Day 019 - 27 Jul 94 - Page 31

     
     1        flock; so small birds' leg weakness, large birds' leg
              weakness, it could be a load bearing phenomenon on the
     2        joints which, for instance, could cause angulation of the
              joints which is one of the causes of impaired gait.  So,
     3        larger birds, that is one example of how large birds and
              leg weakness can be associated.
     4
         Q.   Part of the problem is that -- I think you touched on this
     5        yesterday -- birds are bred for their weight rather than
              picking the type of bird that might have stronger legs?
     6        A.  Yes.  In the breeding programme there is great
              emphasis on growth rate in the selection criteria.
     7
         Q.   Right.  That is the main emphasis, is it?
     8        A.  That is correct.
 
     9   Q.   Do you know whether leg strength comes into it at all when
              it is being considered?
    10        A.  I can only speak for one breeding company whom we have
              had a link with and gone through their breeding criteria,
         selection criteria, and in the case of that company they
              have eight characteristics which they are selecting for or
    12        against as is appropriate with a view to improving leg
              weakness.  So they do use some criteria.
    13
              We feel we have done this experiment which I referred to
    14        yesterday with a view to seeing whether there can be more
              effective criteria.
    15
         Q.   There was one breed of chicken that did not have any
    16        problems, is there not, one set of chickens?
              A.  Yes.  I think I know which paper you are referring to.
    17
         Q.   Yes?
    18        A.  This is a random selected line of chicken.
 
    19   Q.   Yes.
              A.  In which there has been no selection pressure over the
    20        past 10 years, I believe, and their walking ability was
              perfect.
    21
         Q.   Right.  So leg weaknesses are not something that is
    22        inevitable in chickens?
              A.  Inevitable to what, sorry?
    23
         MR. JUSTICE BELL:  It is not a general chicken characteristic?
    24        A.  Oh, no.
 
    25   MS. STEEL:   If you try to breed chickens that are far more
              heavy, you are more likely to get this problem? 
    26        A.  Yes, if you do not correct it.  One of the conclusions 
              from our study could be that you can select for heavier 
    27        weight and also select against leg weakness at the same
              time and have some control over the expression of leg
    28        weakness.
 
    29   Q.   Right.  Would that actually eliminate leg weakness?
              A.  Unlikely.
    30
         Q.   The birds assessed in your study, in the Kestin study at