To me, your hen's poo indicated being over-heated and/or illness. Broody poo is big, thick, and especially large in content. Thin and runny poo is not a good sign. You had her high in the rafters, is it possible she was too warm in that area?
Also, I keep hearing it repeated that hens can brood themselves to death as if this is a natural occurrence and something that we poultry managers need to regularly protect our brooding hens from. However, It has been my experience that a healthy hen does not starve herself to death while brooding. Hens are designed to brood and withstand brooding. Unless a hen has developed a worm overload, external parasites, or has very poor food/water support during the brood, (all things to manage and maintain during the brood), she will not succumb to the ills of brooding in and of itself.
I do ponder the stamina of commercial layer breeds, such as RIRs, and hybrids for brooding. Broodiness has been genetically selected out of them, but occasionally you'll get one who does have enough hormone imprint left that she will undertake a brood, often half-heartedly. Typically they will play at brooding, sulking, rather than really committing to a good brood. However, doing so may lower their immune system enough that something latent kicks in.
I have had a couple of sulky brooders in my large fowl commercial breeds, but they snapped out of it to return to full health with a little encouragement. However, I had one lingering sulky/broody girl waste away and eventually die, even after encouragement and support. After viewing a multitude of healthy broods, and several unhealthy broods, I have come to the conclusion that this gal brooded and died from poor health rather than true broodiness.
I suspicion what is mistaken for a normal brood is sometimes actually an unhealthy brood brought on by un-natural hormonal imbalance and/or underlying disease.
Curiously, I know that in commercial breeds, ovarian tumors are very common in laying hens by the age of 2 years (which is why the industry culls at 2 years of age). One article states: "These tumors [in poultry] are so prevalent that scientists studying human ovarian cancer use chickens in their research. A study in 2005 of 676 four-year old laying hens determined that 45% had tumors! 18% of those were adenocarcinomas." (cited below)
Which causes me to ponder even further that there may be a link between these common ovarian tumors and an unhealthy, wasting brood.
I suspicion ovarian cancer was a possible culprit in that one hen. While she appeared to be truly broody at the beginning, she was especially sulky, lethargic in her brood, then weakened and wasted. No manner of encouragement or care helped. Once you see it, this wasting brood is not like a normal brood but something truly more sinister. I therefore wonder if the ovarian tumor causes a trigger of hormones which sets them into an unhealthy brood, then they slowly succumb to weakness and eventually death as their stressed immune system cannot fight off the growing, cancerous tumors.....just totally guessing as I did not do a necropsy on the hen, but I highly suspicion tumors present as her abdomen was more distended, typical of the tumors created by ovarian cancer. (Something I noticed but did not understand at the time.)
Other underlying illnesses, like slow growth Mareks, can be triggered by stress, such as brooding, and cause a slow wasting and weakness as well.
So while I am sympathetic to those who feel their hens need to be closely monitored for brooding behaviors, with significant daily intervention, and I know brooding is definitely a marathon sat by the hen and needs good support like any athlete should receive, I remain skeptical that poor health/starvation/wasting is the nature of normal brooding in itself.
Just thoughts...perhaps ramblings....in response to my continued observation that a healthy hen will brood and come out fine without a lot of human intervention but only reasonable support and maintenance.
Have any of you other experienced broody keepers noticed anything of the same kind?
@varidgerunner I know you've contemplated the same thoughts with your more wild type games having more of the natural instinct and stamina to brood
I have contemplating a lot of these things. And, I have seen birds that would "brood themselves to death". I went to a swap and picked up some bantams for a guy that lives close to me. They were some blend of cochin and d'uccle from their looks. I kept tabs on them, they did pretty good for six months or so, then they started brooding. It was a trio, both hens went broody, one successful, the other did not leave the nest, eggs didn't hatch and when he threw the eggs away she sat on nothing until she died. The other one lost her chicks, sat on rocks, wouldn't quit, so he gave her some eggs and she sat on them and was just laying there dead. Had food and water just feet away, wouldn't get off and eat and drink. Pretty disappointing, but how much sympathy can you have for something that died with food and water in reach.
When we select for things like fancy feathers, we could be inadvertently selecting away from good instincts. When we select for high egg production, we definitely select away from the brooding instinct. When one pops up, it is likely missing chunks of it's instinct. This is what makes some of them quit early, or display un-natural behavior, like not leaving for water. Ovarian problems can cause weird hormonal swings, they might make a bird turn broody, or they might make one start to crow. Definitely makes them not live as long, my birds can go easily ten years, raising broods most of that time, or even longer. I have talked to people who had 15 year old birds. Selecting for endurance, has it's advantages, and the self preservation instinct would override the maternal instincts in any bird with proper instincts. Mine will brood a lot, but they won't brood if anything is wrong with them, and I don't think they would harm themselves brooding.
I think the true instinct for brooding requires catalysts to activate it. One of these catalysts is heat. I think some of the breeds with the feather foot mutation have filled a broody niche because of the increased insulation of their feet. They are more prone to be triggered. My Ga Noi influenced birds have sparse feathering, tight and brittle. They have strong brooding instinct, but they are not much interested until it gets hot out. My bankivoid gamefowl, (American/OEG) tend to tolerate cooler weather to sit in, but none of them will start in the dead of winter. Winter gives them all the break they need, if you can call winter a break.