Day 020 - 28 Jul 94 - Page 20


     
     1        our experience, for instance, we have found birds have not
              been stunned when we have subjected them to 75 milliamps
     2        per bird using a 50 herz sinosoidal AC.  They have shown
              immediate escape behaviour on taking them out of the water
     3        bath.  Yes, there is a risk.  That is with a brief
              application of current.
     4
         Q.   What do you mean by "brief"?
     5        A.  It was less than three seconds.  It was two to three
              seconds, I think, if my memory serves me correctly.
     6
         Q.   Are you of the view that currents of less than 75
     7        milliamps should never be used?
              A.  When using a 50 herz sinosoidal AC, I am.
     8
         Q.   Do you say that does not bear any relation to the type of
     9        stunning machine?
              A.  I think the answer at the moment is that I do not
    10        know.  We are doing experiments on other waveforms at
              Bristol at the moment.  I cannot give you a definitive
    11        answer what the minimum recommendation would be for a 500
              herz DC at the moment, but we soon will be able to.
    12
         Q.   Right.  Is it not likely that a DC current is less likely
    13        to induce cardiac arrest?
              A.  It depends on the frequency.  I think frequency is
    14        more important than whether it is a direct current or an
              automating current, but a high frequency, such as 500
    15        herz, is very unlikely to induce a cardiac arrest, even at
              high current levels.
    16
         Q.   So certainly at low current levels it is not going to?
    17        A.  That is correct.
 
    18   Q.   Is it not more likely that some birds are not going to be
              stunned at all?
    19        A.  The lower the current you give a bird, the less likely
              it is to stun, yes.
    20
         Q.   This is a paper I wanted to go through.  There are a
    21        couple of points in it.  I have actually got four copies
              of this one.  (Handed).
    22
         MR. JUSTICE BELL:  I think this is a paper of yours?
    23        A.  Yes.
 
    24   Q.   I will put it at the back of your orange bundle in due
              course.  Yes.
    25
         MS. STEEL:   On page 217 of that, in the middle of the section 
    26        on "Recovery experiment", it says:  "The average time to 
              return of tension in the neck muscles tended to increase 
    27        with increasing stunning current.  Of greater importance,
              however, was the increase in the lower limit of this
    28        measure with increasing current.  When 45 and 60 mA were
              used some birds failed to lose neck tension and based on
    29        this criterion they were not stunned."  Then when a higher
              current was used neck tension was lost for a minimum of 52
    30        seconds.  Was this the study you were referring to a
              little while ago?

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