Effects of storage time and hot weather conditions on egg qualities of two avian species

The present study was conducted to determine the external and internal egg quality of Isa Brown (Gallus gallus domesticus) chicken and Japanese quails (Coturnix coturnix japonica) as affected by storage time under room temperature in the hot weather conditions of Nigeria. Parameters evaluated included egg weight, albumen and yolk indices. For each species, a total number of twenty freshly laid eggs was collected and divided into five groups representing different days of storage (0, 7, 14, 21 and 28 days). Storage temperature and relative humidity respectively, are 28.3ºC and 75%. Analyzed results showed that storage time significantly affected egg weight, but has no effect on egg length and width in the two species. Egg weight at day 0 and 7 were higher and superior to 14, 21 and 28 days. Shell thickness in this study had significant decrease in values from day 0 to 28. The decline in this trait due to prolonged storage time was probably due to loss of water as a result of evaporation from internal egg which caused loss of viscosity. With regard to albumen indices, there was a decrease in the values of albumen weight and others with increasing age of eggs in store. Pertaining to internal egg quality, Haugh unit score which measures the freshness and quality of an egg equally recorded a gradual decline from day 0 to 14, while the values fell below standard from day 14. This implies that chicken and quail eggs are not fit for human consumption after 14 days in the hot environment unless stored in refrigerator. Yolk indices such as yolk width and height decreased with advancing age of eggs in the store. But the reverse was the case for yolk weight and ratio which recorded higher values as storage time progressed. As indicated in this study, chicken and quail eggs should not be held under room temperature for more than 14 days during hot season to maintain its freshness and quality.