Tissue integrity impacts of application of 160–200 kJ of 915 MHz microwave energy, using the DTS: Diathermic Syncope® system, to the forehead of cattle, and alignment with the requirements of religious slaughter markets

TL;DR

This study examines the effects of microwave energy on cattle brains and skin, finding minimal damage that may align with religious slaughter requirements.

Contribution

The study provides empirical evidence that microwave stunning causes minimal tissue damage, potentially reconciling animal welfare with religious slaughter standards.

Findings

Application of microwave energy caused no visible brain tissue damage and minor histological changes possibly due to processing.

Forehead temperature remained near ambient initially, then peaked after energy application ceased.

Post-mortem heat retention likely caused depilation and skin changes observed on carcasses.

Abstract

•Application of 160–180 kJ energy to the forehead resulted in no visible damage to brain tissue.•Minor histological changes in brain could be associated with processing artefact.•Forehead temperature remained close to ambient for the first 8 – 12 s of energy application (max duration of application 12 s), then rose steadily to a peak, and began to fall when energy application ceased.•Depilation and skin changes noted on carcases after bleed-out are likely due to retained heat and are likely to occur post-mortem.•Minimal impacts on brain and skin tissue may comply with religious slaughter requirements.

Application of 160–180 kJ energy to the forehead resulted in no visible damage to brain tissue.

Minor histological changes in brain could be associated with processing artefact.

Forehead temperature remained close to ambient for the first 8 – 12 s of energy application (max duration of application 12 s), then rose steadily to a peak, and began to fall when energy application ceased.

Depilation and skin changes noted on carcases after bleed-out are likely due to retained heat and are likely to occur post-mortem.

Minimal impacts on brain and skin tissue may comply with religious slaughter requirements.

Although society desires good animal welfare at slaughter, there is a tension between some religious requirements and modern commercial stunning methods. The DTS (Diathermic Syncope®) system has been designed with a vision of relieving that tension, rendering the animal unconscious within 0–5 s, by applying 160–200 kJ of 915 MHz electromagnetic energy to the forehead, while limiting damage or changes to the tissues. To investigate this latter aspect, surface temperature at the point of application was measured using fiber optic sensors in 12 animals; application point hide skin of 3 animals was examined histologically; 7 brains were inspected and palpated shortly after energy application; and four brains were examined histologically. There were no gross morphological changes to the brain, and limited evidence of changes on histological examination. Temperatures at the point of application remained close to the ambient (29.0–36.5 °C) prior to and for the first 8–12 s of energy application (max duration of application 12 s), then rose steadily to a peak, and began to fall when energy application ceased. Maximum recorded temperature was 54.27 (± 6.56) °C, which occurred after energy application had ceased. Although small numbers of animals were included in this study, they and the process used were representative of the normal operation through the commercial abattoir. Depilation and effects on forehead skin noted on carcases after bleed-out are likely to be exacerbated by post-mortem change. These findings may comply with religious slaughter requirements.

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