Animal Welfare Professionals

Hi does anyone have any suggestions and how I can stop my Lexi from chasing the chickens and wanting to eat them? 

Also I can not let her off leash when the chickens are out and when the chickens are put up in there coop Lexi goes and barks at them. 

With my pups it was basic rewards-based obedience first and then a lot of work on “leave it”, which is taught in most beginner classes and second most important command to me to teach after “come”. 

I haven't done this training but Sophia Yin's training methods and advice are top-notch. Here's one of her blog posts that may help:  https://drsophiayin.com/blog/entry/how-do-i-train-my-dog-to-stop-chasing-the-chickens-cat-rat-2/   Good luck!