sc trojans, and all = How do you feel about grass fed Bison (which I use quite a bit) and Venison? I use lamb a lot but also the Bison, Deer, Wild Salmon, free range poultry, etc. along with the organic veggies. This topic is never ending and always of great interest to me.
Grass fed Bison should be great - what a great resource to have. Grass fed meats are the best you can provide a dog and far healthier than grain fed animals. The omega 6: omega 3 ratio in grass fed is generally 3:1 - ideal. Whereas in grain fed beef for instance it is more like 20:1 - not good. Free range is also ideal for the same obvious reasons - they should be eating more grasses and natural product.
Lamb is great to provide in moderation - it is very fatty and high in copper so not something to feed on a constant basis and not all dogs do well on it. But if your's does, great.
As for game meats, like Venison, it depends on your source. As long as you are purchasing from a trusted source or a commercial means, then all good and safe. Game meats can be problematic on a raw basis however if wild and hunted without known health history - parasites have already been covered so I won't go into it. Freezing doesn't cut it on game meats. Do some searching on reliable sources for what it takes to kill various parasites and worms, such as this one:
http://en.wikipedia.org/wiki/Trichinosis You'll fine that freezing works well for pork and Trichinosis - but has not proven effective for game meats. These must be cooked thoroughly if the health history and source is unknown to truly be safe and trustworthy (By the way, the freezing requirement when it is effective is several days, often as many as 14-20, to effectively kill)
Wild Salmon is good as long as it is cooked - NEVER feed raw salmon - very dangerous to dogs and potentially toxic with a fluke they carry naturally. Freezing doesn't work on this one either.
Organic - even better - if you can swing it, go for it.