Q:

Meat-and-bone meal given to animals make them haram? 

First of all, sorry for the inaccuracies of my question or terminology, since I'm not Muslim myself and I ask it out of curiosity. 
I became aware that in Europe it is allowed to give some animals met-and-bone meals (in a dried powdered form) as addition to the normal meal.  The amount of such meal originated from the same species as the receiver is limited by law to very low amounts, therefore it is common to use other animals as source (in any case, the percentage of this meat-and-bone meal on the final meal remains very small). 
In other words, we have pigs eating "powdered" cows and chickens, and chickens eating pigs, and so on. 
Does this make the resulting chickens haram/forbidden? 
Before simply answering "the chickens are not slaughtered properly anyway", I would like to point out that the question is limited to the food, not to the rest of the procedure.  Moreover, I'm not sure, but I expect many Islamic butchers to buy live chickens grown industrially and to slaughter them themselves (to be able to have a reliable and controlled source), the question may still be relevant for them. 
Back to the question: I would expect the chickens to be allowed, since their bodies completely processed the food they receive and probably no trace of pigs is left, but that is my opinion. 
See also: Gelatin capsules from pig ash \ bones

A:

I would expect the chickens to be allowed, since their bodies completely processed the food they receive and probably no trace of pigs is left, but that is my opinion. 

Indeed, the najis (impurities) undergo a chemical change in the animal's digestive system, which is an important factor:

For even though these feeds are considered haram for us to consume, once they are fed to the animals and fish they have undergone chemical transformation.  Thus according to jurists because of istihalah or chemical transformation they cannot be ruled as strictly haram. --  Sheikh Ahmad Kutty, sourced from AboutIslam.net

Scholarly attitudes seem to be generally borderline.   It's not great to eat their meat, but there won't be much impurity, and it's impractical to wholly eliminate these impurities.   Some other fatawa:

AskImam.org ("If, however, the main diet of the livestock consists of impure substances... it will be impermissible (makrūh tahrīmī) to consume them according to the Hanafī Mazhab... According to the Shāfi‘ī Mazhab, if the flesh of the animal changes as a result of its diet on impure materials, it is slightly disliked (makrūh tanzīhī) to consume.") 
Qibla.com ("any livestock... fed with impurities other than animal excrements, does not make it Haram or prohibited for Muslims to eat.") 

These touch on the matter of jullalah (filth-eating animals).   Whether it's acceptable to eat these animals is debatable, and generally low levels of haram feed is regarded as not making them jullalah. 

In conclusion, the use of animal by-products to supplement animal feeds does not appear to make the feed “jullah” hence the animal eating this feed should not be considered as Jallalah.  While there is some difference of opinion on whether Jallalah animals are Haram, many consumers prefer not to consume the animals that have been fed animal by-products. --  Supreme Council of Halal Meat in Australia Incorporated

In regards to the consumption of jullalah fish:

The position of the majority is not the emphatic prohibition but karahah (disliking).  If we add to this the difficulty and hardship that may befall millions of Muslims if we decree the consumption of all main-stream market fish haram, then I would certainly refrain from saying that.  I believe that Muslims may consume this fish. --  Dr. Hatem Al-Hajj, sourced from AboutIslam.net

