Shouldn't be that much in intestines... they may be just sitting and that can slow digestion.
Also if they starve too long there may be intestinal weakness. I had intestines break as I was pulling out when I withheld food for 24 hrs
https://www.poultryworld.net/Home/G...wal-minimises-losses-at-processing-WP009469W/
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I've accidentally withheld food for about 24 hours a few years ago, because it took longer than expect to process as it goes sometimes and they definitely seem to have problems with it. I was seeing white sticky mucus coming out of the mouths of the birds that went that long without feed while they were hanging upside and during the bleed out. I never had any intestines rupture on me because of it, but I like to do no more than 12 hours without feed after that. It just seemed like they started to suffer. I don't restrict feed for my broilers and I think they were especially hungry because of that - after eating every moment of every day except for at night and then having to go 24 hours.