Evaluation and validation of a paralumbar fossa trans-abdominal rumen fluid sampling technique

Abstract

Evaluation of rumen fluid for pH and rumen microbes (in particular, rumen protozoa) is helpful for both diagnostic and treatment purposes. Evaluating the pH of the rumen fluid is used to confirm acute ruminal acidosis as well as subacute ruminal acidosis. Evaluation of the ruminal protozoa helps to confirm the necessity of ruminal transfaunation. Protozoa will be dead or dying if the ruminant has been ill and off-feed for some time (usually>4 days). Passage of an oro-ruminal tube is 1 method for obtaining a rumen fluid sample. However, this method may yield rumen fluid that is mixed with saliva and may falsely elevate rumen pH. The tube method also requires more time and effort. A simple means of obtaining rumen fluid is trans-abdominal ruminal aspiration. This method has been used for over 20 years by the primary investigator (Roberson), but has never been evaluated in regards to safety and efficiency. The purpose of this study was to document the methodology, determine the actual time of obtaining the sample, and evaluate any negative consequences of the procedure. Secondary aims were to determine pH and number of protozoa/40x field.