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An Evaluation of Central Nervous System Cross-Contamination Due to Carcass Splitting in Commercial Beef-Packing Plants

Authors: Bowling, M.B.1; Yemm, R.S.1; Belk, K.E.1; Sofos, J.N.1; Smith, G.C.1; Scanga, J.A.1

Source: Journal of Food Protection®, Volume 71, Number 1, January 2008 , pp. 83-92(10)

Publisher: International Association for Food Protection


Abstract:

Four experiments were conducted in commercial beef-packing facilities The objectives of these experiments were to: (i) determine and validate a carcass sampling technique and location to determine if central nervous system (CNS) cross-contamination exists/occurs; (ii) determine if residual CNS tissue contamination remains on splitting saws after sanitation procedures; (iii) determine the prevalence of CNS cross-contamination in commercial slaughter facilities; (iv) determine whether washing treatments reduce or eliminate CNS tissue presence in carcass-splitting saws; (v) determine the effectiveness of commercial spray-washing systems in removing CNS tissue from beef carcasses; and (vi) compare residual CNS tissue levels on the blade and in the housings of the Jarvis Buster IX and Buster IV carcass-splitting saws. CNS tissue remained, albeit at very low levels, in the housings and on the blades of carcass-splitting saws after carcass splitting and operational sanitation. Additionally, after splitting carcasses, CNS tissue remaining in the splitting saw housings and on saw blades was found to cross-contaminate subsequent carcasses during splitting. Most splitting saw operational sanitation procedures reduced the amount of CNS tissue remaining in the splitting saw housings and on splitting saw blades, but no treatment eliminated CNS tissue from either to levels below the detection limit of the assay (6 ng/100 cm2). Washing in carcass spray-washing cabinets at three of the five commercial beef-packing facilities reduced, but did not eliminate, presence of CNS tissue in the aitch bone area of carcasses. Carcass spray washing in cabinets at three of the five facilities reduced (P < 0.05) the concentration of CNS tissue in the fourth thoracic vertebra area. While extremely low concentrations of CNS tissue remained in the splitting saw housings, on the splitting saw blades, and on carcasses, it is unknown whether these levels would pose a human food safety risk because the exact amount of bovine spongiform encephalopathy-infected spinal cord capable of transmitting the disease to humans is dependent on the infectivity titer, which is not readily known.


http://www.ingentaconnect.com/content/iafp/jfp/2008/00000071/00000001/art00013#aff_1


Brilliant, 2008 and we are still pondering this in the USA, what will they think of next......


VETERINARSKI ARHIV 75 (1), 83-100, 2005* Contact address:prof. Dr. vet. med. Spyridon Basilios Ramantanis, Department of Food Technology, Technological Educational Institution (T.E.I.) of Athens, Agiou Spyridonos Str., 122 10 Egaleo, Athens, Greece, Phone: +30 210 5385 506; Fax: +30 210 5314 874; E-mail: [email protected] ISSN 0372-5480Printed in Croatia

Preventive measure against possible BSE-hazard: Irreversible electrical cattle stunning - a review

http://www.vef.hr/vetarhiv/papers/2005-75-1-11.pdf


course tam et al figured this out a long time ago ;


-------- Original Message --------
Subject: Docket #03-025IF -- Docket #03-038IF -- Docket #01-033DF -- SUBMISSIONS -- USDA ISSUES NEW REGULATIONS TO ADDRESS BSE
Date: Thu, 08 Jan 2004 15:33:20 -0600
From: "Terry S. Singeltary Sr."
To: [email protected]
CC: [email protected]


Greetings FDA,

I would kindly like to make a submission to Federal Docket Docket
#03-025IF -- Docket #03-038IF and
Docket #01-033DF -- TSS SUBMISSIONS -- USDA ISSUES NEW REGULATIONS
TO ADDRESS BSE

Garland et al (1996). “Brain emboli in the lungs of cattle after stunning,” Lancet 348(9027), p. 610.).


end...tss

see full text ;

https://web01.aphis.usda.gov/regpublic.nsf/0/eff9eff1f7c5cf2b87256ecf000df08d?OpenDocument


even further back in history ;


BSE INQUIRY PAGE 29 ...

AS far as splitting of the head goes and the use of band saws, I would have thought that that is not being done at the moment, is that not right ?


http://www.bseinquiry.gov.uk/files/tr/tab56.pdf


Carcass-splitting and removal of spinal cord

2.116 Spinal cord was made an SBO under the 1989 Regulations. The legislation did not expressly regulate carcass-splitting and removal of the spinal cord. However, some investigations were made into ways to reduce contamination of the carcass by the spinal cord. These led to attempts to create a double-bladed saw which could cut around the spinal column on both sides. Dr Gracey said in oral evidence:

What they have been trying to do with the . . . carcass-splitting saws is to have a double-bladed effort which not just removes the spinal cord but takes out the whole column. 30

http://www.bseinquiry.gov.uk/files/tr/tab56.pdf

2.117 One of the driving forces behind the attempts to perfect new methods of spinal cord removal was commercial pressure from the supermarkets, which were major buyers of fresh meat. Mr Colin Maclean, Director-General of the MLC, said that:

. . . some of the supermarkets became concerned about the spray caused by sagittal splitting of carcasses with saws that clearly sprayed spinal cord fragments on to the spinal column particularly, but perhaps also on to other parts of the carcass. And therefore for a presentational reason, because at that stage we did not believe that that was any major threat we started the work. Well, we did not believe it was a threat at all, I think is the honest answer at that stage.

