# Shaping Goose Meat Quality: The Role of Genotype and Soy-Free Diets
## 1 Introduction  
In recent years, the dynamic development of the poultry sector has been observed worldwide, resulting from the growing demand for poultry meat, including goose meat. Changing consumer preferences and increasing nutritional awareness have led to the search for production methods that not only improve meat quality but also make production more efficient and sustainable [1]. Geese are increasingly valued in Europe for their meat quality and sustainable production potential [2]. China is the largest producer of geese in the world, accounting for over 90% of global production [3]. In Europe, goose breeding is mainly concentrated in Poland, Hungary, and Germany. Poland holds a leading position among goose meat exporters, supplying high-quality products mainly to Western European markets. The breeding is dominated byhighly specialized breeds such as the White Kohuda Goose, characterized by a fast growth rate, good feed conversion efficiency, and high meat quality [2; 4]. One of the key elements in optimizing goose production is the use of crossbreeding methods to obtain the heterosis effect [5]. Appropriate genetic combinations can lead to improvements in the growth rate, feed conversion, and slaughter parameters, which translates into higher production efficiency [6; 7]. In this study, the [PERSON] (T) and [PERSON] (E) lines were used, which belong to German meat goose lines with high production potential. Crossbreeding these lines offers a possibility to improve meat traits and meet market demand for heavier carcasses [7]. In addition to the genetic aspects, feeding plays a key role in the quality of goose meat. In traditional feeding systems, the dominant source of protein is soybean meal; however, rising production costs and issues related to the ecological sustainability of breeding necessitate the search for alternatives [8]. Among them, yellow lupin (_Lupinus luteus_) is promising due to its high protein content, balanced amino acid profile, and reduced levels of antinutritional compounds [9; 10]. Feeding affects many meat quality indicators, such as fat content, fatty acid composition, water retention, pH, and sensory traits [11; 12]. Studies suggest that yellow lupin may enhance tenderness and water-holding capacity without compromising technological parameters such as cooking loss or meat colour [8; 13; 14]. Meat colour, water-holding capacity, and texture are important indicators of technological and sensory meat value, affecting consumer acceptance [14]. The goose muscle colour parameters (L*--lightness, a*--redness, b*--yellowness) are influenced by both genotype and diet, although studies show that genotype has a more dominant effect [14]. Water-holding capacity, assessed via cooking loss, is another key indicator. Lupin feeding has been associated with reduced thermal losses and better juiciness. These effects may result from differences in the muscle protein structure and pH-dependent protein hydration [7; 15; 16]. Higher pH values after slaughter tend to improve meat colour and tenderness, while rapid postmortem pH decline can impair water retention and texture [17]. The role of the genotype is also reflected in the muscle structure and composition. Local goose breeds often show smaller muscle fibre diameter and higher protein content, contributing to greater tenderness compared to commercial lines [18]. Differences in the intramuscular fat and collagen content have also been shown to affect meat quality between traditional and intensive genotypes, such as Zatorska and White Koluda geese [18]. [PERSON] et al. [19] reported that replacing soybean with lupin in goose diets did not negatively affect breast muscle tenderness but improved the water-holding capacity, which influences perceived juiciness. Texture perception is multifactorial and depends on muscle mechanics, shape, moisture, and fat levels--all contributing to the sensory impression during chewing [20]. Texture is another critical quality attribute. It is often measured via shear force or texture profile analysis.