Plaizier J C, Krause D O, Gozho G N, McBride B W
Department of Animal Science, University of Manitoba, Winnipeg, MB, Canada R3T 2N2.
Vet J. 2008 Apr;176(1):21-31. doi: 10.1016/j.tvjl.2007.12.016. Epub 2008 Mar 10.
During subacute ruminal acidosis (SARA) rumen pH is depressed for several hours per day due to accumulation of volatile fatty acids and insufficient rumen buffering. Surveys suggested an incidence of SARA of between 19% and 26% in early and mid-lactation dairy cows. Causes of SARA include feeding excessive amounts of non-structural carbohydrates and highly fermentable forages, and insufficient dietary coarse fiber. Consequences of SARA include feed intake depression, reduced fiber digestion, milk fat depression, diarrhea, laminitis, liver abscesses, increased production of bacterial endotoxin and inflammation characterized by increases in acute phase proteins. The increase in endotoxin is similar among methods for SARA induction, but depends on the diet fed before induction. Increases in acute phase proteins vary among methods of SARA induction, even when the methods result in similar rumen pH depressions. This suggests that the inflammatory response might not be solely due to bacterial endotoxin in the rumen.
在亚急性瘤胃酸中毒（SARA）期间，由于挥发性脂肪酸的积累和瘤胃缓冲不足，瘤胃pH值每天会降低数小时。调查表明，在泌乳早期和中期的奶牛中，SARA的发生率在19%至26%之间。SARA的病因包括饲喂过量的非结构性碳水化合物和高度可发酵的草料，以及日粮中粗饲料不足。SARA的后果包括采食量下降、纤维消化减少、乳脂率降低、腹泻、蹄叶炎、肝脓肿、细菌内毒素产生增加以及以急性期蛋白增加为特征的炎症。在SARA诱导方法中，内毒素的增加情况相似，但取决于诱导前饲喂的日粮。即使SARA诱导方法导致相似的瘤胃pH值降低，急性期蛋白的增加在不同方法之间也有所不同。这表明炎症反应可能不仅仅是由于瘤胃中的细菌内毒素引起的。
