Chicken Died

Hi All

One of my chickens died last night and I'm trying to figure out what happened. She had started to lose some of the feathers on her neck about a week ago, and was acting a bit off during that time. I thought she was just molting, but since she was only 6 months old, that probably wasn't it. I saw her kind of burrow into the bedding and lay there during the day like she was very tired. Her vent looked normal- no feather loss or swellling, and I couldn't see anythign else on her. I'm not sure I did a thorough enough check to rule out egg binding. I really wish I would have done more. Anyway, I don't know if I sure we should be worried about the rest of the flock. They all seem energetic and fine, but I am not sure I know what I'm doing.

They are all around 6 months old and are currently eating organic layer feed plus scraps. They get out to free range about every other day. The chicken that died was a New Hampshire Red, and the rest in our flock are different breeds (black sex link, red sex link, buff orpington). I am in Utah, and it has been cold here- (freezing at night), but they do have a heat lamp to keep the coop to about 55°F.

Any thoughts on what I should be looking for? Thanks!

 

Thanks for the tips! Hopefully everyone else will be fine.