dts: diathermic syncope® - induction of insensibility in cattle · july 2015 *advanced microwave...

DTS: Diathermic Syncope® - induction of insensibility in cattle

AGRICULTURE FLAGSHIP

Alison Small; Joanne Hughes; David McLean*; James Ralph#

July 2015*Advanced Microwave Technologies; #Wagstaff Cranbourne Pty Ltd

Section 1: Background

2 | DTS: Diathermic Syncope. Induction of insensibility in cattle

Humane Slaughter

• Billions of cattle are slaughtered each year around the world to produce meat, a valuable source of protein in our diets.

• We are all agreed that slaughter should be carried out in the best possible manner• Humane• Rapid exsanguination, maximal blood removal• Optimized meat quality

• Modern commercial slaughter often involves stunning• Insensibility

– Humane– Increased operator safety

• Existing stunning methods are not acceptable to all markets

DTS: Diathermic Syncope. Induction of insensibility in cattle3 |

Issues related to existing stunning methods

• Mechanical stun causes trauma, and visible damage to the skull• The animal is then not whole and undamaged at the time of exsanguination

– Very important to religious markets• Reduced stunner power can reduce the visible damage to the skull, but the stun might not be effective• With effective high power stuns, the majority of animals will not recover at all.

– Those that do ‘recover’ tend only to partially recover, before brainstem oedema results in clinical death


Issues related to existing stunning methods

• Head only electrical stunning can be fully recoverable, but:• In cattle, the duration of unconsciousness is very variable, and can be very short• In cattle, electrical stunning has been associated with meat quality problems such as blood speckle and

blood splash in the carcass.


Other ways animals (or humans) fall unconscious

• General anaesthetics• Pharmaceuticals in blood stream and tissues

• Fainting (Syncope)• Loss of blood pressure• Hyperthermia (heat stress)

– Brain temperature above 43°C


DTS: Diathermic Syncope ®

• Electromagnetic energy (922 MHz)• Focused into the brain• Volumetric heating


Mode of action

• Induced Hyperthermia• Above 43° C• Below 50 ° C

• Possible electromagnetic effect

• Previous work• Rats (Guy and Chou 1982)• Chickens using TMS (Lambooij et al. 2011)• Anaesthetised Sheep (Small et al. 2013)• Anaesthetised Cattle (Rault et al. 2014)


Other applications for E-M energy

• Eye surgery therapy• Pulses of energy to the cornea to heal keratoconus (bulging)

• Hypertension• Pulses of energy to block the nerves contributing to high blood pressure

• Cosmetic surgery• Tighten skin, lipolysis

• Surgery• Removal of cancers and warts

• Magnetic Resonance Imaging

• Ranges used: 1-1000 MHz


Section 2: The pilot study

ObjectivesMaterials and Methods


• Proof of concept determination of:• Induction of insensibility• Endocrine responses• Meat quality attributes

– Post slaughter– One week post slaughter (vacuum packed) – Ten weeks post slaughter (vacuum packed)

• In cattle subjected to:• Captive bolt stun prior to exsanguination• DTS

DTS: Diathermic Syncope. Induction of insensibility in cattle

Pilot Study Objective

11 |

• 18 Aberdeen Angus cross bred heifers• 350-400 kg liveweight

• Rested in lairage 4 days• Low-stress handling

• 7 assigned to captive bolt• 11 assigned to DTS• 3 high penetrative energy

– (>290 kJ)• 4 low penetrative energy

– (<200 kJ)• 4 intermediate (200-290 kJ)


Animals

12 |

• Restrained in knocking box• Pre-stun blood sample taken• Head captured in chin-lift• Baseline EEG• Assigned stun method applied• Unconsciousness confirmed• Animal rolled out onto cradle• Post stun EEG• Exsanguinated (brachiocephalic sticking method)• Post-stun blood sample


Procedures at stunning

13 |

• Behaviour and reflexes (live)• Corneal reflex• Palpebral reflex• Pupillary response• Focusing and following• Nose prick

• Behavioural responses (video)

Carcass measurements

• pH declines and pHu• Colour at quartering• Inspection during boning• Muscle samples• M longissimus lumborum• M semitendinosus• Vacuum packed


• pH declines and pHu• Colour at quartering• Inspection during boning• Muscle samples• M longissimus lumborum• M semitendinosus• Vacuum packed• Stored 1 week and 10 week

– pH– Shear force– Drip loss– Lipid oxidation– Colour

Sample measurements• Muscles• pH• Shear force• Drip loss• Colour• Lipid oxidation

• Blood samples• ACTH• Cortisol• Catecholamines• β-endorphin



Results


Live observations at stun application

• Initial rapid blinking, followed by fixed, staring eyes• No corneal response• No blink response• No evidence of eye following hand movement

• Initial tucking in of legs, followed by extension• Slow paddling/walking movements in some animals• Then stiff extended limbs• Then convulsions begin

• Rhythmic deep breathing throughout• Heart beating throughout• Strong blood flow on exsanguination


