I have 2 big dogs one is 3yrs and other is 1yr 1yr keeps fighting and drawing blood not wantin to stop?

3yr breed is chow/lab 1yr breed is chow/sheppard . The younger dog is starting to fight over food which he has never done before. he is a very loving mild mannered dog any other time. The last time they fought he would not stop untill he pinned the older dog to the ground and he had drawn blood. I had to grab his collar and pull him off. What can I do to stop this behavior?