Quality of Eggs Under Varying Storage Periods, Conditions and Seasons in a Semi Arid Zone of Nigeria

Abstract

This study investigated the effects of storage time, season and egg weight on external and internal characteristics of chicken eggs. Two hundred and forty (240) eggs of small(51.42 g ± 0.26), medium (56.05 g ± 0.26) and large (61.01 g ± 0.29) grades were collected from the battery cage laying chickens and stored at room temperatures of 40EC and 31EC during the dry hot and wet seasons respectively. The corresponding averages for relative humidity were 29.38% and 65.39%. Ten (10) eggs from each of the three weight groups were examined as soon as they were collected and subsequently, 4, 8 and 12 days after storage; making a total of 120 eggs per season. The eggs were analyzed for their weight, length, width, albumen length, albumen width, albumen height, yolk length, yolk width, yolk height, shell weight, shell thickness, shape index, albumen index, yolk index and haugh unit. There was a significant effect (p<0.01) of egg weight on egg width, egg length, shell weight, shape index, albumen length, albumen width and albumen index. All the egg quality factors were significantly (p<0.001) affected by storage period except egg length, egg width, shape index and shell thickness. Albumen length, albumen width, yolk length, yolk width increased with increase in storage period, while albumen length and yolk height decreased with increase in storage period. Storage time did not affect (p>0.05) shell weight, shape index, egg length and egg width. The effect of season was significant (p<0.001) on all the egg quality factors (with effects been pronounced during dry season) except shell weight and shell thickness. The interaction effects showed that large eggs were more affected by storage period than small eggs while, seasonal effect became more pronounced with prolong storage period.

Key words: Egg, quality, season, storage