The impact of two different hormonal growth promotants (HGPs) on the eating quality of feedlot finished steers - David Packer

Tuesday 25th October 2016.

The Meat Standards Australia (MSA) beef grading model predicts the eating quality outcome of different cuts by cooking method from commercial inputs of on-farm, carcass traits and processing inputs. Based on a body of Australian research in the mid-2000’s it was demonstrated that Hormonal Growth Promotants (HGPs) have undoubtedly a negative impact on beef eating quality over and above an effect on maturity (ossification) and fat content, in the order of three to six palatability points (MQ4). Subsequently, an adjustment of approximately four to five MSA index points is applied to any carcase that is presented for grading whereby the animal was treated with a HGP.

Since the introduction of the HGP adjustment, some industry stakeholders argued that the research conducted to establish the magnitude of the HGP adjustment did not allow for the hypothesised variable effects of different HGPs used in Australia. This was because, in the majority of the studies conducted, animals received multiple implants and/or were finished with a combination trenbolone acetate and oestradiol HGP implant. This made individual implant contribution to eating quality effects, difficult to distinguish, and therefore, to protect the consumer, the MSA pathways committee decided on one collective HGP adjustment.

This seminar will present findings from a trial which compared the meat from steers finished in a feedlot with three HGP treatment groups; Control (no implant), oestradiol only implant (21.1 mg oestradiol-17ß) or combination oestradiol and trenbolone acetate implant (200mg trenbolone acetate and 20mg oestradiol). Samples from these animals were tasted by untrained consumers for tenderness, juiciness, flavour and overall liking as a measurement of eating quality. Further laboratory meat quality assessments were conducted as supporting data. Results indicate these HGP implants have different impacts on eating quality measurements.