Day 090 - 16 Feb 95 - Page 58


     
     1        five years.  So, any changes that are made, inevitably,
     2        come through the chain fairly slowly.  So, it is very
     3        important to keep reviewing these characteristics all the
     4        time to make sure that the breeding programmes are on
     5        track.
     6
     7   MR. JUSTICE BELL:  Is there some particular respect in which you
     8        are going to suggest Sun Valley should propose improvement
     9        to the supplier?
    10
    11   MS. STEEL:  Yes.  (To the witness):  Have you made any
    12        suggestions about improving leg strength, for example?
    13        A.  Leg strength is something that we certainly discussed
    14        with them, and they have quite a -- they have made quite
    15        impressive progress over the years in reducing the
    16        incidence of genetically determined leg disorders, such as
    17        tibial dyschrondroplasia is a good example, where they have
    18        actually had an X-ray programme of their elite stock to
    19        X-ray every bird in the pedigree population to eliminate
    20        any that are carrying signs of tibial dyschrondroplasia.
    21        So, that is one example where good progress has been made.
    22
    23   Q.   Have you made any suggestions in terms of breeding for leg
    24        strength overall, as opposed to rapid weight gain, that
    25        type of thing?
    26        A.  There is always a compromise that has to be made.  In a
    27        genetic programme you are probably selecting for 20 or so
    28        different traits, and you always have to balance one
    29        against the other.  Now, it would obviously be totally
    30        ridiculous to be selecting for excessive weight gain which
    31        did not allow the animals to be able to stand up properly.
    32        So, the compromise always is to grow, to select the birds
    33        which grow the fastest, but also that maintain leg strength
    34        and other characteristics which are commercially necessary.
    35
    36   Q.   There is quite a considerable percentage of the birds at
    37        Sun Valley that do have leg weaknesses.  How do you feel
    38        that squares with what you have just said?
    39        A.  Well, the leg weakness that we see now, and I actually
    40        feel that Sun Valley have probably made more progress than
    41        others, most of the leg weakness that we see relates to
    42        infectious causes and some of it has certainly happened as
    43        a result of other infectious conditions, such as Gumboro
    44        disease, but we have also seen leg problems caused by
    45        E.coli, by staphylococcus, and we are learning how to
    46        control these infectious causes as we go.  It is a constant
    47        improvement process.
    48
    49   Q.   Those infectious causes, are they particular problems of
    50        the broiler industry? 
    51        A.  They are problems common to the industry. 
    52 
    53   Q.   You could select birds mainly on the basis of their leg
    54        strength, could you not?
    55        A.  You could, yes, you could do that.
    56
    57   Q.   And why do Sun Valley not do that?
    58        A.  Well, as I say, we do not select, we do not have the
    59        gene pool, the genetic material, to allow us to do that.
    60        That has to be done by the primary breeding company.

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