Effect of Four Fattening Systems on Quality of White Kołuda ^® Goose Products ^*

Abstract This study explored the impact of whole grain of oat, barley, wheat, and corn used in the final stage of fattening (14–16 week of age) on the properties of meat and liver of White Kołuda ® geese, and variations between the examined tissues. Two identical experiments were conducted to enhance the credibility of the results. Goose livers showed significantly higher protein content than leg muscles and fattening with oats increased protein content in breasts and livers. Each fattening method resulted in the sum of essential amino acids (ΣEAA) exceeding the WHO standard. Barley- and oat-based fattening yielded the most favorable results in terms of protein quality, often resulting in higher essential amino acid index (EAAI) values (161–179) compared to the other two groups (159–166). The White Kołuda ® goose livers boasted elevated levels of most elements and demonstrated significant richness in both iron (Fe) (337 mg/kg) and copper (Cu) (304 mg/kg), substantially surpassing daily requirements in a 100 g serving. The products from the oat-fed and barley-fed groups also exhibited elevated levels of several elements, while corn-based products typically displayed some of the lowest levels of most elements. The breast muscles displayed a darker color with a redder hue and less yellowness compared to the legs. Additionally, the leg muscles exhibited the darkest shade when fattened with corn and the yellowest hue when fattened with oats.