F. W.
PRIESTLEY
AND
D.
ARTIOLI
259
September 1944, the three remaining sheds
ontained 100, 100 and 97 animals; the initial
umbers of infected animals were 27, 13 and 17
espectively as judged by a single milk examination.
the last shed the 17 infected animals were moved
one end; they were milked and attended by two
walas, one incharge of 13 infected animals and
he other incharge of the remaining four infected
ogether with nine clean animals. In the first two
heds no movement of animals took place, and they
ere in fact regarded as controls. In view of the fact
hat vaccination of animals in the other three sheds
ad no effect, these animals may also be regarded as
ontrols. In other words, in September 1944,
here was one shed with infected animals at one
nd and five sheds with infected animals distributed
hroughout the length of the buildings. The
rrangements on this farm were not very satis-
actory and cooperation was only half-hearted.
No milk examinations were carried out on animals
ntering the herd, hence infection had every chance
i f being introduced.
Four months later all animals were again examined
ad the results assessed. Of the 221 originally non-
fected control animals, 39. or 17.6 per cent had
come infected; of the 32 originally non-infected
nimals in the partially eradicated shed, five or
5.6 per cent had become infected. The difference
12.0 per cent is clearly not significant.
It seems from this small experiment that in-
complete methods of eradication cannot be expected
to cope successfully with the spread of mastitis.
Complete eradication
Farm 3 contained 11 sheds of milking buffaloes.
In October 1944, when a complete examination
of the whole herd was carried out, the original
distribution of animals was as shown in Table VIII.
Thus shed 1 had 57 animals of which nine were
infected, shed 2 had 57 animals of which five were
infected and so on. On this farm the management
was very much more cooperative and experimental
conditions were more favourable.
A day or so after the first test it was decided to
eradicate all infected and doubtful animals from
sheds 3, 4, 5 and 8 and replace them with negative
animals from other sheds. These four sheds were
selected because they were in a position on the farm
where drainage and passage of milkers was away
from and not through them. The actual transfer
was carried out as follows: from shed 3, four doubtful
and seven infected animals were removed to shed 10
and replaced by 11 negative animals from shed 10;
from shed 4, one doubtful and five infected animals
were removed to shed 10 and replaced by six negative
animals from this shed; from shed 5, seven doubtful
and five positive animals were removed to shed 11
and replaced by 12 negative animals from shed 11;
and from shed 8, three doubtful and nine infected
animals were removed to shed 11 and replaced by
12 negative animals from this shed. The distribu-
tion after this move is shown in Table VIII.
TABLE VIII
Effect of eradication on the distribution of mastitis in buffaloes
Shed No.
1
2
6
7
9
10
11
3
4
5
8
Original distribution
Number
of
animals
57
57
51
54
56
56
57
58
59
54
56
Positive
9 (15.8 per cent)
5 (8.8 per cent)
11 (21.6 per cent)
11 (20.4 per cent)
7 (12.5 per cent)
11 (19.6 per cent)
10 (17.5 per cent)
7 (12.1 per cent)
5 (9.3 per cent)
5 (9.3 per cent)
9 (16.1 per cent)
Distribution after
first test in October
1944
Number
of
animals
57
57
51
54
56
55
57
58
59
55
56
Positive
9 (15.8 per cent)
5 (8.8 per cent)
11 (21.6 per cent)
11 (20.4 per cent)
7 (12.5 per cent)
23 (41.8 per cent)
24 (42.1 per cent)
..
..
..
..
Distribution in January 1945
Number
of
animals
55
47
54
53
55
51
49
40
46
56
43
Positive
16 (29.1 per cent)
7 (15.6 per cent)
11 (20.4 per cent)
15 (28.3 per cent)
18 (32.7 per cent)
31 (60.8 per cent)
24 (49.0 per cent)
6 (15.0 per cent)
7 (15.2 per cent)
4 (7.1 per cent)
8 (18.6 per cent)
—
Control
sheds
Eradication
sheds