Uterine Metabolomic Analysis for the Regulation of Eggshell Calcification in Chickens

Abstract

Eggshell quality is economically important for table eggs and functionally indispensable for hatching eggs. During the formation of eggshell in the uterus, organic matrixes in uterine fluid can control and modify the formation of calcified eggshell. At present, there are limited studies focusing on the effect of uterine organic metabolites on eggshell quality. In this study, an LC-MS-based metabolomic technology was performed to identify the crucial uterine metabolites that differently presented in hens producing eggs with divergent eggshell quality (eggshell strength, thickness, and weight). More than 1000 metabolites were identified in uterine fluid, and six putative metabolites, including phosphatidylcholine, diacylglycerol, verapamil, risedronate, coproporphyrinogen III, and biliverdin, were screened to play crucial roles in eggshell calcification. Then, two trials for oral administration and in vitro calcite crystal growth were conducted to verify the effect of potential different metabolites on the eggshell quality. Verapamil has a temporary effect on decreasing eggshell strength and eggshell thickness. Coproporphyrinogen III could induce smaller calcite crystals to improve eggshell strength while biliverdin could modify crystal morphology by forming rougher faces and rounder edges to strengthen the eggshell. The present study gives us new insight to understand the role of uterine fluid matrixes in eggshell calcification.

Supplementing cholamine to diet lowers laying rate by promoting liver fat deposition and altering intestinal microflora in laying hens

“…Indeed, supplemented cholamine did not significantly change the thickness of the mucosal and muscular layers of the uterus. The uterus is the site of eggshell formation, mucosal cells are responsible for secreting the eggshell components, and changes in the structure and function of mucosal layer can affect eggshell quality ( Nii et al, 2018 ; Wang et al, 2021 ). Therefore, in this study, no significant effect of supplemented cholamine on the thickness of the mucosal layer is consistent with no significant change of egg quality.…”

Identification of crucial genes and metabolites regulating the eggshell brownness in chicken

“…However, the eggshell strength of DBS line eggs was significantly weaker than that of LBS line eggs, which may be attributed to the influence of eggshell pigment on the eggshell calcification process. Eggshell pigment primarily exists in a vertical crystal layer [ 27 , 28 ], and can change calcite crystal size and morphology, thus affecting eggshell quality [ 29 ]. Pigment particles stored in the shell gland epithelial cells achieve their maximum deposition rate at the end of eggshell calcification [ 9 ], which may impair the deposition of vertical crystal layers, resulting in reduced density and a looser structure, thus diminishing eggshell strength.…”

TMT-based quantitative proteomic analysis unveils uterine fluid difference in hens producing normal and pimpled eggs

“…Eggshell provides mechanical protection to egg contents while ensuring gas exchange and calcium for the developing embryo ( Hahn et al, 2017 ). Eggshell, an important indicator of egg quality, is closely monitored in the poultry industry to prevent financial losses from damage during transportation and storage ( Wang et al, 2021 ). Pimpled eggs ( PE ), however, are a defect characterized by the presence of extra-calcified granules on either end of the eggshell.…”