Identifying ecchymosis (blood splash) associated factors
International Colloquium on Paratuberculosis
The Deer Industry Company Report
Venison Prices
Deer newsletter goes online

Other issues of this newsletter

 

Identification of factors associated with 
ecchymosis (blood splash) in deer

From final report of  RIRDC Project UWS-12A

Investigators: Dr Robert Mulley and Mr David Falepau

Following the development of an ecchymosis grading chart in 1996 by Tuckwell and Hubbard under RIRDC
Project DAS-43A, this project was established to:

i.  identify factors associated with the occurrence of ecchymosis (blood splash); and
ii. determine slaughter systems that can minimize the prevalence of this serious meat quality defect.

The project was undertaken by Mr David Falepau under the direction of Dr Rob Mulley at the University of Western Sydney.

During the study, data was collected from 1804 deer, 1310 slaughtered at commercial abattoirs and 494 experimentally.

The study covered five types of slaughter system, three used exclusively for fallow, one for red deer and fallow and one for red and rusa deer. Characteristics of each system are described.

The incidence of ecchymosis varied significantly between the different types of abattoir. For example, of 963 fallow deer slaughtered at abattoirs of types A, B and D as defined in the report, 23% had ecchymosis equal to or greater than Grade 1 on the grading chart and 8.2% had ecchymosis greater than or equal to Grade 2 in the muscles of the round, which is indicative of ecchymosis in the loins and/or other hindleg primals. Conversely, there was no ecchymosis in 50 fallow slaughtered at a type E abattoir. Of 94 red deer slaughtered at a type D abattoir, only one had ecchymosis. The researchers concluded that ecchymosis in venison could be reduced, but only if changes specific for each type of slaughter system were adopted.

Although red deer did not appear to exhibit ecchymosis as often as fallow, this is probably because all red deer are stunned using penetrating or non-penetrating captive bolts rather than electrical stunning. In abattoirs where the time interval between electrical stunning and the initiation of exsanguination was less than 5 seconds, thoracic stick exsanguination significantly reduced the incidence of ecchymosis in comparison to the alternative method of making a gash across the neck.

In abattoirs which took 5 to 10 seconds after captive bolt stunning to initiate exsanguination, the incidence of ecchymosis was low. In abattoirs where the minimum interval possible between stunning and initiation of exsanguination was approximately 15 seconds, electrical stunning reduced the amount of ecchymosis in deer by both thoracic stick or gash methods of exsanguination, in comparison to captive bolt stunning.

Reducing the interval between stunning and initiation of exsanguination from 25 seconds to less than 10 seconds significantly reduced the amount of ecchymosis, regardless of stunning method employed (p<0.008). To avoid electrically stunned deer regaining consciousness, exsanguination must be initiated within 20 seconds of stunning, a requirement that proved difficult with deer in some abattoirs.

Reducing the interval between stunning and initiation of exsanguination from 25 seconds to less than 10 seconds significantly reduced the amount of ecchymosis, regardless of the stunning method employed (p<0.008).

As it is a requirement for the Halal slaughter of deer destined for Muslim markets, head-only electrical stunning was examined in detail. Fallow deer should be stunned using a minimum of 150 volts at 50 Hz for 1 to 3 seconds.

Where a lower voltage was used in some abattoirs (70 to 100 volts), manual restraint of the deer was necessary after stunning, to facilitate exsanguination. The researchers suggested that the down-regulation of voltage by Muslim slaughtermen should be discouraged as the interval to cessation of heartbeat (mean of 114 seconds after stunning) was not affected by voltage, whereas consciousness was affected.

The rate of blood loss achieved by the different exsanguination methods was shown to be the critical factor in development of ecchymosis. The rate of blood loss was significantly greater for the thoracic stick method of exsanguination than for the neck gash method, regardless of the stunning method used.

Where electrical stunning was used, best results were achieved with the thoracic stick method initiated within 5 seconds of stunning.  With this system, however, a delay in initiation of exsanguination will increase the incidence of ecchymosis.

Restricting the movement of the hindlegs during the seizure produced by stunning may reduce ecchymosis in hindleg muscles, but this would require specialised restraint devices.

Castrates were 10 times more likely to have ecchymosis than entire bucks, and does 4 times more likely. The reason for these sex differences was not determined, but did not appear to be related to circulating testosterone levels or the levels of other steroid hormones.