But to deal with the perceived concern, we started work on sucking devices to try to suck the spinal cord out of the column without sagittally cutting the carcass. We spent a lot of time in our own workshops because we have a cutting plant and cutting rooms in our own offices where we can do that sort of work. And we spent about a year and a half trying to achieve removal of the spinal cord in a way that could meet the line speeds of the abattoir, obviously. It is not just a matter of getting it out, it has to meet the commercial needs of the industry.

We did not succeed at that time. Therefore we stopped that work not because the problem had gone away but because the supermarkets had retreated from their area of concern as more knowledge had been disseminated in the industry the concern associated with the sawing of carcasses had receded throughout the industry. It remained so until probably 1994/95, when the challenge returned again. Despite our failure with that sucking device we kept the equipment and so on and so forth but retreated from the research. 31

http://www.bseinquiry.gov.uk/files/tr/tab59.pdf

http://www.bseinquiry.gov.uk/files/ws/s147b.pdf


2.118 Other theoretical ways of removing the spinal cord completely which were mooted in the early 1990s included blowing out the cord from the intact carcass and cutting with lasers. These were found not to be commercially viable at the time. 32



2.119 It was already common practice in 1989 to remove the spinal cord from the vertebral column of adult cattle so as to improve the appearance of the meat, but after the introduction of the 1989 SBO Regulations, the spinal cord was dropped into a bin for staining. 33 Problems with removing it intact (see above, and paragraphs 2.48ff) are also considered in vol. 6: Human Health, 1989-96.



snip...


xii) Carcass-splitting and removal of spinal cord

2.48 Following evisceration, the hind legs of the carcass were anchored as far apart as possible. The carcass was then split vertically in half, using a band saw, reciprocating saw or circular saw (although meat cleavers were sometimes used in smaller slaughterhouses), so that the carcass could be further inspected and reduced to a manageable size. A power saw took about 15-25 seconds to complete the splitting. The cut was made through the mid-line of the spinal column although some veering from the mid-line would inevitably take place. Generally, the spinal cord was then removed, to improve the appearance of the meat, by drawing a thumb, knife or blunt hook down the length of the spinal canal. Most spinal cord was thrown into a receptacle to be sent for rendering, or washed to drains. A small amount would have remained stuck to the spinal column and been passed on to mechanically recovered meat manufacture or for rendering. 29

2.49 Mr Raymond Bradley, the CVL's BSE research coordinator, described the process of carcass-splitting in oral evidence:

. . . in all bovine adults carcasses are split, and there are a number of ways of doing it. Mostly they use, and today I think the majority, if not all of them, are reciprocating or band saws of some description. In . . . some . . . there were circular saws just like you would use for sawing through a large log of wood. And these were water-cooled. In order to stop the spray, the carcasses, at the point of splitting, were enclosed in what we might loosely call like a shower cabinet but it was made of polythene and it was thick polythene or that kind of material and it was incomplete in stopping the spray, and it was absolutely obvious to me, because I was getting sprayed that there was water, at any rate, coming out from this, and any carcass or person in the vicinity could potentially be exposed to this. 30
2.50 Mr John Baker of the MLC said in oral evidence:

The reason we [removed the spinal cord] in those days was when you were transporting bone-in beef it made the beef arrive cleaner at the other end and it always presented the meat better; it is a presentation in as much as what we did it for in the early days. We obviously did not take it out as clean as we [do] today now. 31
2.51 Conflicting evidence was received by the Inquiry as to whether or not the spinal cord could easily be removed intact. Mr Christopher Clark, from the Meat Hygiene Service (MHS), described the process in oral evidence:

[First] of all legislation requires carcasses to be split. Following splitting and final trimming of the carcass, ie neck trim, spinal cord, thymus and surplus fat, then the spinal processes would be washed to remove bone dust. It is best practice to wash in a downward direction with emphasis on water volume as opposed to pressure. There is a requirement to control this waste water. It is usual for the station where the splitting takes place to be screened to contribute to the control of that waste water, and also for health and safety reasons.
The spinal cord, in my opinion, remains intact after sawing. Many saws have a continuous flow; they are high speed saws. The water from that saw is then directed by means of a pipe into a receptacle or directly into a trapped drain with fine mesh. I think most plants would exercise these controls. As I have said I do not think there is maceration of the spinal cord. 32
2.52 Other evidence received indicated that removing the entire spinal cord was not so easy. For example:

