Rumensin is used for improved weight gain and feed efficiency.
To put it in perspective the energy benefit from the recommended rate of Rumensin included in feed is equivalent to feeding stock 0.5 to 1kg of molasses per day.
Trials resulted in average weight gains of 90grams/head/day where Rumensin was added to a supplement versus the control group on the supplement alone.
Clinical and commercial trials have shown young cattle have faster growth rates it also aids in the controlling of Coccidiosis related illness in calves and weaners.
In summary, adding Rumensin to dry lick will cost an additional 1 cent per head per day but will result in an additional 60 to 120 gms per head per day in weight gained, due to increased energy gained from the benefit of Rumensin.