We're backgrounding steers. They come in at 600lbs and leave at 1000lbs. Guy who owns them finishes them out to 1350-1400. Typically when they come in, we let them eat hay until we have enough to make it worth working. That may be anywhere from 70-200 depending on what we're doing or how fast they're coming in. Usually no more than 3 days. Then we work them with One Shot, 7 way, Dectomax/Ivermectin, Nasalgen, and Synovex or Ralgro Implants. Also castrate any that the previous owners missed and cut the tails if it's fall. Cutting the excess hair off the tails prevents them from turning into bowling balls that hurt their legs.

Right away we put them in the lot and start them out on a low grain mixed ration to start working them up to 20lbs of grain. We also put free choice hay out for the first week or so.

We've never seen much gain from pre-treating them all. You've just got to ride or walk the pens at least once a day and better twice for the first three weeks or so and watch to see animals that don't look right. Hanging head and ears, coughing, etc. Mycotil seems to work best for us. Never had any luck with Nu-Flor. If you get them early your odds of losing them go way down. Typically we are well under 1% death loss. Less than 5 or 6 out of 1,000 is not uncommon. I've heard claim that for our northern climate and varying temperatures anything under 2% is good. Definitely not for the guys who don't want to work on the weekends.

Those might be bigger animals than what you're questioning, but we follow the same procedure with our 500lb calves we buy to put on grass for the summer although they don't wind up on nearly as high of grain in the ration.