Cornell U. extension has some things to help "small dairies", which have been going out of business in New York forever.
They use a 100-cow dairy as an example of "small", which still strikes odd because 30 or so was the average when I grew up (we had 12). Though in surfing the web the other day I ran across claims of being able to handle milking of 200-300 cows with one person (maybe on the Wikipedia talk page, not sure). That's not Moore's law of transistors, but it's a better improvement in productivity than higher education.
Cornell also has a map showing "Small Plants for Pasteurized Milk, Yogurt, etc.). and a set of benchmarks (size of farm, milk per cow, acres per cow, etc.). I'd think breed would be important: one farm has 25,000 lbs per cow, which has to be Holstein, another has 13,000 lbs, which has to be Jersey or Guernsey or whatever.