Dissection of 8 fallow deer carcasses indicated ecchymosis affected 29% of hindquarter muscles but only 0.05% of forequarter muscles. The presence of ecchymosis in the diaphragm, abdominal muscles, lungs or heart was not a reliable indicator of the presence of ecchymosis in the hindquarter muscles.

Denvering (denuding) the muscles tended to remove most ecchymosis in venison. Ecchymosis had no effect on shelf-life.

The report on this project provides practical advice to venison processors on how to go about avoiding or at least greatly reducing ecchymosis in the range of slaughter systems they are likely to encounter in Australian abattoirs, critical information for improving the quality and uniformity of Australian venison.

Copies of the 206 page report from this project are available from RIRDC by telephoning (02) 62724539.
 

International Colloquium on Paratuberculosis

From final report of RIRDC Travel Grant DEN-99

Principal Investigator: Dr Laurence Denholm

As a member of the RIRDC Deer Industry Research and Development Advisory Committtee, Dr Denholm has represented the deer industry on the National Johne’s Disease Industry Liaison Committee and its predecessor committees since 1996.

These committees have been planning national programs for control of Johne’s disease (JD) in Australia. As part of this role, Dr Denholm maintains a “watching brief” for the deer industry on international scientific developments in JD (which is known as paratuberculosis in many countries) and he reports periodically to meetings of the Deer Industry Association of Australia, most recently in Melbourne on 27th March 1999.

The International Association for Paratuberculosis holds a colloquium every three years at which the results of recent JD research and of progress in JD control programs are presented and discussed by scientists and veterinarians from all over the world. Previous colloquia were held in Iowa, Paris, Florida, Cambridge and Wisconsin.

The Sixth International Colloquium on Paratuberculosis was held in Melbourne in February this year and RIRDC supported Dr Denholm’s attendance. His report is presented in part below.

 “The 6th International Colloquium on Paratuberculosis in Melbourne was attended by 260 scientists from 26 countries. Although the majority of papers reported research on JD in sheep and cattle, many of these will have future relevance for the Australian deer industry in the context of proposed national JD control programs.

Significant developments reported at the Melbourne meeting included:

1. There is increasing interest in the control of Johne’s disease all around the world. Control programs in dairy cattle have been in place for many years in the U.S.A., the Netherlands, France and Australia, with mixed results. Successful control programs for JD in small ruminants (sheep and goats) have been in place in Iceland and Norway for many years, with Spain and several other Southern European countries now also progressing towards control programs for JD in sheep and goats. JD is spreading rapidly in Europe at present due to trade liberalisation in the E.C. and was reported for the first time in farmed red deer in Belgium last year in a herd in which there was a history of diarrhoea in the previous year in deer imported from the U.K.

2. Improving diagnostic methods for JD was one major theme of the conference. It is now clear that it is no longer appropriate to make a diagnosis of JD in a herd or flock (with resulting quarantine action), solely on the basis of culture and isolation of a mycobacteria with the particular DNA sequence called IS900, in the absence of signs of the disease in animals from which the bacteria was isolated. Several research groups reported that IS900 is not 100% specific for Mycobacterium avium subspecies paratuberculosis, the cause of JD. IS900 is also found in other bacteria, including other M. avium subspecies which can be widespread in the environment and picked up from the environment by grazing animals without any effect. With all of the regulatory consequences flowing from a diagnosis of JD, this is a particularly important issue for deer farmers as detection of an IS900 positive mycobacteria in deer might be used to diagnose JD in the absence of any signs of the disease in deer in this country, when we really know little about other bacteria in deer that may carry IS900. IS900 positive mycobacteria have been isolated from animals in Western Australia where JD is not even thought to exist. Research in NSW has suggested that another DNA sequence called IS1311 may be useful to detect differences between sheep and cattle strains of M. ptb, and may also be useful for distinguishing M. ptb from other mycobacteria with IS900.

