I would advise to test a possible effect of probiotics (or antibiotics) on animals performance under standardized suboptimal conditions, as under optimal (laboratory type) conditions the limit of the animal performance is often in the genetics of the animal. Then there is simply no room for further improvement.

Unfortunately I am not aware of such a good working model situation.

In vitro tests are probably also generally giving already the best possible result, so also there some room for improvement should be present, in order to be observed

There are different methods for meauremenu in_vitro nutrient digestibility like in pepsin  digestibility that can be used for evaluauion of protein quality in processed feed. In my opinion,  you should better to meeasure the digestibility of the feed nutrients after adding the probiotics  to feed in natural condition( in_vivo condition). You can slso measure the potential of your probiotics by adding it to specific cultures, in certain condition and evaluate the  colony formating unit of bacteri in production of specific componds in media. Good luck.

Thanks to all for suggestions. Got the better protocol for it. We only wanted to screen our 21 lab isolates of S. cerevisiae for their effect, first by in vitro and then in vivo 

Hello!

We can advise you to study the activities of pancreatic enzymes (amylase, lipase, proteases) in the duodenal digesta since it was established that the pancreas can effectively adapt itself to the feed quality; supplementation of a diet with an additive will affect secretory function of the pancreas and corresponding intestinal enzyme activities.

Sincerely,

Dr. V. Vertiprakhov e-mail: [email protected]