Sheep jam opening tool (and plugging)

Summary

​Background

At present within the Australian Industry and Internationally beef oesophagus are sealed primarily by the following methods: rubber elastrator rings, plastic clips of various designs and hand tying. All these present methods require the rodding of animals, which involves the opening of the neck and separation of the oesophagus from the trachea.

Previous projects (prior to 2004) by Food Science Australia (FSA) and co-funded by MLA produced an internal oesophagus sealing system for beef cattle and a further developed scaled down version to suit sheep. The systems used a “plastic plug and ring” arrangement combined with a vacuum system to seal the oesophagi of beef and sheep. As with the beef sealing, the sheep sealing system provided an improved method of oesophagus sealing without the risk of contamination associated with entering the body through the dirty hide/pelt.

The internal oesophagus sealing system also reduced contamination as a result of leakage from the oesophagus. The plug was applied immediately after stunning and prior to the throat being cut. Existing oesophagus sealing methods required the throat to be cut before occlusion takes place, with a risk of leakage occurring during this interval. Correctly applied oesophagus plugs provided an effective seal. There is a zero tolerance on contamination from paunch contents, and the plugs provided a seal before any entry is made to the body cavity. They also prevented contamination of the blood during bleeding.

Weasand clips are currently being used by most sheep processing plants to perform oesophagus sealing and cost approximately 5 cents each. With this newer technology, the clips are replaced by plugs costing a predicted 3 – 5 cents each once in production.

Research

P.PIP.0093 funded a joint industry project in which SFK trialled the use of a pneumatic mushroom head stunner on sheep and FSA investigated the complementary application of a rigid oesophagus plugging tool and plugs for the purpose of better managing ingesta contamination.

In 1997 Australian Meat Technology Pty Ltd (AMT) engaged CSIRO Food Science and Technology (now trading as Food Science Australia) to develop an internal oesophagus sealing system for sheep. CSIRO and AMT had previously developed an internal beef oesophagus sealing system (plugging) and this technology was modified and scaled down to suit sheep.

As with the beef plugging, project PRTEC.006 was intended to provide an improved method of oesophagus sealing without the risk of contamination associated with entering the body through the hide. This previous project resulted in a suitable plug design and applicator, which was successfully tested at the CSIRO Cannon Hill slaughter floor. A single cavity plastic injection die was manufactured to allow a larger number of plugs to be produced for works trials.

The tool is used to insert a plastic plug into the oesophagus via the mouth immediately after stunning and before sticking.

This does not require opening the neck, means less contamination and better efficiency.Also, by placing the plug near to the paunch entrance, it eliminates the need for rodding to separate the oesophagus from the trachea

Outcomes

While initally commercialised by SFK under the name 'SafeSeal 503', adoption was not successful and no further sales of this technology have occurred. Intellectual property protection costs were covered under project A.NTP.0002 but all protection has now lapsed.