Debby, I don't know much about this but have done some reading. Here is information from poultry specialists at the National Center for Appropriate Technology (NCAT). It is a 12 page pdf and takes a little while to load because of the color photo's. Unfortunately, most of the chicken photo's are of dressed birds in the supermarket
.
http://attra.ncat.org/attra-pub/PDF/labelrouge.pdf
Label Rouge is a labeling program a little like "Certified Organic" in the US. The authors tell us that, "'Quality labels' like Label Rouge provide information to consumers on product attributes such as taste, health benefits, and nutrition, as well as on social issues such as support of local farms."
"There are also Label Rouge ham, sausage, eggs, rabbit, and cheese products."
Label Rouge uses specialty broilers for outdoor production. "In Europe the slow-growing genetics are mainly supplied by the poultry breeding companies SASSO (3) and Hubbard-ISA (4). . . At the time of this writing, SASSO and Hubbard-ISA genetics of this type are not available in the U.S."
That has probably changed since this was written 6 years ago. The authors do talk about "Redbro," a Hubbard bird that IS available in the US. Hubbard now says that, "The JA 57 and P6N, mated with "slow growing" males or "differentiated growth" males fulfil the needs for the French "Label Rouge" or European "Certified" broiler." Maybe you can draw the genetic threads of that story together and where Redbro fits in. There's a little conversation on the "Meat Birds ETC" forum in one of the threads about alternatives to the Freedom Rangers and Redbro is discussed.
Here's a link to the Hubbard bird info. You can also click on "Color - Slow Growth" on the sidebar.
I hope this helps.
Steve