questions: asking about fish feed supplement in fish grow out farming  
 answers: suggestion 
instead of mustard oil cake you can use ground nut oil cake with rice bran 
apply rice bran and ground nut oil cake @ 1:1 ratio as i told you earlier
supplementary feed include floating feed which is for grass carp, catla, rohu, big head 
and sinking feed for common carp and mirgal
buy supplementary feed containing 24 % protein content 
some of the feed company are godrej, abis, nsf
in winter time please reduce the feed quantity