Developmental Morphometry of the Body and Brain in Wild Spotted Helmeted Guinea Fowl: A Pre and Post-Hatch Study

Abstract

There are dearth of information on the developmental index of the body and brain of study in this wild species of avian in Nigeria. This work was aimed at providing baseline developmental indices in the body and brain of wild helmeted guinea fowl at pre- and post-hatch periods. Two hundred and ninety-four (294) fertilized eggs of wild helmeted guinea fowl were used for the study.  Out of the total number, 196 egg were used for pre-hatch and 96 eggs were used for post-hatch studies. Eggs were purchased from National Veterinary Research Institute (NVRI) Vom and local breeders within Jos town and its environs. At pre-hatch period, the mean weight of the whole embryo of the helmeted guinea fowl on day 4 of incubation was observed to be 0.040 ± 0.0021 g. On days 13, 19, 23 and 28, their mean weights were 1.951 ± 0.08 g, 7.080 ± 0.809g, 12.592 ± 1.305 g and 18.687 ± 1.647 g, respectively. The mean weight of the cerebellum on day 11 of incubation was 0.0038 ± 0.001 g. On day 23 pre-hatch, the mean weight was observed to be 0.0103 ± 0.001 g. The mean length of the whole brain of the helmeted guinea fowl on day 4 of incubation was 0.2074 ± 0.0232 cm. On days 10, 18, 22 and 26, the mean weights were 1.1180 ± 0.0041 cm, 1.4643 ± 0.0587 cm, 1.5191 ± 0.0596 cm and 1.6404 ± 0.0401 cm, respectively. At post-hatch morphometric studies, the mean weight of the helmeted guinea fowl keets at day 1 was 20.353 ± 1.1946 g. At days 10, 28, 37 and 55, the mean weights were 30.089 ± 2.4275 g, 51.0443 ± 5.1568 g, 109.062 ± 4.5119 g and 244.401 ± 26.2049 g, respectively.  Brain weight increased proportionally with body weight, though it remained consistently lower