We've a 40/80 here for 2 men
In spring when settling heifers in we start on maybe 16 units and as heifers settle and milk increases we move up to the full 40 for 3 ish months then drop back to maybe 24 units for last few weeks .
We do this to prevent over milking as no acrs but it does slow down...
Below 200 no infection
Above a million cow has mastitis and should be treated
200/1 million cows have infection but are fighting it and will self clear or will get full blown mastitis which will need treating
In the past I've separated cows out the herd above 500 and scc has stayed the same