A Method to Reduce the Occurrence of Egg Translucency and Its Effect on Bacterial Invasion

Abstract

Translucent egg consumption is low due to consumer acceptance and quality concerns, which is a problem that egg producers need to address. This study was performed to evaluate the reasons for the high occurrence of egg translucency in summer, as well as whether the addition of mono-dicalcium phosphate (MDCP) to the diet can relieve eggshell translucency and whether eggshell translucency is associated with the risk of bacterial invasion. A total of 72 laying hens that were 36 weeks old were randomly divided into control (CON) and MDCP groups and fed in the same environment. Results showed that the number of translucent eggs increases in July and August as the temperature and humidity increase. Compared with the CON group, in July, August, and October, the translucent egg grade (TEG) of the MDCP group was lower than that of the CON group (p < 0.05). TEG was correlated with mastoid space height (MSH), width (MSW), and area (MSA) (correlation coefficients 0.63, 0.59, and 0.68, respectively, p ≤ 0.05). There was no significant difference in the invasion rate of E. coli between translucent and non-translucent egg groups (47.2% vs. 39.33%), and translucent area and non-translucent area (13.49% vs. 15.08%). In conclusion, our results show that dietary MDCP may alleviate eggshell translucency and that eggshell translucency would not increase the probability of E. coli cross-shell penetration rate.

Research Note: Three-dimensional microstructural basis for chicken eggshell translucency

“…No significant differences were found between the T H and T L groups, which align with previous research, where no significant differences in the mastoid space area were observed among the various eggshell translucency groups ( P < 0.01). Additionally, eggshell membrane thickness in the T H group was significantly higher than that in the T L group ( P < 0.01), consistent with prior studies ( Shi et al, 2023 ). Interestingly, when examining the X-ray image samples, it was noted that in the T H group, many mastoid cores were located on the inner side of the eggshell membrane (i.e., within the internal region of the egg).…”

“…Previous studies have employed SEM to observe the microstructure of eggshells. Each SEM image sample is typically around 500 μm in size, enabling accurate measurements of mastoid space height and width, thus providing a reliable microscopic foundation for understanding the formation of eggshell translucency ( Wang et al, 2017 ; Shi et al, 2023 ). However, the eggshell is a 3-dimensional entity, constituted by a complex interplay of spatial dimensions.…”

“…Moreover, it is well established that factors, such as the breed and age of the laying hen, as well as dietary composition and environmental conditions, influence eggshell translucency ( Talbot and Tyler, 1974 ). Additionally, laying hens experiencing thermal stress exhibit changes in eggshell microstructure, thereby augmenting the occurrence of translucent eggs ( Shi et al, 2023 ).…”

Translucent eggs of laying hens: a review

“…Then, three evaluators compare the eggs to these standard images. An egg is classified as having a particular level of translucency when two evaluators provide a consistent evaluation level ( Shi et al, 2023 ). The grading standards for manual evaluation methods vary ( Figure 1 ), ranging from level 3 to level 6, and there is no unified classification ( Holst et al, 1932 ; Chousalkar et al, 2010 ; Wang et al, 2019 ; Shi et al, 2023 ).…”

“…However, pink eggs often have eggshell translucency, which reduces their overall appearance quality ( Zhang et al, 2021 ). As a result, the decrease in egg quality leads to a decrease in consumers’ purchasing intention and significant economic losses for the egg production industry ( Shi et al, 2023 ).…”