In vitro methods to evaluate the effects of plant waste products on rumen and gut microflora

The requirement of a safety use of additives in animal nutrition induced the EU to introduce a new regulation on feed additives. Organic wastes from the food/feed industry could include valuable substances to novel high value added products as additives. The objective of the present study was to screen in vitro effects of organic wastes on rumen microbial metabolism by batch incubator system (pH, ammonia N, VFA concentration, Total Bacterial Count) and on gut microbial flora from monogastrics by paper disc agar diffusion method (growth or inhibition of gut microbial flora). The results obtained by these preliminary in vitro tests have permitted to identify the substances with positive activities that will be evaluated in future in vivo trials.