Don't know, but can say that birds lose muscle mass very quickly - within days - when they are sick. In my experience, all my sick chickens lost muscle mass. I have found that picking them up regularly and feeling their bodies is the best way to identify problems before they show behavioral changes like lethargy. Are you experiencing this in your flock? Are there any other symptoms?
I have a 6 month old bantam pullet who began limping on 1 of her legs about 6 weeks ago. I immediately removed her from the flock and put her in a cage in my garage. At first, she wouldn't attempt to put weight on the leg at all. After about 4 weeks of increased vitamins/minerals/protein, she slightly improved. By that time, I had read about Vitamin B and leg issues...so I began giving her injections of Vitamin B. After only a couple of injections, she had improved a lot. She's now putting weight on the leg and walking with only a very slight, barely noticeable, limp. Her weight has improved...but she never did get really thin. And her face and comb have even reddened up as if she's ready to begin laying. Throughout all of this, she's been very alert, content, and all around normal. But when I was examining her yesterday, I felt the "injured" leg and noticed that it basically had no muscle mass to it whatsoever (compared to her good leg)...it was almost like there's just bone and nothing else. I'm at a loss on what the issue could be, unless it is actually is a vitamin B deficiency.
did you ever find out what was wrong with your chicken? my 11 week old pullet started limping about a week ago, and now cannot walk on her right leg. She hops w/her left w/just little bit of touch and go support from her right light. The muscle where her femur is basically non existent....just bone? We had her feces tested and she has no parasites. She does not seem to have anything broken...no bruising, swelling, bleeding. Maybe she tore a ligament or muscle. But we're wondering if she can survive w/no muscle on her femur, and if she will ever be able to walk again.
I hav a 5 month old standard Cochin pulletthat was fine showed no sign of being sick 5 days ago she come waddling out of the chicken pen unable to stand or wake wouldn't eat or drink either. I force feed her for those days. She eating n drinking on her on but she has no meat hardly at all on her upper right leg any body have a answer for me I'm syumped