3. There are many different strains of M. ptb around the world and the patterns of host susceptibility of these strains vary greatly. In other words, different bacterial strains, as identified by the RFLP technique of DNA fingerprinting, cause disease in different farm and wild animal species. Two major RFLP pattern groups have been identified to date, one most often isolated from sheep and the other most often from cattle. Examples of both groups have been isolated from deer and goats. However, these boundaries of host susceptibility are not absolute. Some “cattle strains” have been isolated from sheep, for example, and a “sheep strain” has been isolated from cattle with JD in Australia. Some strains are very widely distributed around the world, others have only been detected in one place. For example, local red deer in Czechoslovakia have strains A-C10 and B-C1 whereas imported Scottish red deer have strain B-C16.  In one discrete location, strain B-C1 appears to have spread to red deer and roe deer from a Charolais heifer imported from Hungary which subsequently escaoed into the wild and later died from JD due to B-C1. Sorting out the different strains and their significance as agents of disease in different species of farm livestock is becoming an increasingly difficult but increasingly important task. Czech scientists have started on this work, using 740 isolates from 11 animal species in 23 countries. So far, 23 types have been identified based on RFLP fingerprinting of their DNA, 6 of which have been found in Australia and New Zealand. The susceptibility of deer species to these 6 strains is not yet clear, but overseas 17 RFLP types have been isolated from cattle, 9 from sheep, 5 from goats, 3 from wild ruminants (mainly deer) and 4 from Crohn’s patients.

4. Taken together, these findings suggest that JD should not be diagnosed in any Australian deer herd in the absence of definitive signs of the disease in at least some animals in that herd, at least until there are DNA markers that are proven to be specific for mycobacteria with the ability to cause disease in farm livestock. This is particularly true as it is known that these mycobacteria can be isolated from the faeces of animals that are not actually infected, which raises the possibility that the mycobacteria isolated from animals without any signs of disease may simply be environmental strains (saprophytes) passing through their intestinal tracts. The possibility of bacteria passively passing through the intestinal tract must be considered, particularly where animals have been recently transported. Many bacteria from the environment can be detected in faeces, particularly when extremely sensitive tests such as the polymerase chain reaction test are used, without necessarily indicating that the animal is infected with them.

5. A number of laboratories around the world have now reported evidence of M. ptb in humans with Crohn’s disease. In all cases the mycobacteria concerned have had the DNA fingerprint pattern associated with cattle strains of M. ptb.

6. Vaccination, although effective at reducing the prevalence of disease in infected herds and flocks, does not prevent infection or the shedding of mycobacteria. Vaccination therefore does not prevent the spread of JD between infected and uninfected herds or flocks, and may actually facilitate spread by tending to mask the presence of the disease in infected flocks and herds. Nonetheless, regional control of JD by compulsory vaccination of all sheep and goats in infected regions, combined with hygiene measures, appears to have been successful in eradicating JD from most of the flocks in whole regions of some European countries.

In summary, JD is continuing to emerge as a significant animal health issue on the international stage. The scope and depth of JD research is continuing to grow, as is JD control activity. Interest in deer as a susceptible farm species and as a possible reservoir of infection in the wild is also increasing. The next colloquium in Spain in 2002 will probably produce more data on the susceptibility of different deer species to particular M. ptb strains in the field and which strains deer are most likely to transmit to or contract from other farm animals.
L J Denholm, March 1999

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The Deer Industry Company Report

Interest in the industry QA program continues to grow with 5 people from Queensland and 3 from Victoria nominating to undertake training required to become facilitators.

We hope to train the new Queensland facilitators by the end of April and new Victorian facilitators some time later. There are now 88 deer farmers and 13 deer transporters who have registered with the Deer Industry QA Board. Two more farmers are now included on the farmers who have achieved Level 3 Accreditation and these two are listed in the Deer Farming Magazine.

It is important to reiterate that farmers and transporters should be aware of the EU requirements related to the cleanliness of vehicles used to move deer that will be processed to for EU markets.  Information on cleaning requirements and associated declarations required by AQIS to allow venison to be exported to the EU can be obtained from the Board.

Registration of the industry QA marks is likely to take longer than anticipated but the process has begun.

Processor information for December 1998 to February 1999 shows that in excess of 150 tonnes of venison was processed.  Available data indicates that average venison prices continued to fall from November to February (from an average of $2.47/kg to $2.04/kg HCW less the levy, delivered to an abattoir).  The fall in overall HCW price has been more dramatic for red deer (from $2.58 in November to $1.97 in February) than for fallow deer (from $2.26 in November to $2.11 in February).

The average quality of deer carcasses available to processors for purchase (assessed by average HCW) appears to have peaked in December. During January and February the percentage of carcasses in the lower weight ranges increased slightly for both fallow and red deer.

The Deer Industry Company has now edited and reproduced 5 venison promotional brochures and produced a QA brochure, industry brochure and a velvet antler promotion brochure. The price of these brochures is yet to be determined, but is likely to be the cost of printing the brochures at best. The company has purchased a reference data base on which it is recording research papers about deer.
 
