If you need to tube feed, these threads have some very good info:
https://www.backyardchickens.com/t/...cken-and-give-subcutaneous-fluid#post_9910754
http://forum.backyardpoultry.com/viewtopic.php?t=7933
https://www.backyardchickens.com/t/...cken-and-give-subcutaneous-fluid#post_9910754
http://forum.backyardpoultry.com/viewtopic.php?t=7933