Characterization of Chicken Skin Yellowness and Exploration of Genes Involved in Skin Yellowness Deposition in Chicken

Abstract

Skin color is an important economic trait in meat-type chickens. A uniform bright skin color can increase the sales value of chicken. Chickens with bright yellow skin are more popular in China, especially in the broiler market of South China. However, the skin color of chickens can vary because of differences in breeds, diet, health, and individual genetics. To obtain greater insight into the genetic factors associated with the process of skin pigmentation in chickens, we used a colorimeter and high-resolution skin photographs to measure and analyze the skin color of chickens. By analyzing 534 chickens of the same breed, age, and feed condition, we found that the yellowness values of the chickens varied within this population. A significant positive correlation was found between the cloacal skin yellowness values before and after slaughter, and the cloacal skin yellowness value of live chickens was positively correlated with the overall body skin yellowness value. Additionally, chicken skin yellowness exhibited low heritability, ranging from 0.07 to 0.27. Through RNA sequencing, 882 genes were found to be differentially expressed between the skin with the highest and lowest yellowness values. Some of these differentially expressed genes may play an important role in yellow pigment deposition in chicken skin, which included TLR2B, IYD, SMOC1, ALDH1A3, CYP11A1, FHL2, TECRL, ACACB, TYR, PMEL, and GPR143. In addition, we found that the expression and variations of the BCO2 gene, which is referred to as the yellow skin gene, cannot be used to estimate the skin yellowness value of chickens in this population. These data will help to further our understanding of chicken skin yellowness and might contribute to the selection of specific chicken strains with consistent skin coloration.

Indigenous, Yellow-Feathered Chickens Body Measurements, Carcass Traits, and Meat Quality Depending on Marketable Age

“…However, they significantly impact industrially processed products. Wu et al [ 31 ] found that carcass characteristics of chickens were the most intuitive sensory indicators influencing the choice of consumers. The skin color, uniformity, and color consistency of poultry were important reference attributes for consumers to choose and buy.…”

“…In general, chickens on day 90 performed better than those on day 100 in terms of carcass characteristics, which can significantly affect the choice of consumers [ 31 ]. However, chickens on day 100 performed better in terms of slaughter performance with better carcass characteristics, as in the follicle density and spotted skin.…”

The Effect of Breed and Age on the Growth Performance, Carcass Traits and Metabolic Profile in Breast Muscle of Chinese Indigenous Chickens

“…Indigenous, yellow-feathered chicken breeds are mainly concentrated in south China, especially in Guangdong Province. Among which, Mahuang and Tuer chickens are representative of the local chickens from Guangdong Province, and they have different characteristics in appearance, size, plumage and edible quality [15]. Conventionally, chickens with old age are preferred by Chinese consumers when preparing boiled chicken meat or chicken broth as they believe aged chickens can provide more flavor and nutrition.…”

Meat quality and flavor compounds of soft-boiled chickens: effect of Chinese yellow-feathered chicken breed and slaughter age

“…This might be due to the difference in cooking yield such that 817 cross broiler chickens lost more meat moisture than Mahuang and Tuer chickens. On the other hand, the slaughter age with respect to the yellow-feathered chicken breed was still at a young age of 60 d, as Mahuang chickens were raised for 120 d on some local chicken farms in China ( Wu et al, 2021 ). In addition, the Tuer chicken breed at 75 d showed comparable hardness of chicken breast meat with 817 cross broilers, and the chewiness in both Mahuang and Tuer chicken breast and thigh meat at 75 d was significantly higher than that of 817 cross broilers.…”