Physical and sensory characteristics of hindquarter muscles of young Holstein, Brahman and Charbray bulls grown under grazing

Abstract

Twenty-seven bulls (10 Holstein, nine Charbray and eight Brahman) grown under grazing conditions were harvested at 31 to 35 months (598 kg) to study the effect of breed and muscle upon sensory characteristics of tenderness, juiciness and overall acceptance. Hindquarter samples from the psoas major (PM), semimembranosus (SM), semitendinosus (ST), longissimus dorsi (LD), rectus femoris (RF), gluteus medius (GM), and biceps femoris (BF) muscles were taken after a 24-h aging period. Shear force, sensory panel, and intramuscular fat (IF) analyses were performed. Beef quality characteristics were not significantly affected (P > 0.05) by breed, and were considered acceptable in tenderness as determined by Warner-Braztler (WBS) and Texture Analyzer (TA.XT2) shear force, and slightly tender, juicy, and acceptable by sensory evaluation. The seven hindquarter muscles of Brahman bulls had a higher (P < 0.05) content of intramuscular fat (1.2%) than those of Holstein (0.8%) and Charbray (0.9%). The PM was the most tender hindquarter muscle by WBS, TA.XT2, and sensory evaluation and the most juicy and acceptable (P < 0.05). According to WBS, ST was more tender than SM, LD, and BF (P < 0.05). At the same time, GM and RF were more tender than LD and BF (P < 0.05). Conversely, TA.XT2 determined that SM was similar in tenderness to BF (P > 0.05) but tougher than the other muscles (P < 0.05). Strategies to reduce the slaughter age of cattle grown under grazing and a better understanding of the mechanisms associated with the deposition of intramuscular fat might result in a greater palatability of the locally produced beef.