While considering crops and hanging out with the chickens, a couple other topics popped into my head. Probably worth what you paid for them 
1. Effect of feeding protocol on broodiness. We do free-feeding. Birds have access to multiple feed stations all day long. Is this in any way related to none of them EVER going broody?
2. Effect of exercise on digestion. Does the foraging movement (scratch, scratch, peck peck) help move food through the system? The Brahma and Marans hens barely scratch the ground - it's more like they pat at it while waiting for the rooster to dig up something good - but they still move their feet. One of the Langshans scratches while she's at the feeder, like a reflex.
Tax: Some good scratching (if you hear barking in the background, it's the neighbor's latest rescue puppies, wrangled from other, dog-hoarding neighbors).
1. Effect of feeding protocol on broodiness. We do free-feeding. Birds have access to multiple feed stations all day long. Is this in any way related to none of them EVER going broody?
2. Effect of exercise on digestion. Does the foraging movement (scratch, scratch, peck peck) help move food through the system? The Brahma and Marans hens barely scratch the ground - it's more like they pat at it while waiting for the rooster to dig up something good - but they still move their feet. One of the Langshans scratches while she's at the feeder, like a reflex.
Tax: Some good scratching (if you hear barking in the background, it's the neighbor's latest rescue puppies, wrangled from other, dog-hoarding neighbors).

What I've done is to report what some studies have found. It was the crop size thing that got me going because I know a bit about crop size limitations when it comes to feeding. I read at least three times the number of studies around the topics in my research. What I didn't know and this is the part I'm really interested in was that according to the studies a chicken can divert food to the crop or the proventriculus.