I have fed a Prey Model diet since bringing Newman home at 10 weeks,
His growth has been steady, and he remains lean feeding him at 10 % of his adult body weight.
We feed mainly beef (heart, tongue, and ground mixed grind)chicken, pork, liver and all organs. I buy grass fed beef, pastured pork and chicken..it's expensive but I'm happy with this choice. He also is fed raw egg with the shell and a good grade salmon oil 3 to 4 times per week. For training treats we give dried liver or chicken hearts.