I have visited an egg factory about 10 miles from my home and I can tell you the hens appear and act no different than the ones I have seen in exhibition cages, backyard coops or in freerange situations. They are well cared for and I really do not think a chicken has the emotional capability of sadness or any other emotion but instincts, humans are the only species that can produce tears... of joy or sadness. I can assure you that I have seen more hens neglected in a backyard situation by that I mean getting ran over by cars, eaten by predators, unchecked diseases, living in mud, fed improper nutrition getting beaten off the prime feed by older hens. In the Islands there are wild jungle fowl and they are eaten by almost anything that can catch them, the roosters are continuously fighting each other and they usually die, disease will wipe out an entire flock. So if a hen actually could think the thoughts you suggest she may be saying "hey its' not so bad all I do is lay an egg and someone feeds me gives me water and lots of company".