Okay, I have been feeding my broilers FF since they were days old.  I have some that are at 8 weeks today and some that are at 6 weeks today.  In the last week I have lost 12 birds to flip.  I am doing nothing different than I have in previous years.  We had one today that was very lethargic so we processed it and it had ascites (body cavity full of yellow fluid).  This particular bird was very small.  Most of them have been dying in middle of the night and we find them on their backs.  I am so frustrated that I can't stand it!!  It just kills me to feed birds this long to throw them in the garbage.  Any suggestions???
 
I have done everything they suggest on raising these birds and they are also allowed to free range.
		
		
	 
 
Allowed to free range or 
made to free range?  There's a difference.  When you offer them a constant buffet of grain feeds~FF or not, they aren't going to forage aggressively at all...they may take a stroll now and again but, primarily, they will only eat, drink and rest after a certain point in their lives.  They are too heavy to do otherwise. 
 
The first batch of meaties I raised had no deaths at all and no health issues, were butchered at 11 wks and displayed healthy organs and carcasses~they were not given FF, just free range and layer mash/whole grains once a day.  They dressed out 5-6 lbs on average. 
 
The second batch had one death of a chick at 2 wks..could have been caused by our grown rooster at the time but I now doubt that.  Out of the 54 sent, one died at 2 wks of unknown causes, 3 died around the same time by drowning in the dog's bucket.  The rest thrived to be butchered at 10-13 wks...again, no health issues. 
 
Just feeding FF isn't the key to health on a CX.  It helps cut feed costs, maybe, but in reality, when you overfeed a fast growing bird and never make it exercise, the bones and muscles won't withstand that quick growth in a lot of cases. 
 
Mine free ranged in heat up to 98-99* in high humidity and traveled over 3 acres for their food....no flip.  No ascites..which indicates heart failure.  Nothing but extreme vigor and good health up to butchering.  They could roost on low roosts clear up to their processing and walk with ease, run with ease. 
 
They will, literally, eat themselves to death if you don't limit their feed and force them to exercise.  I fed in the evening so that they had to move for food all day long and were finally given food each evening...they all came back to the coop with full crops, so their foraging was considered a big success.  Saved me money on feed, yielded live and healthy birds for processing, and the meat was healthy and I didn't have any reservations about eating birds who barely make it to their second month of age. 
 
Those recommended feeding charts from hatcheries are designed around commercial poultry business protocols.  They lose birds by the end loader bucket full each day and they can afford the losses because they are growing these birds by the thousands.  A backyard person cannot afford those losses and needs to change tactics if they are going to raise meat profitably and in a healthy manner. 
 
My suggestion is to get them out on free range at an early age, feed once a day in the evening, use the FF, feed normal protein levels much like you'd give a layer flock and provide open air and shady housing.