where have my DOMS gone?

hello everyone,
so i have been weight training (bodybuilding) for 4 years  now. I am 23 years old and train 4-5 days a week depending on how busy work is. with cardio 3 times a week. I have also followed a consistent diet of low carbs and high protein/fat/dark green veg.
 
In the last 2 months i have noticed no matter how hard i train, (even after brutal 20-set leg workouts!!!) i dont seem to get DOMS anymore.
 
1. Why is this?
2. What does this mean for my training regime? Should i train even harder/heavier? Or does it mean nothing?
 
I vary my workouts regularly. I am currently training FST-7 style!!
 
Any comments/thoughts appreciated.
Chris.

i had this problem with my quads, i was doing high sets, i simply upped the weight a fair amount, and sure enough the old pain returned!

The presence or lack of DOMS doesn’t guarantee that muscle growth is or isn’t taking place. DOMS simply indicate that muscle repair is occurring. It’s usually a very good sign that growth is also occurring but I wouldn’t get too hung up on DOMS themselves, I’d concentrate more on results.
 
You didn’t mention if you are getting the results you’re training for, whether that be adding muscle mass, strength or losing body fat. If the results are coming then that’s all that matters.
 
If the results aren’t as expected and you feel you’re doing everything right then it sounds a simple case of exhaustion. Don’t panic, I’m not saying you’re knackered, your system is just in need of a good rest. Take a full week off (sound like a doctor don't I), perhaps two, depending when you took your last break to fully recharge your system.
 
 You’ll come back raring to go and the results should start happening again.
 

It's a good thing that your DOMS has gone because who wants to be sore all of the time? I'm surprised you were still getting so long after beginning training. The body prevents DOMS via the repeated bout effect - your body has become used to the punishment you have put it through and recovers faster and is less "shocked" by the workload - it doesn't mean that hypertrophy will not occur though. 
 
There isn't a clear link between DOMS and muscle hypertrophy - I could probably induce DOMS if I did a 150 tricep extensions with little of no weight but would that stimulate the muscle in to more growth than say if I did 8 to 10 reps with a very heavy weight which might not induce DOMS? 
 
I think for a lot of people DOMS is a psychological boost which makes you feel like you've really worked out your muscles but being sore and having your movement restricted for tomorrows work out is no fun IMO.

i find that i get the doms in different places sometimes more sometimes less - i rarely get them in my lats but i changed the routines around & bingo - today my legs don't hurt but last week i cried trying to sit on the loo