# Genetic Parameters of Egg Quality Traits and Albumen Density in White Leghorn Chickens

## TL;DR

This study explores using albumen density as a low-cost indicator to estimate egg protein content in White Leghorn chickens.

## Contribution

The study introduces albumen density as a potential low-cost alternative to the Kjeldahl method for estimating egg albumen protein content.

## Key findings

- Albumen density (AD) showed strong positive correlations with albumen protein content.
- AD has potential as a supplementary tool for selecting albumen protein traits in breeding.
- Heritability of AD was low, but genetic correlations with egg weight and other traits were significant.

## Abstract

In practical production, the traditional Kjeldahl method was not suitable for large-scale use to determine the protein content of eggs, which was a key issue. Therefore, our research aimed to seek an indicator that could be used to estimate the albumen protein content in different types of eggs. Our study measured the albumen weight (AW) and albumen volume (AV), and then calculated albumen density (AD). In addition, we accurately measured the average albumen protein quantity (AAP) and total albumen protein quantity (TAP) in one batch of eggs using the Kjeldahl method. The results showed highly significant positive correlations between AD, AAP, and TAP, indicating that we could use this indicator to estimate protein content.

The conventional method for detecting protein content in egg albumen is the Kjeldahl method, but this method cannot be applied in practical production due to cost limitations. Therefore, we developed albumen density (AD), which had certain potential application value in low-cost and efficient evaluation of albumen protein content. We calculated the heritability of AD in White Leghorn (WL) chickens and its correlation with average albumen protein quantity (AAP), total albumen protein quantity (TAP), albumen weight (AW), albumen volume (AV), egg weight (EW), albumen height (AH), haugh unit (HU), and yolk color (YC). It is worth noting that albumen protein content was measured in a small subset of samples. The average value of AD in eggs was 0.97 and its heritability was less than 0.1. The average value of AAP in eggs was 10.1%, and the average value of TAP in eggs was 2.95 g. There were significant positive correlations between AAP, TAP, AW, AV, AD, and EW, and there were strong positive genetic and phenotypic correlations between EW, AW, AV, and AD. The results of this study indicated that AD might have potential value as a supplementary tool for albumen protein trait selection in breeding.