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.
