Hormonal Growth Promotant (HGP) use in the Australian Beef Industry

Summary

Hormonal growth promotants for cattle have been registered for use in Australia for the last 30 years. Growth rates of HGP treated cattle are increased in the range of 10-30 % and feed conversion efficiencies are improved by 5-15 %. The hormones are both oestrogenic and androgenic in the form of naturally occurring oestradiol and testosterone and the xenobiotics zeranol and trenbolone acetate. 
Implants are formulated to contain oestrogenic compounds alone or a combination of an oestrogen and an androgen, either testosterone or trenbolone acetate. Implants are used in both the grass-fed and feedlot sectors; the total number used in Australia in 2006/07 was 6.5 million. Their principal use in the grass-fed industry is to increase the rate of liveweight gain and produce heavier carcasses suitable for the liveweight and age specifications for high-value markets. Their main benefit in the feedlot industry results from an increased efficiency of feed conversion and the associated reduction in feed costs per unit of liveweight gain. An economic evaluation of HGP use in Australia conducted in conjunction with this scientific review estimated that HGP usage contributed an additional $210 million to the Australian beef industry in 2006-07.