Rat Breeding Grow Outs cannibalizing

[Mr Scales]

Hey guys,

First I'd like to say hello! It's been a while since I've posted on this forum. Been busy with the snake collection and house remodeling.

I've been breeding rats for atleast 2 years now and have came across something I've never encountered before. It just started about 2 weeks ago. I noticed a few grow out bins had the remanents of a left over rat skin. Ok well that one must of passed and they are just doing what is in their natural instinct.
Keep in mind this is happening in only the grow out bins of small rats.

Now over the last few days upon checking on them and making sure the water system is full. I noticed several have had one of their front legs completely eaten off up to the joint of the body.
It's random in random grow out bins.

It's mainly happened with the males. But now I came across a female that was a hold back pet ( Blue Russian Double Rex Dumbo Blaze Rat)

Any one have any ideas what I maybe over looking?

Things I've thought about:

Maybe its the new bedding since eco flake is no longer Available I've since Switched to natural wood shavings at 12.99 a 5cu foot bag now I was forced to switch to kiln dried pine shavings until I can find a place to order the hardwood shavings from.

I've always used Mazuri 6f rodent breeder blocks. I found the HPS Rodent diet from reptile basics to be $10 cheaper and went with that. I started with a 70% Mazuri / HPS diet blocks and worked them over slowly to fully HPS diet Blocks.

All water provided is thru a gravity fed water system. Will soon be installing a low pressure constant water supply system.

Room temps fluxuates some but holds anywhere between 70° to 73° depending on outdoor temps.

All my breeding racks are based off a daily feeding formula to make sure they are not over fed. And the grow outs have food constantly since they are growing babies of which has gotten me racking my brain why the growouts are eating the others front legs off.

I'm open to all advice, suggestions or whatever it maybe be to help figure out why these super social rats or eating each other's front legs off. Please no bashing me for something like this lol.

[Veronica]

Just hypothesizing here, but do you think that they are overcrowded? I know nothing about rats or keeping them, so it's just an idea.
Another thing to look at, maybe, is the protein content of the HPS, perhaps they feel like there isn't enough in their diet?

[Mr Scales]

I did take into consideration as a possiblity but ruled that out. There quite a bit of moving room so there is no crowding in the grow out tubs. I generally keep 10 in each tub 15 Max but those numbers generally decrease quickly for snake feed. Tubs are 28" deep 20" wide and 6" tall. Basically they are the medium concrete mixing tubs from home Depot. I've never had this problem in the past as it just crept up on me. Protien 18% fat 6% Wich is right on spot for the grow outs. The adults are on 16% protein and 6% diet and are doing great. Their not killing each other it's just several have one of the front legs chewed off. Haven't ruled out one or more culprits doing this or it's the rats themselves chewing their own legs off.