That pink powder on seed corn is most likely a fungicide for disease prevention, probably Captan. Somehow the thought of a herbicide on seeds meant to sprout sounds kind of strange but maybe. But whatever it is you should never eat anything you buy as seed. Many of them are treated for disease prevention or to break dormancy. They use some really nasty stuff on seed potatoes to help them break dormancy for example.
That corn from the field will not have anything like that in it. It should be perfectly safe for the chickens to eat and it should germinate and grow. The odds are really high that it is a hybrid, but it was not mentioned that it was “field corn”, just that it was corn. Most garden corns are hybrid too but there are a few that are not. Dad grew a white sweet corn that was not hybrid and of course you have popcorn and Indian corn, butt practically all corn is hybrid, field or sweet.
In any case it should grow and probably produce. Since it is almost certainly to be a hybrid you don’t know how well it will produce. It could be great, it could be horrible. It will likely be inconsistent. It’s always fun to try something like that to see what you get. You could talk to the neighbor to see what it is.
If you really want to grow corn for your chickens you are probably better off feeding that corn to your chickens and getting some seeds for dent corn or field corn so you know what you are dealing with. There are a few people on the sister gardening site
http://www.theeasygarden.com/ that could help you with varieties and where to get seeds. Or if you have a local Mom n’ Pop gardening store near you try chatting with them. Those people are normally pretty good and their seeds will be a lot cheaper than ordering online.