I have 2 male 6 month old collie puppies not from the same litter, we hardily go a day without a fight, we have to feed them and give treats separatley now
which has stopped it over food, but sometimes they start off playing really nicely and then it turns into a nasty fight. They make a lot of noise and stand on there back legs jaws going, pawing at one another. Sometimes we leave them to stop themselves and sometimes we try to pull one off if it looks one sided. How do you breeders that keep lots of dogs together cope with situations like this and will it get better as they get older?

It's a difficult situation which is why responsible breeders rarely allow litter brother/sisters to go to the same home.  When I have run on two pups from the same litter, which I rarely do as 2 pups are 4 times the work - I always make my final decision at 6 months and seperate them.
I hope that someone else can offer you more constructive advice.

This is quite a common situation with two pups of roughly the same age, whether or not they're from the same litter, especially if they're same sex. They're now approaching adolescence, and will be trying to determine their heirarchy. Remember, dogs just don't do 'equal'! To stop the fights you need one dog who's higher ranking than the other. So you need to carefully observe which one is generally 'leader', if you like, and promote his status. Pet him first, put his food down first etc. The other is relegated to the bottom. Hopefully just doing this will ease the tension and competition between them. If it doesn't you may have to consider castrating the lower ranking one to make the difference between them even more marked.

If left to their own devices they will sort it out eventually - but it will probably result in serious injury to both, and maybe the death of one. :(

The way that most people manage harmony in multidg housefholds is not to keep dogs of the same age. 

I have five and there is two to four years between each so the natural order tends to prevail of a youngster accepting a mature adult as being above them in the scheme of things.

Hierachy does change sometimes among the adults but it soesn't seem to be so fraught as when they first find their place in the World.  My oldest bitch was quite hapy to allow her Grandaughter to assume the mantle of highest ranking canine, but equal with her.  Queen and dowager.

Hi,
Ups!!!! two males. I have experienced this years ago. Had to keep them apart!
But! it got impossible, as my children were young at the time and as the children had always been brought up with dogs, they had no fear. But!! I did!! incase they ever got caught up in between them.
So, I had to re-home the youngest, Broke my heart! never do it again.
Regards
Denese

I also had this problem with my two male rough Collies  with a year between them ....they were fine out on walks and most of  the time in the house .....we also never fed them together after thier first argument over food began we also didnt give  chews they were always given seperately their fights were always to get to the postman first or if a visitor turned up at the door  a fight would start as to who could get there first.So if we left the room we separated them if we went out one went in the hall and the other in the kitchen.Also if you watch them you can always tell  if a fight is about to start because one will not give the other eye contact.