Effect of repeated implants of oestradiol-17β on beef palatability in Brahman and Braham cross steers finished to different market end points

Abstract

The effect of repeated implantation with 20 mg oestradiol-17β (Compudose 100) on carcass and meat quality traits was investigated using 478 'Bos indicus' and 'B. indicus' × 'Bos taurus' cross steers finished on either pasture or grain to achieve carcass weight for one of three market end points (domestic, 220 kg; Korean, 280 kg; or Japanese, 340 kg). In the oestradiol-17β treatment group, animals were administered implants at ~100-day intervals, with the number of implants administered to any steer ranging from one to eight. Cattle were slaughtered and at boning the anterior portion of the 'M. longissimus lumborum' was removed and frozen after aging for 1 day for later objective meat quality measurements (shear force, compression and cook loss %). The adjoining portion was aged for 14 days before consumer sensory testing using the Meat Standards Australia protocols. Each sample was scored for tenderness, juiciness, like flavour and overall liking by 10 untrained consumers. Implanting increased carcass weights and ossification scores (P < 0.05) and reduced marbling scores in comparison to non-implanted carcasses. For tenderness, like flavour, overall liking and MQ4 scores there was a significant (P < 0.05) interaction between 'B. indicus' content and oestradiol-17β treatment, whereby high 'B. indicus' content cattle that were implanted with oestradiol-17β had the lowest sensory scores. The number of implants administered did not affect carcass weights or marbling scores, whereas ossification scores increased in carcasses as the number of implants increased. The number of implants administered had no effect (P > 0.05) on sensory scores, or objective meat tenderness.