author(s)
Avnish Kumar Gautam, Sanjay Ray, Partha Das, Arun Kumar Mandal, Nirmal Kumar Tudu, Dharmendra Singh and Moffijul Islam

abstract
A study was conducted on the seventy (70) day old broiler chicks which were reared up to 42 days (market age) of post hatch period. The whole experimental period of study was divided into seven (07) groups, each containing ten (10) birds irrespective of sex accordingly. The cerebrum was the largest part of brain and triangular to oval in outline. The length of cerebrum was varied from 9.19 mm to 16.07 mm with mean value of 9.38±0.04 mm to 15.07±0.13 mm from group I to group VII. The Width of the whole cerebrum ranged between 14.04 mm to 20.14 mm with value of 14.18±0.21 mm to 19.70±0.1 from group I to group VII. A highly significant difference was observed in the length as well as width in Group I to group VII with the advancement post hatch period.