The effect of sex on meat quality and the fatty acid profile of the longissimus lumborum muscle in growing-finishing pigs

The aim of this study was to evaluate the effect of sex on meat quality and fatty acid (FA) composition in growing-finishing pigs. Meat samples were collected from gilts, surgically castrated males and immunocastrated males. Surgical castration was carried out at 5 days of age, whereas immunocastration was performed with two injections of Improvac administered 4 weeks apart, at 9 and 15 weeks of age. Pigs were fed complete diets containing 17% and 15% of total protein, respectively Pig Nutrient Requirement. Feed and water were available ad libitum. Pigs from each group were kept in separate pens, and they were slaughtered at BW of around 105 kg. The pigs were slaughtered according to the usual procedure in meat plants. Samples of the longissimus lumborum muscle (musculus longissimus lumborum, LL), approximately 10 cm thick, were collected from the right half-carcasses to determine the proximate chemical composition, physicochemical properties and sensory attributes of meat. The content of dry matter, total protein (Kjeldahl method), crude fat (Soxhlet extraction) and crude ash, and the FA profile of meat samples were determined. Fatty acids were separated by gas chromatography. Fatty acid methyl esters (FAMEs) were prepared according to the modified Peisker method. Fatty acids were identified by comparing their retention times with those of pure FAME standards (Sigma-Aldrich, St. Louis, Missouri, USA) and peaks in the analyzed samples. The relative content of FAs was expressed as the percentage of the total surface area of all FAs detected in each sample. Sex had no influence on the quality or processing suitability of pork, but it affected the intramuscular content, which is an important consideration for consumers.