I have been running stockers on a small scale just like you want to do for the last 5 years and have learned a lot. Let me tell you!!!
1. Most important, vacine. Your going to invest around $17000 dollars on these stockers, would you buy a car for $17000 and not buy insurance for it? Your only insurance for these stockers is vacine and good fences.
2. Fences, these stockers are going to be wild, some may not be weaned, if there is a way to get out they will.
3. I'm in Nebraska, and have good grass, I've averaged 1.6 lb gain per day last five years. Some averaged 2.5 some averaged .9.
4. Buy light. Less than 500 lb. My expericence is a 425 lb bought the same day as a 550 lb steer will weigh about the same in 5 months. Don't know why other than a 425 lb steer grows more? Just my expericence.
5. Fly control. This adds weight very cheaply.
6. Little bit of corn every other day. I'm talking little bit. 5 gallon bucket per 15 head. I do this cause it makes them much tamer and easier to catch when, and I say when they get out. Corn is very expensive, but to me cheaper than chasing them or losing them.
7. Keep them locked up in corrall for the 1st week. This will get the ones that aren't weaned to settle down, and most of your sickness is going to happen in that first week and is way easier to treat if you already have them caught and ready to treat them in your head gate.
8. Head gate. Gotta have one. Don't need a $3000 head/gate/squeeze chute, but I do think you need a head gate to treat the cattle yourself.
9. I would be very carefull hearding them to market. They will still be on the wild side.
I'm not sure why stockers are so wild, I think most of it has to do the way they are treated at the sale barn before you buy them. They go thru alot stess in a couple days.