In researching vent pecking I found this string (although some of it is older) and would like some opinions. About a month or two ago, when the colder whether started to settle in, I started having an issue with one hen going around ripping feathers out of the others and eating them. I did research, increased their protein by increasing the BOSS they get with their corn and oat scratch and giving them mealworms every other day as well as their free choice organic layer pellet grain and treats such as cabbage (whole, hung from a peg), squash, broccoli, any veggie goody leftovers we have. We also increased their pen size from 8 x 12 to 8 x 16 and another 4 x 8 under the coop. The coop size is 4 x 8 and we have 9 hens, 4 barred rocks and 5 buff orpingtons (all born May 3, 2012). Well a barred rock is the aggressor and after treating two hens (both orps) for feather plucking in the base of the back near the tail and separating the nasty hen for 2 weeks we reintroduced her. The pen size increase was done in her absence. We also added heavy branches for climbing and I fill 3 treat balls a day with BOSS, oats, corn, grain mixture to keep them busy (in addition to the produce and mealworms).
Today I found a hen (a rock) with her vent area ripped up, all feathers gone, layers of skin gone and bleeding. I immediately took her out, washed with Betadine and applied Blu-Kote. She is acting fine, eating, drinking, so hoping she will heal ok. I also removed the nasty hen I suspect is at it again. This was all found at sunset when I was tucking them in for the night (they spent much of the day in the coop and under it as we got a foot of snow last night). The close quarters could have been the catalyst but I'm thinking of getting rid of this hen even though she is a good layer because if she is the only one really doing this I think it is the best solution. No one else looked damaged but I will be observing them multiple times tomorrow just to see if anyone else is pecking. Any advice is welcome, these girls are supposed to be a relaxing hobby for me and lately it is NOT! Help!
Coop and pen.

Offending hen

Today I found a hen (a rock) with her vent area ripped up, all feathers gone, layers of skin gone and bleeding. I immediately took her out, washed with Betadine and applied Blu-Kote. She is acting fine, eating, drinking, so hoping she will heal ok. I also removed the nasty hen I suspect is at it again. This was all found at sunset when I was tucking them in for the night (they spent much of the day in the coop and under it as we got a foot of snow last night). The close quarters could have been the catalyst but I'm thinking of getting rid of this hen even though she is a good layer because if she is the only one really doing this I think it is the best solution. No one else looked damaged but I will be observing them multiple times tomorrow just to see if anyone else is pecking. Any advice is welcome, these girls are supposed to be a relaxing hobby for me and lately it is NOT! Help!
Coop and pen.
Offending hen