Skip to main content Accessibility help

The rumen simulation technique (Rusitec) as a method to determine the in vitro carry-over period following monensin treatment by measuring volatile fatty acid molar proportions

  • E. D. Mackintosh (a1), R. H. Phipps (a1) and H. J. Grubb (a1)


Ruminant and ruminal responses to feeding the gram-positive ionophore, monensin, have been researched extensively over the past 20 years. A proportion of many such in vivo experiments have used a change-over design. In doing so, the researcher either paid no attention to or was reasonably confident that any possible carry-over effects would have dissipated. Evidence does exist which leads to an estimation of duration to maximum treatment effects but such comparable evidence surrounding the duration of carry-over to monensin treatment is not available.

An in vivo trial was proposed at the Centre for Dairy Research (CEDAR), to investigate the ruminal effects of feeding monensin to lactating dairy cows with 4-week periods of which 3 weeks was for change-over and adaptation. Therefore, before conducting such an expensive experiment, in terms of both time and money, an in vitro study using the rumen simulation technique (Rusitec) was carried out to determine if 3 weeks was considered adequate to eliminate carry-over effects when measuring volatile fatty acid (VFA) molar proportions.



Hide All
Czerkawski, J. W. and Breckenridge, G. 1977. Design and development of a long-term rumen simulation technique (Rusitec). British Journal of Nutrition 38: 371384.
Jalc, D., Baran, M., Vendrak, T. and Siroka, P. 1992. Effect of monensin on fermentation of hay and wheat bran investigated by the rumen simulation technique (Rusitec). 2. End-products of fermentation and protein synthesis. Archives of Animal Nutrition 42: 153158.
McDougall, E. I. 1948. Studies on ruminant saliva. 1. The composition and output of sheep's saliva. The Biochemical Journal 43: 99109.
Mackintosh, E. D., Phipps, R. H., Sutton, J. D. and Wilkinson, J. 1996. Effect of monensin on in vitro semi-continuous rumen fermentation in the rumen simulation technique (rusitec). Animal Science 62: 680 (abstr.).
Mackintosh, E. D., Phipps, R. H., Sutton, J. D. and Wilkinson, J. 1997. The interactive effects of monensin treatment and diet composition on in vitro semi-continuous rumen fermentation using Rusitec. Proceedings of the British Society of Animal Science, p. 202 (abstr.).
Wallace, R. J., Czerkawski, J. W. and Breckenridge, G. 1981. Effect of monensin on the fermentation of basal rations in the Rumen Simulation Technique (Rusitec). British Journal of Nutrition 46: 131148.


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed