It says:
Thank you very much for your letter. If you could write in Japanese, I will be able to write our reply sooner. I need it translated...so, sorry!
I was very happy to read your letter and see the photo.
As far as I see in the photo, the red bird appears to be a purebred (authentic) Nagaodori.
I have suspicions regarding the white one, however. The reason is that I think the red and the white differ in crest (shown in drawing) and tail. However(?), I don't think that the tail of the bird should droop, even for a female.
I wonder what chicks will come from crossbreeding the red bird and the white bird--I have my doubts.
Still, I can tell that you have devoted great love and enthusiasm in raising them.
I hope you continue your work [with enthusiasm].
Nagaodori Center
# I hope it makes sense...
I put a question mark on "however" because I could not get the logic behind it--probably because I don't know anything about the fowl.
Still, I've seen these birds on TV. Good luck in your endeavor!