Abstract

This study was carried out to investigate the development of the midbrain in the grey breasted helmeted guinea fowl. Domestication of grey helmeted guinea fowl is increase but scanty documentation on the development of midbrain (mesencephalon) and how it relates to the neurobiology of this bird is lacking. A total of sixty six (66) fertilized guinea fowl eggs were purchased from National Veterinary Research Institute (NVRI) Vom, Jos, Plateau state, Nigeria and used for this study. Grossly, in the wild grey breasted helmeted guinea fowl, theopticlobe develops following development of midbrain and the midbrain appeared first on day 10 of incubation flank by the optic lobes on each sides. There was steady increase in the weights of the midbrain up to day 28 of incubation. This was expressed graphically at pre-hatch period which went up at day 17 and dropped at day 20 of incubation. Significant increases (P ≤ 0.0001) of the midbrain were seen on days 23 and 26. This indicates that as body and brain weights were increasing, there was a concurrent increase in midbrain weight. Morphologically, the midbrain was fully developed at pre-hatch period. This indicates that contribution from optic lobe to auditory-visual systems is fully developed in the wild grey breasted helmeted guinea fowl immediately after hatching and is capable of surviving independently.

Keywords: Grey,  Helmeted,  Midbrain, Morphogenesis,  Pre-hatch