Yaikuula (wind-driven evaporative cooling) saves most guinea fowl eggs for hatching in the Sudano-Sahelian belt

Abstract

Guinea fowl meat and eggs are highly prized by consumers in the Sudan-Sahelian belt countries such as Burkina Faso and Niger. However, compared to chicken, guinea fowl stocks in these countries are low. One of the reasons for the low stock holdings is that guinea fowl in captivity are poor at being broody hens. They do not sit on their eggs for the hatching of their keets. This problem has been addressed using synchronized surrogate chicken hens for brooding. Many chicken hens are provided with dummy eggs until they begin to brood, at which time the dummy eggs are switched to fertile guinea fowl eggs. The challenge with this solution is storing the guinea fowl eggs at room or ambient temperatures until the surrogate brooders are ready. The high room temperatures during storage initiates pre-embryo development that results in hatching unhealthy keets. Refrigerated storage is not an option, as most smallholder farmers in rural settings do not have access to electricity. The purpose of this study was to address the storage problem by introducing wind-driven evaporative cooling (YaiKuula); “Yai” is a Swahili word for “egg.” YaiKuula lowers the storage temperature ~15oC below ambient temperature during the day. Viable guinea fowl eggs were stored using YaiKuula for 0-3, 4-7, and 8-14 days. Ambient temperature and refrigerated (8oC) storage were done in parallel as negative and positive controls, respectively. Twenty-four surrogate brooders with six eggs each were used to hatch the stored eggs. Early and late embryo mortality, in addition to healthy hatching were monitored. The Student’s t-test was used to compare results. The highest rate (p<0.05) of early embryonic mortality (65%) was obtained with refrigerated storage for 8-14 days versus 37 and 12%, respectively, for ambient and YaiKuula storage for the same length of time. The hatching rates of eggs from 0-3 days of storage showed no significant difference between the three storage methods. However, YaiKuula storage yielded significantly (p<0.05) higher hatching rates of 80% versus 37 and 22% from ambient and refrigeration storage at 8-14 days, respectively, and 84% versus 65 and 61% for ambient and refrigeration storage at 4-7 days, respectively. YaiKuula has the potential to increase the number of guinea fowl among smallholder poultry farmers for increased incomes/resilience and better nutrition. Key words: Numida meleagris, evaporative cooling, wind energy, Rakai chicken model