Yes you could do lamb, but again because your boy is a large breed, they have strict dietary requirements til roughly 10 months of age to prevent growth disorders.
this is a 2 yr old list of foods that are LBP appropriate. I would email the company’s to confirm the as fed calcium and phosphorus levels however: https://docs.google.com/a/selu.edu/file/d/0BwApI_dhlbnFTXhUdi1KazFzSUk/edit?pli=1
once you have those numbers plug them into the calculator on this thread about large breeds: /best-dog-foods/best-large-breed-puppy-food/
If the ratio falls between 1.1:1 – 1.5:1, it’s safe for large breeds.
