Drilling down into impact of stress on beef eating quality

Cattle from eight farms in Tasmania, including four from King Island, have been studied to determine the effect of both on-farm and marketing practices on their eating quality as determined by the Meat Standards Australia program.

Each farm has supplied 60 head, some consigning just steers and others heifers.

Boat transport from King Island, along with saleyard versus direct pathways have been investigated.

Cattle from all farms were allocated to treatments of never mixed, mixed with the same sex from another property and mixed sex and property.

All were assessed three weeks prior to travel with measures including weight, crush score, thermal mapping in the lead-up to crush and in the crush prior and post eartagging, retinal scanning and flight speed on exit.

Pasture samples were also collected for analysis from each property.

On arrival at abattoirs, some cattle were transferred to paddocks for two weeks of grazing and others processed immediately.

Measurements were repeated, plus blood samples taken, while pH declines were measured on carcases.

All cattle were MSA graded and also assessed with camera technology prior to boning, where striploins, tenderloins, outsides and oyster blades were collected.

The King Island samples went to the University of New England in Armidale where they were fabricated into consumer samples.

All cuts had a standard seven and 21 day ageing treatment.

The direct-to-abattoir and saleyards pathways product went to the Gold Coast where cuts were exported to Japan, vac packed and frozen.

Close to 8000 samples are now being tested by consumers here and overseas.

MSA program manager Sarah Strachan said the impact of stress on eating quality had been a long-term concern, allied with welfare considerations.

MSA had applied a series of risk minimisation pre-conditions for grading including not mixing cattle, direct consignment to slaughter and time from farm to slaughter, Ms Strachan said.

“These are general best practice but it is known there are considerable variations which aren’t able to be individually and objectively assessed in the live animal,” she said.

“A further consequence is that traditional selling practices such as saleyards and long distance trucking beyond the current MSA requirements, have rendered cattle ineligible.”

A big part of this work has been with the objective of being able to grade all cattle MSA in mind, she said.

Preliminary results have shown large individual animal variance within all treatment groups.

Ms Strachan said that further emphasised the importance of an effective individual animal indicator, as well as the critical nature of on-property management in relation to pH outcomes and subsequent eating quality.

For father and son Les and Troy Porteus, who run one of Tasmania’s largest cattle fattening operations “Thousand Acre Plains” at Smithton, tweaking management practices to improve MSA compliance is continual.

“We want to know about anything and everything that can be done to improve the quality of what we turn off,” Troy Porteus said.

“Anything that doesn’t grade holds back our prices.”

Porteus cattle actually have a very high MSA compliance - around 97 per cent - but given dark cutting is their biggest mark down, the producers see great value in this research and that is why they agreed to take part in the trials.

Their 1600 hectares of mainly renovated pastures over three farms turns off 1500 to 2000 mostly steers a year of mostly British-bred cattle.

They buy in at 300-400 kilograms and taken them to 700kg in under 12 months.

Cattle are sold direct with most supplying the Cape Grim brand.