102. Sensory characteristics of muscle from Angus-sired suckler bulls finished at pasture, with or without concentrate supplementation, at 15 or 19 months of age

Application: If the sale of beef cattle was not limited by a carcass fatness specification, lower-cost pasture-based suckler bull finishing systems could be a viable option on many beef farms. Introduction: Suckler bull beef production usually involves a post-weaning indoor feeding period based on conserved forage supplemented with concentrates or concentrates offered ad libitum. In temperate climates, finishing cattle from pasture decreases the cost of production. Carcass fat classification is an important determinant of carcass acceptability by meat processors in the Republic of Ireland, based in part, on a perceived association with meat eating quality. Lenehan et al. (2017) reported that carcasses of spring-born Angus-sired suckler bulls were adequately finished (fat score ≥6.0, scale 1-15) from pasture, with or without concentrates at 19, but not at 15 months of age. Slaughter at a younger age reduces the environmental footprint of beef production (Herron et al., 2021). The objective of this study was to determine if these differences in age and fat classification were reflected in the sensory characteristics of the meat. Materials and methods: Sixty Spring-born Aberdeen Angus-sired ‘weanling’ bulls were assigned to a two (slaughter age, 15 or 19 months) by two supplements (0 or 3.2 kg dry matter of a barley-based concentrate daily) factorial arrangement and turned out to pasture on 7 April. Concentrates were introduced immediately post-turnout for 15-month bulls and 97 days later for 19-month, bulls. The 15- and 19-month bulls were slaughtered 63 and 193 days post-turnout, respectively, and the longissimus thoracis muscle collected (Lenehan et al., 2017). Sensory testing of 14 day aged meat was conducted using untrained assessors who rated, on an 8-point hedonic scale, tenderness, overall flavour, overall firmness, overall texture and overall acceptability (Moran et al., 2021) (Table 1). Data were analysed using the REML procedure of Genstat (16th edition). Breed maturity, concentrate supplementation, their interactions and block (weight) were considered fixed effects, and the interaction of assessor, breed maturity and concentrate supplementation a random effect. Results: Despite the 15-month bulls not achieving the fat classification currently required (6.0, scale 1-15 on the EUROP carcass classification grid), there was no difference in overall acceptability of the meat (Table 1). Conclusion: Carcass fat score is a poor indicator of meat eating quality of meat from suckler bulls. The current market specification of a minimum carcass fat score, if based on meat eating quality, is not justified.