great lakes dairy sheep symposium - the Department of Animal ...

expensive. But it is necessary to be well organized to carry out regular CMT in suitable
conditions for large flocks of sheep.
In France, we proposed the following interpretation for the results:
CMT reaction (CMT score) Interpretation SCC equivalence
No reaction (0) Healthy or briefly infected Below 500,000 cells/ml
Small amounts of gel Small inflammation, briefly Below 800,000 cells/ml
disappearing after 10 seconds
(1)
infected
Small persistent amounts of Subclinical mastitis; long 500,000 to 1,000,000 cells/ml
gel (2)
term infection
Significant gel, deep, sticking Idem 1,000,000 to 5,000,000
to paddle (3)
cells/ml
Very deep gel, looking like Idem
Over 5,000,000 cells/ml
egg white (4)
Acute subclinical mastitis
If we take into account that CMT is a subjective test, there is a good correlation between
CMT and SCC as shown on figure 7. The distribution of CMT and SCC are in agreement.
Figure 7. Relationship between CMT and SCC for 320 udder-halves in 4 flocks (Lagriffoul 2001,
unpublished result)
SCC (* 1 000 cells/ml) cells/ml) cells/ml) cells/ml) cells/ml)
100000
10000
1000
100
10
1
0 1 2 3 4 5
CMT score
Other indirect methods like conductivity of the milk have been proposed. In general, there
are few available results in dairy sheep regarding these other indirect methods, and their
relationships with SCC are not yet as well validated as the CMT.
45