪酸无差异。经产处理奶牛在采食后6小时瘤胃NH3显著降低。莫能菌素处理显著提高了经产奶牛分娩时的体况评分。在产后期间，处理组初产奶牛的NEFA和BHBA明显低于对照组。经产奶牛未观察到这种差异。
