Sustained growth promotion, carcass characteristics, and meat quality of steers treated with oestradiol-17b

Abstract

The experiment measured the effect of 2 hormonal growth promotion strategies on growth rate, carcass characteristics, and some objective measurements of meat quality of steers. Bos indicus × Bos taurus crossbred steers grazing improved tropical pastures were divided into 3 treatment groups: unimplanted controls, implantation once with a long-acting formulation containing 45 mg oestradiol-17β (Compudose 400, Elanco Animal Health, West Ryde, NSW), implantation every 105 days with a shorter acting formulation containing 20 mg oestradiol-17β (Compudose 100) (4 implantations).

Over a 420-day experimental period, steers implanted several times with oestradiol gained significantly (P < 0.001) more weight (279 kg) than those implanted once (251 kg) and the controls (230 kg). Respective carcass weights were 270, 255, and 244 kg. At the same carcass weight, oestradiol treatment had no significant effect on beef yield or carcass fatness. Increased total beef yields from implanted steers were associated with increased carcass weight, rather than significant modification of carcass composition.

Treatment had no significant effect on any of the objective measures of meat quality studied, including ultimate pH, peak force, compression, and adhesion.