 

Venison Prices ($A/kg HCW)

FALLOW					RUSA DEER					RED
Weight Category	DEC 98	JAN 99	FEB 99	Weight Category	DEC 98	JAN 99	FEB 99	Weight Category	DEC 98	JAN 99	FEB 99
less than 20	x	x	x	less than 20	xx	xx	xx	less than 30	x	x	xx
20 to 22.9	$1.40	$1.69	$2.00	20 to 24.9	x	x	x	30 to 34.9	$1.20	$1.20	x
23 to 25.9	$2.02	$2.13	$2.12	25 to 29.9	x	x	x	35 to 39.9	$1.40	$1.40	x
26 to 28.9	$2.11	$2.28	$2.03	30 to 34.9	xx	x	x	40 to 44.9	$1.60	$1.80	$1.55
29 to 31.9	$2.40	$2.33	$2.49	35 to 39.9	xx	x	x	45 to 49.9	$2.04	$2.01	$1.84
32 and over	$2.36	$2.38	$2.55	40 to 44.9	x	x	x	50 to 54.9	$2.18	$2.15	$2.08
Maximum	$2.4057	$2.3840	$2.55	45 to 49.9	x	$2.43	x	55 to 59.9	$2.2266	$2.216	$2.20
Minimum	$1.10	$1.10	$1.79	50 to 54.9	x	$2.49	x	60 to 64.9	$2.74	$2.31	$2.30
Average	$2.16	$2.23	$2.11	55 to 59.9	x	x	x	65 to 69.9	$2.42	$2.41	$2.42
x	x	x	x	60 and over	x	x	x	70 to 74.9	$2.9367	$2.307	$1.82
x	xx	x	x	Maximum	x	$2.49	x	75 to 79.9	$2.6017	$2.341637	$1.82
x	x	x	x	Minimum	x	$2.43	x	80 to 84.9	$2.60	$2.37	$1.82
x	x	x	x	Average	x	$2.47	x	85 to 89.9	$2.60	$2.17	$1.82
x	x	x	x	x	x	xx	x	90 to 94.9	$2.60-17	$2.25	$1.82
x	x	x	x	x	x	xx	x	95 to 99.9		$1.82	$1.82
x	x	x	x	x	x	xxx	x	100 and over		$1.62	$1.62
x	x	x	x	x	x	xx	x	Maximum	$2.9380	$2.41	$2.42
x	x	x	x	x	x	xx	x	Minimum	$1.20	$1.20	$1.55
x	x	x	x	x	x	xx	x	Average	$2.33	$2.15	$1.97

 

Graph 1 below demonstrates the change in average prices for all venison sold by the cooperating processors and the average price of venison for Red (and hybrid), Fallow and Rusa deer. Graph 2 shows the variation in volume of venison processed by the processors providing data to the Deer Industry Company.

 

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Deer Products R&D Newsletter goes online

RIRDC has recently added the Deer Products R&D Newsletter to its Internet Web Page. At the moment, only the text and tables from the February and April newsletters are available online, but photographs and graphs from future editions will be available.

The RIRDC web page contains a lot of information on deer, particularly information relating to the Deer Research Program. Numerous RIRDC documents are available for downloading free of charge, including the new Deer Farming Manuals edited by Chris Tuckwell.

You can download a copy of the deer industry’s 5 year R&D Strategic Plan, the document that sets priorities for R&D funding decisions by the Deer R&D Advisory Committee and RIRDC. There are also many reports from past R&D research projects.

Over time it is likely that more and more publications will be available in this form. Lists of projects in progress and projects completed are also provided on the RIRDC site.

To use the RIRDC web page you will need to have an internet browser (such as Internet Explorer of Netscape Navigator) installed on your computer, and a dial-in connection to an internet service provider (ISP). In more remote rural areas, service is available through a special Telstra rural connection.

Some of the documents on the RIRDC site may be in PDF format and you will need to have Adobe Acrobat Reader installed on your computer to read these. This is widely available free of charge online on the Internet. Other documents on the RIRDC website including the deer farming manuals are in Microsoft Word format.

The Deer Industry Association of Australia has its own Website at http://www.diaa.org.au/diaa.htm

A number of interesting overseas sites relating to deer are available as “links” from the DIAA site.

Last updated: 14 April 1999
Copyright © RIRDC
http://www.rirdc.gov.au/pub/deer/april99.htm