New grass for the cattle

This afternoon I spent moving the cattle to their new pasture.  They move rather willingly now.  Just a call and they are ready to go.  With all of the animals on new ground, they should be content for the week.  We will have to rotate the animals a little more quickly this round as the grass was late in growing back due to the dry July.  We are looking forward to our breeding season beginning in November.  We are going to push the calving season out a little by breeding so late, but we should have a much smaller calving window to keep an eye on the cattle.  We have chosen to breed artificially this year to lowline angus, a smaller, more efficient angus.  We are also in the process of purchasing a couple of lowline breeding animals to help our herd progress in the direction we are headed.  We want to be able to produce high quality animals on grass, not grain.  We do feed silage during the winter months, but the percentage of actual grain the animals are consuming is minimal, in my eyes, as silage contains the greens of the corn as well as the ears.  We are certainly separate from the conventional process of graining a finished animal as our beef see no commercial grains at all.  They get our grass, our hay, and our silage, all grown on our farm.  Please feel free to give us your opinions...what is a "grain-fed" animal?