Rumen function between grass species

[Willstanton]

One of our farms soil varies significantly from sand rises to silt loam flats. We've been planting veldt grass on the rises and phalaris on the flats. Just wondering how much this affects animal performance when they go from one to the other within a week or few days etc.?

 

[brandonm_13]

Being unfamiliar with those grass species, I would say there probably isn't enough difference to affect digestion since the rumen microbes are set up for grass (in my case, there are mixed species in every field, even if one species is dominant). Rather, I would think the difference in digestion and growth would be more related to things like the difference in protein, carbs, proneness to bloat, fiber, etc. between the two species.