Egg storage has been a problem due to ineffective methods subjecting many farmers and egg retailers to losses. These techniques include various models involving statistical analysis of the storage conditions on the egg quality. Apparent deficiencies of the information from the randomized complete block design model prompted this study. The study evaluated the effect of storage temperature at three levels (5 ° C, 19.5 ° C, 30 ° C) and duration at four levels (2 nd , 12 th , 22 nd , 32 nd ) on egg quality using a fixed and mixed-effect model. We used a total of 618 fresh and unfertilized eggs from ISA (Institut de Sélection Animale) brown layers. We determined egg quality by the changes of physical characterization under storage conditions. The study used Restricted maximum likelihood and analysis of variance methods to assess the efficiency of fixed and mixed effect models. Results showed that the physical components of the egg were significantly affected at 5 ° C, 19.5 ° C, and 30 ° C . The effect was more adverse on eggs stored at 30 ° C for 32 days. However, storage temperatures of 5 ° C and 19.5 ° C led to an extensive reduction in the Haugh unit, yolk index, and egg white height. On the other hand, it increased the weight loss and albumen diameter under storage for 2 nd , 12 th , 22 nd and 32 nd -time intervals. Based on these findings, the study recommends 5 ° C for egg quality preservation. The eggs should be refrigerated for 32 days, stored at 19.5 ° C for 14 days, and lastly kept at 30 ° C for a maximum of 7 days. The fixed-effect models exhibited more minor variances in diameter and height of albumen, yolk index, weight loss, and Haugh unit. This overlapped instances where the fixed-effect models were significantly the same as the mixed-effect models. This study proposes that the fixed effect model is the most appropriate for randomized completely block design experiments.
Keywords: Chicken egg; Experimental design; Fixed model; Mixed model; Variance component.
© 2021 The Author(s).