Effects of collection zones and storage on hatchability and survival of feral helmeted guineafowl (Numida meleagris galleata pallas) eggs
The desire to shore up the shortfall in protein supply, the increased awareness of the importance of cholesterol free animal protein, like guineafowl, and the need to conserve their wild genes, have necessitated studies on improved captive breeding of feral helmeted guineafowl. Hence, this study was aimed at determining the effects of ecological zones and storage systems on the guineafowl eggs. Guineafowl eggs (n=214), were collected from identified and monitored-nests within the Kainji Lake National Park (KLNP) and Old Oyo National Park (OONP). Out of 91 eggs collected from KLNP, 32 and 38 were stored at room temperature (RT-21-25°C) and refrigerator (RF-17-20°C), respectively for five days prior to incubation while 21 eggs were not stored (NS-27-29°C), and out of 123 collected from OONP, 70 and 19 were stored for five days prior to incubation at (RT-21-25°C) and (RF-17-20°C), respectively while 34 eggs were (NS- 27-29°C). Prior to incubation, eggs were weighed, the height and width were measured. The process was repeated after incubation for unhatched eggs. Candling was done three days before hatching at day 29 of egg incubation. Embryo status of unhatched eggs was determined by cracking the eggs. Descriptive and inferential statistics were used to analyse the data. The NS eggs from Kainji (7.60%) and Oyo (2.01%) had the lowest percentage shrinkage in weight across the three storage systems. The order was reversed in height with RF eggs from Kainji (0.96%) and Oyo (0.46%) having lowest. The least shrinkage in width of eggs from Oyo was recorded in the RF eggs (0.00%) and in NS (0.59%) from Kainji. Eggs candling showed that presumed fertile (opaque) was highest (69.10%) in NS eggs followed by RT (45.00%). There was no significant difference (p>0.05) between the hatchability of eggs from the two parks though hatchability (7.60%) of Kainji eggs was higher than those of Oyo (7.40%). Further check on fertilization after incubation showed that RT (37.50%) eggs from Kainji were fertilized but were unable to hatch alive so also was RF eggs (21.10%). The study showed that the eggs sizes vary with ecozones while size of the eggs and storage systems affects hatchability and survival of feral helmeted guineafowl eggs in captivity.
Keywords: Guineafowl; ecozones; storage systems; incubation; candling; hatchability