An unconventional feedstuff with great future prospects has been discovered for animal production. This study investigated the physical characteristics, nutritional and anti-nutritional composition of the kernels of ten (10) different mango cultivars namely: Alphonso, Indesina, Julie, Kent, Mabranka, Magadugu, Peach, Peter, Taymour and Oori (A Nigerian local cultivar's commonly referred to as “Ogbomoso mango”). Mango kernels possessed a package of nutrients that can be used for livestock production. Solid state fermentation using mango kernel mycoflora lead to reduction of inherent anti-nutrients of 'Oori' mango kernel cake (MKC). Chickens fed diets supplemented with fermented MKC had enhanced feed intake, feed conversion ratio, improved nutrients bioavailability and growth performance over chickens fed unfermented MKC based diet. From the results of the bird’s performance, haematological, serum biochemical and histological analysis, in addition to the evaluation of the broilers carcass quality attributes, up to 60% of the Aspergillus niger and Penicillium chrysogenum (mixed)fermented MKC replacement for maize (27% inclusion) is suitable in broilers diet without deleterious effect.