When you split a carcass, if you get it right down the mid-line, it is easy to remove the spinal cord but if you go slightly off centre, a piece of the spinal cord is trapped in the canal and is difficult to remove, and it is then quite a business to have to take the carcass back and either split open the canal with an axe or take it back to the saw, and this slows down the line and slows down production and so on. So if you are enforcing your order rigorously you have to make sure that that is done, whereas I think the feedback that was coming through at that time was that, you know, if that happens then nobody would have been particularly bothered about it. That side of beef would have gone through with that little piece of spinal cord still left in the vertebral column. 33
There were certainly cases where it was difficult [to remove the spinal cord intact]. It relied on the quality of the saw, the expertise of the operator of the saw and very often it would come off in two or three pieces or . . . the meat inspector had to take additional bits of spinal cord out prior to stamping. 34
During the carcass-splitting a mechanical splitting saw travels down the spinal axis of the suspended carcass. Whilst the spinal cord may be 'pushed aside' by the blade of the saw, thus remaining generally complete, this is not usually the case. The spinal cord is usually severed, on occasions along its length, spreading cord tissue along the whole cut surface of the split carcass. The result is that both the carcass, the saw blade and the environment are contaminated, again potentially with the infective agent of BSE. As with the removal of the brain . . . washing of the cut surfaces merely acts to spread the contamination. 35
. . . in smaller abattoirs, where either because the equipment was less well maintained or was less modern and because perhaps operatives in some cases were less skilled . . . it was possible for the saw to deviate off the mid-line, so that it would not expose the actual foramen through the spinal column, the hole where the spinal cord runs. So if the saw deviated there would be a section where the spinal cord would be not visible at that point. So, of course, removal at that point was not done. 36
2.53 From this evidence, it appears that there were practical problems with both approaches to carcass-splitting: an accurate mid-line cut allowed clean removal of the spinal cord but could spread cord tissue along the saw and carcass; an off-centre cut would mean less contamination but left pieces of cord trapped in the canal.

2.54 Even when the entire spinal cord was removed intact, other nervous tissue was still left in the carcass. This included dorsal root ganglia, which were 'swellings on the dorsal roots of spinal nerves [containing] the cell bodies of sensory neurons'. 37

2.55 The carcasses of young calves were not split. 38 Under the Fresh Meat Export (Hygiene and Inspection) Regulations 1981, export slaughterhouses were only required to split carcasses of bovines over 3 months old. 39 Later, this requirement was changed so that only carcasses of bovines over 6 months old had to be split. 40

2.56 This was the third post-mortem inspection point, where the dressed carcass was checked for such things as cleanliness and odour (see below for more information).


http://www.bseinquiry.gov.uk/report/volume13/chapterf.htm#245024



NOW, 2008, and we are still discussing options in the USA ???


WHAT were the options back then, and what were they thinking $$$


Gerald Wells: Report of the Visit to USA, April-May 1989

snip...

The general opinion of those present was that BSE, as an
overt disease phenomenon, _could exist in the USA, but if it did,
it was very rare. The need for improved and specific surveillance
methods to detect it as recognised...

snip...

It is clear that USDA have little information and _no_ regulatory
responsibility for rendering plants in the US...

snip...

3. Prof. A. Robertson gave a brief account of BSE. The US approach
was to accord it a _very low profile indeed_. Dr. A Thiermann showed
the picture in the ''Independent'' with cattle being incinerated and thought
this was a fanatical incident to be _avoided_ in the US _at all costs_...

snip...

http://www.bseinquiry.gov.uk/files/mb/m11b/tab01.pdf



OBSERVATIONS AND RESULTS

A New Incidence of TME. In April of 1985, a mink rancher in Stetsonville, Wisconsin
reported that many of his mink were "acting funny", and some had died. At this time, we
visited the farm and found that approximately 10% of all adult mink were showing
typical signs of TME: insidious onset characterized by subtle behavioral changes, loss of
normal habits of cleanliness, deposition of droppings throughout the pen rather than in a
single area, hyperexcitability, difficulty in chewing and swallowing, and tails arched over
their _backs like squirrels. These signs were followed by progressive deterioration of
neurologic function beginning with locomoior incoordination, long periods of somnolence
in which the affected mink would stand motionless with its head in the corner of the
cage, complete debilitation, and death. Over the next 8-10 weeks, approximately 40% of
all the adult mink on the farm died from TME.
Since previous incidences of TME were associated with common or shared feeding
practices, we obtained a careful history of feed ingredients used over the past 12-18
months. The rancher was a "dead stock" feeder using mostly (>95%) downer or dead dairy
cattle and a few horses. Sheep had never been fed.

http://www.bseinquiry.gov.uk/files/mb/m09/tab05.pdf




Thursday, January 3, 2008

ANIMAL HEALTH REPORT 2006 (BSE h-BASE EVENT IN ALABAMA, Scrapie, and CWD)


http://animalhealthreport2006.blogspot.com/



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