Duffield T, Plaizier J C, Fairfield A, Bagg R, Vessie G, Dick P, Wilson J, Aramini J, McBride B
Department of Population Medicine, University of Guelph, Guelph, Ontario N1G 2W1.
J Dairy Sci. 2004 Jan;87(1):59-66. doi: 10.3168/jds.S0022-0302(04)73142-2.
Subacute rumen acidosis is thought to be a common condition in early lactating dairy cattle; however, diagnosis is difficult. There are currently only two techniques available for measuring rumen pH under field conditions: rumenocentesis and oral stomach tube. Sixteen rumen-fistulated cows were sampled in four sites of the rumen (cranial-ventral, caudal-ventral, central, and cranial-dorsal) with a rumen cannula. Rumen pH results were compared to those obtained at the same time with rumenocentesis and with an oro-ruminal (Geishauser) probe. Rumen fluid was obtained between 6 and 12 wk of lactation. Samples were analyzed for pH, lactate, bicarbonate, sodium, potassium, and chloride. Rumen pH results were also compared to those obtained from 24-h continuous rumen pH measurement using indwelling rumen pH probes. Oro-ruminal probe samples had the highest pH values and the highest bicarbonate concentrations. Rumenocentesis samples had the lowest pH values and the lowest bicarbonate concentrations. Small differences in electrolyte concentrations were noted among rumen fluid collection techniques in the different rumen sites. The highest correlations of rumen pH were obtained between rumenocentesis and rumen cannulation (cranial-ventral), and between rumen cannulation (cranial-ventral) and the 24-h indwelling pH meter. Compared with samples obtained from the cranial-ventral rumen, rumenocentesis was more sensitive than the oro-ruminal probe in the measurement of low rumen pH; both techniques were moderately specific. The most accurate field technique was rumenocentesis. Improved field techniques are required for better on-farm diagnosis of subacute rumen acidosis.
亚急性瘤胃酸中毒被认为是泌乳早期奶牛的一种常见病症；然而，诊断难度较大。目前在现场条件下测量瘤胃pH值仅有两种技术：瘤胃穿刺术和经口胃管法。对16头装有瘤胃瘘管的奶牛，通过瘤胃插管在瘤胃的四个部位（瘤胃前腹侧、瘤胃后腹侧、瘤胃中部和瘤胃前背侧）采集样本。将瘤胃pH值结果与同时通过瘤胃穿刺术和经口瘤胃（盖绍泽）探头获得的结果进行比较。在泌乳6至12周期间采集瘤胃液。对样本进行pH值、乳酸、碳酸氢盐、钠、钾和氯的分析。瘤胃pH值结果还与使用植入式瘤胃pH探头进行24小时连续瘤胃pH测量所获得的结果进行比较。经口瘤胃探头样本的pH值最高，碳酸氢盐浓度也最高。瘤胃穿刺术样本的pH值最低，碳酸氢盐浓度也最低。在不同瘤胃部位的瘤胃液采集技术之间，电解质浓度存在细微差异。瘤胃穿刺术与瘤胃插管（前腹侧）之间以及瘤胃插管（前腹侧）与24小时植入式pH计之间的瘤胃pH值相关性最高。与从瘤胃前腹侧获得的样本相比，瘤胃穿刺术在测量低瘤胃pH值时比经口瘤胃探头更敏感；两种技术的特异性都为中等。最准确的现场技术是瘤胃穿刺术。需要改进现场技术以更好地在农场诊断亚急性瘤胃酸中毒。
