is it halal to eat meat of the animals who are brought up whole life with the feed which contains chicken feaces and feathers

To buy or sell feed that contains impurities such as feaces, feathers, meltdown of dogs and cats, blood, brains and the spinal cords of cows, etc. is not permissible nor is it permissible to provide animals such feed. However, if the animals have been fed with such feed and that has been their staple diet, it will be permissible to consume the meat of such animals with the condition that the meat does not give off any bad odour.

It is not permissible to consume the meat of these animals if the meat gives off a bad odour. (Raddul Muhtaar vol.6 pg.340)

and Allah Ta'ala Knows Best

Mufti Ebrahim Desai