By Nancy Lidster www.dnlfarms.com
Our purpose is to make the work of moving pigs safer and easier for handlers and to improve pig and handler welfare in the process.
This is the third in a series of articles outlining concerns with the pig handling content of Canada’s “Code of Practice for the Care and Handling of Pigs”.
BACKGROUND:
Canada’s “Code of Practice for the Care and Handling of Pigs” like many other training documents used in the pork industry, emphasizes the Flight Zone / Point of Balance model to describe pig behaviour.
The previous article outlined:
general problems associated with using the “pig’s flight zone” to explain pig behaviour
benefits from using a “handler’s bubble” approach instead of the flight zone
This article will look at the history and science of the flight zone diagram that is used in the Canada’s “Code of Practice for the Care and Handling of Pigs”. The code is available at:
http://www.nfacc.ca/pdfs/codes/pig_code_of_practice.pdf
WHAT IS “SCIENCE”?
Canada’s code is described as “science based”. What is science?
Scientific Method: Figure 1 is one of many graphics on Google depicting the Scientific Method.
Figure 1
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Figure 1 shows science as a systematic process of testing and revising theories to arrive at more accurate understanding of a given question.
Science as applied in The Code Development Process
The Code Development Process is outlines in the code’s preface. The code’s preface provides links to the Scientific Committees report and includes the following quote.
“The Codes of Practice are the result of a rigourous Code development process, taking into account the best science available for each species, compiled through an independent peer-reviewed process, along with stakeholder input.”
The process trusts that because a scientist’s published work has been reviewed by her /his scientific peers, it must be based on sound scientific methods and be accurate.
The Flight Zone in the Code
Like many other training resources, the code emphasizes use of the flight zone to move pigs.
Figure 2 is from page 58, Appendix K of the code. Its source is code Reference 43 which is noted below the diagram.
Figure 2.
Reference:
The independent peer-reviewed process brought this diagram to the pages of Canada’s code and similar diagrams to other pig handling training courses. Where did the diagram come from?
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History of the Flight zone diagram:
Figure 3 is from a paper Dr. Temple Grandin presented to the annual meeting of the Iowa VMA in January 1979. (The diagram was “Figure 7″ in her article.)
Figure 3.
Dr. Grandin’s caption clearly states that her diagram is intended to show the correct handler position for moving a single animal through a curved chute. The handler position in Figure 3, Dr. Grandin’s cow flight zone diagram, is the same as the handler position in Figure 2, the code’s pig diagram.
What happened between the original cow diagram and the code’s pig diagram?
Initial changes:
Over time the original diagram Figure 3 was modified to what is shown in Figure 4:
pig was interchanged with cow
blind spot added
point of balance labelled
the handler positions remained unchanged but with the addition that moving from position B to position A would stop movement
references to the curved chute were dropped
the diagram was presented as a prescription for all pig moving situations
Figure 4
Source: PQAPlus Version 1.2
Subsequent changes:
Collective memory failed. Many people had no idea what the lines depicting a curved chute were about. Lost or disregarded, the chute lines were often dropped from flight zone diagrams. Some of the graphics changed but elements such as handler positions and point of balance were left unchanged.
Thus Figure 3 (cow) transformed into Figure 4 (PQAPlus) and ultimately into Figure 2 (code).
Following the trail:
The transitions from Dr. Grandin’s original diagram, Figure 3 to the flight zone diagram used in Canada’s pig code, Figure 2 can be mapped through various scientific peer-reviewed documents. In essence, the peer-reviewed process and the two flight zone diagrams imply that:
a pig in the open will respond the same as a cow in a chute
the same handler position is effective in both situations
Questions:
Has anyone actually applied scientific methods to test the hypothesis that “a pig that is not confined in a chute: that is free to turn and move in any direction, will respond to a handler’s position precisely the same way as a cow that is confined in a chute and can only move forward, backward, or stop”?
Have scientific methods been applied to confirm that the single handler position shown in Figures 2,3,and 4 is the most effective and appropriate in all pig handling situations?
Summary:
Dr. Grandin’s original flight zone diagram detailed a very specific set of conditions. The specific conditions detailed in Figure 3 are not at play in the vast majority of on farm pig moving situations. Trying to impose that model where it doesn’t apply causes problems for handlers.
Details of the handler position shown in Figures 2 and 4 cause additional problems which will be addressed in our next article.
Source: DNL Farm