I got 4 goslings when they were 6 days old. They are now 12 days old. 2 saddle backs, 2 American buff. All was good until one of the buffs isn't thriving. Literally has not grown with the rest of them. Won't eat feed and I haven't personally seen it drink. I've been syringing vitamins, electrolytes, and noticed it will only eat grass I provide in the brooder. It will literally spit out the commercial feed (Mazuri) I try to force feed it. I can tell its getting weak and if it doesn't turn around soon, its not gonna make it. What else can I try?