the slow cooker and saw these weird white stringy things poking out of the meat. They look like little worms or parasites. Is the meat infested

4. How Contracting Fibers Can Suddenly “Pop Out” of a Roast
During the slow cooking process, the muscle fibers in the meat contract and lose moisture. As the fibers contract, they can sometimes push out or expose the connective tissues, which appear as white strings. This phenomenon is more likely to occur in cuts with significant marbling or bands of connective tissue.

The appearance of these fibers “popping out” can be alarming, but it is a natural part of the cooking process. Heat causes the muscle fibers to tighten, and as they do, the softer, gelatinized collagen may be pushed to the surface or become more prominent within the meat.