EEG


Captive bolt conscious 2 min Post stun

DTS conscious 2 min Post DTS 4 min post DTS

EEG data


Parameter Captive Bolt DTS Significance#

Mean power (μV)

Baseline Mean ± St Dev -2.08 ± 74.9 7.33 ± 128.54 n/s

Post treatment Mean ± St Dev -1.97 ± 87.90 1.67 ± 43.49 n/s

Terminal Mean ± St Dev 15.87 ± 150.76 -0.01 ± 54.39 n/s

RMS (mV2) Baseline Mean ± St Dev 0.86 ± 0.78 1.02 ± 1.97 n/s

Post treatment Mean ± St Dev 0.77 ± 1.30 0.62 ± 0.95 n/s

Terminal Mean ± St Dev 0.29 ± 0.55 0.60 ± 0.92 n/s

Amplitude (mV)

Baseline Mean ± St Dev 4.42 ± 4.13 5.36 ± 10.80 n/s



Median Power Frequency (F50)(Hz)




95% Spectral Edge Frequency (F95) (Hz)




Indicators of insensibility

• Eye open and staring straight ahead / glazed expression• Corneal reflex absent• No spontaneous eye blinking• No vocalisation in response to stimulus• No response to painful stimulus


Carcass inspection


No evidence of ecchymoses or blood splash

pH declines and pHu

Captive bolt DTS® Difference

5.69 ± 0.05 5.68 ± 0.06 Not significant at P<0.05


pHu below 5.8 – within normal range (<5.8)

Colour at quartering


MINOLTA Captive bolt DTS Difference

L* 33.45 ± 0.50 33.71 ± 0.67 Not significant at P<0.05

a* 23.16 ± 1.39 23.74 ± 1.86 Not significant at P<0.05

b* 1.06 ± 0.44 2.71 ± 0.59 P<0.05

• Note: Very small sample size– n = 7

Stored muscles: pH


1 week Captive bolt DTS Difference

LL 5.50 ± 0.03 5.50 ± 0.04 Not significant at P<0.05

ST 5.45 ± 0.02 5.48 ± 0.02 Not significant at P<0.05

pH – within normal range




Stored muscles: Shear force





kgf - within normal ranges (3.5 to 9.96)




Stored muscles: Drip loss





% lossWithin the wide ranges cited in literature




Stored muscles: colour

• One week storage



LL L* 33.73 ± 0.82 36.05 ± 1.11 Not significant at P<0.05

a* 20.89 ± 0.69 23.22 ± 0.92 P<0.05

b* 0.77 ± 0.70 2.79 ± 0.93 P<0.05

ST L* 40.94 ± 0.78 43.32 ± 1.05 P<0.05


b* 4.12 ± 0.56 5.25 ± 0.75 Not significant at P<0.05

• Note: Very small sample size– n = 7

Stored muscles: colour

• Ten week storage



LL L* 35.14 ± 0.67 36.06 ± 0.90 Not significant at P<0.05



ST L* 41.04 ± 0.89 42.75 ± 1.19 Not significant at P<0.05



Endocrinology


Analysis Captive Bolt

DTS Difference

Change in Cortisol between pre-and post-treatment samples (nmol/L)

MeanSt Dev

99.21±17.19

117.19±23.07

Not significant at P<0.05

Change in ACTH between pre-and post-treatment samples (ng/mL)

Mean* 0.141 0.051 Not significant at P<0.05

Change in β-endorphin between pre- and post-treatment samples (ng/mL)

MeanSt Dev

-0.25±0.56

-0.51±0.76

Not significant at P<0.05

Change in Adrenaline between pre- and post-treatment samples (ng/mL)

Mean* -146.16 -17.28 Not significant at P<0.05

*backtransformed data


Conclusions


Conclusions 1

• DTS induced insensibility. There was evidence of EEG suppression for 3-4 minutes post energy application;

• DTS animals remained unresponsive to stimuli, with no evidence of the eye beginning to focus and follow movement for 3-4 minutes post energy application;

• DTS animals maintained rhythmic breathing and a strong heart beat throughout the period of insensibility;

• Two animals showed evidence of return to consciousness, including the righting reflex;


Conclusions 2

• DTS produces comparable endocrine responses in cattle to those stunned using captive bolt.

• DTS produces comparable post slaughter meat quality in beef carcases to those stunned using captive bolt.

• Based on the current study, there are no reasons to halt further development and commercialization of DTS as a stunning method for cattle


Future work

• Optimize energy delivery parameters• Current study utilized a delivered energy range of 100 - 300 kJ• 100 kJ – shorter duration of stun• 300 kJ – likely to be non-recoverable

• Investigate consistency of recovery• Important to religious markets


Section 5: Acknowledgements


Acknowledgements


Wagstaff Garfield, VIC

The technical team

CSIRO Food Science Engineering Group (1980’s and onwards)

Co-authors:David McLeanJames Ralph

Alison SmallResearch Scientistt +61 2 6776 1435e [email protected]

AGRICULTURE FLAGSHIP

Thank you

dts: diathermic syncope® - induction of insensibility in cattle · july 2015 *advanced microwave...

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