Day 019 - 27 Jul 94 - Page 36
1 would say, at a low level. The most common cause, I would
say at the moment, would be probably ascites. Can I
2 recommend you address these questions to Dr. Pattison, who
keeps a continuous monitor of these mortalities for his
3 company, since he was the supervising veterinarian at that
company for a number years?
4
Q. Is it right that ascites used to be associated with high
5 altitude but it is now common throughout the broiler
industry?
6 A. It is still commonly associated with high altitude.
It is common throughout all the broiler industry in some
7 countries; in other countries, it has only just been
discovered. For instance, in Turkey they do not accept
8 broilers(?), a non-infectious form of broiler ascites.
They are only just beginning to realise that that could
9 exist. They have not identified it as yet. It is usually
associated with pasteurella, broiler ascites, so it varies
10 between countries.
11 Q. What is the cause of it?
A. There are two causes. You can get an infectious cause
12 where you have a microbe leading to the condition. The
ones I think we see more commonly in this country would be
13 non-infectious in cause. It is difficult to say what the
physiological cause is, but it is either that there is a
14 cardiac insufficiency, something wrong with the heart
itself, or there is something wrong with the lungs.
15
Now, where you have poor ventilation in the shed, you will
16 compromise any predisposition which the bird may have due
to either the cardiac or lung imperfection. Whether it is
17 due to intensive genetic selection has not been
demonstrated one way or another, but there are differences
18 between jungle fowl and broilers in the architecture of
their lungs and their capacity to absorb oxygen. There is
19 one school of thought which suggests that there could be,
as a result of intensive selection, predisposition to
20 broiler ascites.
21 Q. Compounded with the atmosphere of the sheds?
A. This is correct.
22
Q. OK, and other reasons why they might die would be from
23 dehydration and starvation, is that right? Going back to
the general point.
24 A. Yes, I would not like to put that in the category of
important in terms of numbers. If depends a lot on the
25 husbandry standard you see.
26 Q. It is only in -- on the last page of that study that we
were just referring to on page 329 where it is talking
27 about -- well, the first full paragraph: "The results
from all three studies probably underestimate the scale of
28 leg weakness because of culls and mortality. All the
assessed birds had been subject to inspection and some
29 culling, as required by law. The stockmen would have
destroyed birds which they considered to have been in pain
30 or unduly distressed. In addition, some of the birds with
a potential gait score of 4 and 5 had probably died of
