Submitted to: Journal of the Science of Food and Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/4/2003
Publication Date: 1/27/2004
Citation: Leyendecker, S.A., Callaway, T.R., Anderson, R.C., Nisbet, D.J. 2004. Technical note on a much simplified method for collecting ruminal fluid using a nylon paint strainer. Journal of the Science of Food and Agriculture. 84:387-389. Interpretive Summary: The gut of animals and humans contain billions of microorganisms. In order to study these microbes, scientists often need to separate the microbes from undigested food particles by straining gut contents through several layers of cheesecloth. Unfortunately, this procedure is cumbersome, time consuming and messy. Therefore, we developed a more convenient way to collect samples of gut microbes using newly developed nylon strainers. This method was much easier and produced gut samples just as good if not better than samples obtained using cheesecloth. This new and improved collection method will facilitate the scientific study of gut microbes thus enabling scientists to learn more about how these microbes impact health and gut function.
Technical Abstract: Ruminal fluid has traditionally been collected via straining rumen digesta through multiple layers of cheesecloth. Unfortunately, this technique is cumbersome, time-consuming and is not ideal for maintaining anaerobiosis. The objective of this study was to compare ruminal fluid collected by straining through cheesecloth or through nylon mesh paint strainers. Ruminally fistulated Holstein cows (n=3) were sampled on consecutive days and ruminal contents were strained through either cheesecloth or fine mesh paint strainers. Ruminal fluid obtained through cheesecloth or a mesh strainer was analyzed for dry matter (DM) (1.94%+/-0.56 vs 2.26%+/-0.19, respectively) (P > 0.05) as well as neutral detergent fiber (32.2%+/-8.7 vs 33.6%+/-8.8) (P> 0.05) and acid detergent fiber (22.0%+/-5.5 vs 23.0%+/-4.3) (P > 0.05). Ruminal fluid obtained through both methods was anaerobically incubated in duplicate tubes containing tryptose, Sigmacell 50 or starch. There was significant (P <0.05) variation between animals, but no difference (P > 0.05) between ruminal fluid strained through cheesecloth or nylon paint strainers as indicated by volatile fatty acid (VFA) production, NH3 production from tryptose (77.0+/-5.9 vs 76.8+/-8.4 mM, respectively), specific activity of ammonia production (SAAP) from tryptose (23.5+/-7.3 vs 18.1+/-4.2 nmol/mg protein/min, respectively) or MPN of total anaerobic bacteria (1 x 10**12 vs 8.6 x 10**11 cells/ml, respectively). These results indicate that fine mesh nylon strainers can be used instead of cheesecloth to collect ruminal fluid.