A comparison of meat composition, tenderness and the fatty acid profile of three muscles from Holstein-Friesian bulls from production system resulting in final ages of either <16 or 19 months

Context: The increased number of male dairy origin calves in Ireland due to the abolition of European Union milk quotas is a potential resource for the beef industry. Rearing these animals as bulls rather than steers is more efficient from a production perspective. Ensuring satisfactory quality of bull beef from dairy origin is essential. Aim: To determine the effect of two production systems and three muscle types on physico-chemical characteristics and fatty acid (FA) profile of beef from Holstein-Friesian (HF) bulls. Methods: Thirty HF bulls were equally assigned to two production systems, namely, slaughter at under 16 months of age or slaughter at 19 months of age. Longissimus thoracis (LT), Semitendinosus (ST) and Gluteus medius (GM) muscles were excised post-slaughter for determination of pH, colour, Warner-Bratzler (WB) variables, cook loss, chemical composition [intramuscular fat (IMF), moisture, protein, ash], collagen characteristics and FA profile. Results: WB variables and cook loss after 14 days postmortem ageing, and insoluble and total collagen contents were higher, while IMF content, redness and saturation at 24 h post-blooming were lower for muscles from the 19-month production system. Muscles from the under 16-month production system had a higher saturated fatty acid (SFA) proportion and n-6:n-3 polyunsaturated fatty acid (PUFA) ratio, while muscle from the 19-month production system had a higher PUFA proportion, n-3 PUFA proportion and PUFA:SFA ratio. The GM muscle had the lowest L∗ value, followed by LT and ST. Yellowness, saturation and hue angle were greater in ST. LT had lower WB variables, cook loss, moisture, and a higher IMF content than ST and GM. The PUFA proportion and PUFA:SFA ratio were highest in ST, followed by GM and LT. IMF, total FA, SFA and monounsaturated fatty acid (MUFA) concentrations were higher in LT from the under 16-month production system bulls (the interaction). Conclusions: Beef from the under 16-month production system compared with beef from the 19-month production system, and LT compared with ST and GM muscles had better quality characteristics. Implications: Dairy bulls can produce beef of acceptable quality. The findings will guide selection of the combination of production system and muscle type most appropriate to specific market requirements.