Effect of Myostatin Gene Mutation on Slaughtering Performance and Meat Quality in Marchigiana Bulls

SIMPLE SUMMARY: The aim of this work was the evaluation of slaughtering performance in a sample of 78 Marchigiana bulls with different allelic situation at the myostatin locus; in addition, the qualitative composition of meat samples collected from Longissimus thoracis muscle was evaluated. At the myostatin gene, 67 homozygotes normal, 11 heterozygotes, and no double-muscled homozygote bulls were detected. Heterozygote bulls showed high values in final live weight and dressing yield; moreover, they were characterized by a low incidence of fat at steak dissection, as well as in meat chemical composition. A better muscular conformation in heterozygote bulls’ carcasses was highlighted, with a higher incidence of their carcasses in class E and evident convexity of round, back, and shoulder muscular masses compared to the carcasses of Marchigiana bulls which were normal at the myostatin gene. ABSTRACT: The myostatin gene also called Growth Differentiation Factor 8 gene (GDF8) is one of the most investigated loci that can be responsible for several quantitative and qualitative carcass and meat traits in double-muscled beef cattle. The objective of the study was to bring to light the effect of the myostatin polymorphism on slaughtering performance and meat quality in Marchigiana beef cattle. The experiment was carried out on 78 bulls reared according to the “cow-calf” extensive managing system. At the end of the fattening period, in vivo and carcass data were recorded. From each carcass, a steak of Longissimus thoracis was taken and used to determine the meat’s analytical composition and colorimetric properties. Finally, from each steak a sample of Longissimus thoracis was collected, then used for DNA extraction and genotyping at the myostatin locus. The heterozygous bulls showed slight superiority in the carcass data (e.g., hot carcass weight: 426.09 kg—heterozygotes vs. 405.32 kg—normal) and meat quality parameters, although not always with statistical significance. Only fat and ashes content were significantly affected by the myostatin genotype (heterozygotes: 2.01%, 1.26%; normal: 3.04%, 1.15%). The greater muscularity of heterozygous animals compared to normal ones could be a starting point to improving productive efficiency in Marchigiana beef cattle.