Institute of Dairy Science, MoE Key Laboratory of Molecular Animal Nutrition, College of Animal Science, Zhejiang University, Hangzhou 310058, P. R. China.
J Dairy Sci. 2012 Oct;95(10):5978-84. doi: 10.3168/jds.2012-5499. Epub 2012 Aug 23.
Six rumen-fistulated dairy cows were used in 2 trials to validate the technique for the collection of ruminal fluid by an oral stomach tube (OST). Trial 1 was conducted to compare the differences of ruminal fermentation parameters among rumen sites (cranial dorsal, cranial ventral, central, ventral, caudal dorsal, and caudal ventral). The ruminal fluid was collected once per day for 3 consecutive days through rumen cannula (RC). The samples were analyzed for pH, volatile fatty acids (VFA), ammonia N, sodium, potassium, calcium, chloride, and phosphorus concentrations. The ruminal fermentation parameters varied significantly among rumen sites. Compared with the central or ventral rumen, the cranial dorsal rumen had significantly higher pH, ammonia, and sodium concentrations and lower acetate, propionate, and butyrate concentrations, indicating that the sampling site may be one of the main factors contributing to the difference in ruminal fermentation parameters between the samples collected via the OST and RC. In trial 2, the fermentation parameters of ruminal fluid collected via OST at 2 insertion depths (180 or 200 cm) were compared with those of ruminal fluid collected via RC (ventral sac). Ruminal fluid was collected once per week at 5 to 6h after morning feeding. When the OST was inserted to a depth of 180 cm, the OST head was located in the cranial dorsal (atrium) of the rumen. The ruminal fluid collected via the OST had higher pH and sodium concentrations but lower VFA, potassium, calcium, and phosphorus concentrations than that collected via RC. However, when the OST was inserted to a depth of 200 cm, the OST head could pass through the front rumen pillar and reach the central rumen for sampling. No differences were found in pH, VFA, ammonia N, and ion concentrations between the samples collected via the 2 sampling methods. These results indicated that the OST should be inserted to reach the central rumen to obtain representative rumen fluid samples.
六头瘤胃切开奶牛用于两项试验，以验证经口腔胃管（OST）采集瘤胃液的技术。试验 1 旨在比较瘤胃不同部位（颅背侧、颅腹侧、中央、腹侧、尾背侧和尾腹侧）之间瘤胃发酵参数的差异。每天通过瘤胃套管（RC）采集瘤胃液一次，连续采集 3 天。分析样品的 pH 值、挥发性脂肪酸（VFA）、氨氮、钠、钾、钙、氯和磷浓度。瘤胃发酵参数在不同瘤胃部位之间存在显著差异。与中央或腹侧瘤胃相比，颅背侧瘤胃的 pH 值、氨氮和钠浓度显著较高，而乙酸盐、丙酸盐和丁酸盐浓度显著较低，表明采样部位可能是导致 OST 和 RC 采集的样品之间瘤胃发酵参数差异的主要因素之一。在试验 2 中，比较了 OST 在 2 个插入深度（180 或 200cm）下采集的瘤胃液与 RC（瘤胃囊）采集的瘤胃液的发酵参数。每周在早上喂食后 5 至 6 小时采集一次瘤胃液。当 OST 插入深度为 180cm 时，OST 头部位于瘤胃的颅背侧（心房）。与 RC 相比，OST 采集的瘤胃液具有更高的 pH 值和钠浓度，但更低的 VFA、钾、钙和磷浓度。然而，当 OST 插入深度为 200cm 时，OST 头部可以穿过前瘤胃柱并到达中央瘤胃进行采样。两种采样方法采集的样品之间的 pH 值、VFA、氨氮和离子浓度没有差异。这些结果表明，OST 应插入到中央瘤胃以获得有代表性的瘤胃液样品。
