# Analysis of Carcass and Meat Characteristics in Breast Muscle Between Hubbard White Broilers and Xueshan Chickens

## TL;DR

This study compares meat and carcass traits in two chicken breeds, finding that commercial broilers have higher yields but lower meat quality than native chickens.

## Contribution

The study identifies breed-specific differences in muscle biology and fatty acid composition affecting meat quality and production efficiency.

## Key findings

- Hubbard White broilers have larger carcasses and breast muscles but lower meat quality compared to Xueshan chickens.
- Xueshan chickens show higher redness, yellowness, and PUFA content, suggesting better flavor potential.
- Xueshan chickens have lower mRNA expression for lipid metabolism genes like Fabp4 and Pparα compared to Hubbard White broilers.

## Abstract

The comparative analysis reveals fundamental differences in muscle biology between commercial and native chicken breeds. While intensive selection in HW enhances growth efficiency and muscle hypertrophy, it concurrently reduces meat quality through an altered fiber architecture and lipid composition. The elevated PUFA content (particularly n-3 fatty acids) in XS suggests greater potential for flavor compound formation during cooking. The distinct post-mortem biochemical profiles, evidenced by differential pH decline rates and protein degradation patterns, indicate breed-specific muscle-to-meat conversion processes. These findings provide actionable insights for developing breeding strategies that balance production efficiency with meat quality preservation.

The focus on selecting broilers for rapid growth rates and enhanced breast muscle yield has resulted in a decline in meat quality. The differences in carcass characteristics and meat quality between Hubbard white broilers (HWs, a commercial breed) and Xueshan chickens (XSs, an indigenous breed) at market age were analyzed to determine the potential mechanisms responsible for these differences. The results show that HWs exhibited significantly better carcass performance than XSs, including the larger weight of the carcass, the breast muscle, and the thigh muscle (p < 0.01). In addition, based on HE staining analysis, HWs’ breast muscles had a considerably larger average myofiber area and diameter than those of XSs (p < 0.01). Furthermore, the physical characteristics of the meat revealed that XSs had higher redness and yellowness and also higher lightness. HW meat had a higher pH and thermal loss, but a lower shear force and drip loss than XS meat (p < 0.01). The content of saturated fatty acids (SFAs) and polyunsaturated fatty acids (PUFAs) was, remarkably, lower in the breast muscles of HWs than of XSs (p < 0.01). In contrast, HWs had a larger concentration of monounsaturated fatty acids (MUFAs) than XSs (p < 0.01). Finally, the breast muscles of XSs had lower levels of mRNA expression for genes linked to lipid metabolism, such as fatty acid binding protein 4 (Fabp4) and peroxisome proliferator-activated receptor alpha (Pparα), and had higher levels of the phosphofructokinase muscle type (Pfkm) compared to HWs (p < 0.01). These results indicate that a lower carcass yield was observed in XSs compared with HWs, but that XSs showed better performance in terms of meat quality than HW.