10:30 〜 10:40
[VII-20-10] Breed and sex comparative analyses of chicken skeletal muscle collagen content, COL1A1 expression and histological properties
With Intramuscular collagen (IMC) having a significant impact on muscle toughness hence affecting overall tenderness of meat, this study compared total collagen contents, COL1A1 expression levels, and histological properties of Musculus iliotibialis lateralis (ITL) and Musculus pectoralis (PT) of 10 weeks old male and female Rhode Island Red (RIR), Ross 308 (Ross), and White Leghorn (WLH). Ross had the highest body and muscle weights, but a breed difference in the percentage muscle to live body weight was observed only in the PT muscles. Higher total collagen content and COL1A1 expression levels were observed in the ITL muscles of WLH with more compact primary fasciculi, branched and thicker perimysium, and smaller myofibers than other breeds. Collagen content varied by sex only in the ITL muscles of WLH and PT muscles of RIR. The results suggest that variations in IMC content associated with COL1A1 expression levels, sizes of primary fasciculi and myofibers, and perimysium thickness contribute to variations in meat tenderness between chicken breeds that may not be noticeable between sexes until the chickens are more than 10 weeks old.