In the general outline of the success, on a national scale, of the eradication of
bovine tuberculosis in France up to 1974, we have tried to find out the factors which could explain the differences, sometimes important, between French departments in the efficiency of this eradication. We have selected twenty seven parameters distinctive of each of the 74 departments having more than 50 000 bovine under the control of State Veterinary service. These parameters describe 1)
tuberculosis infection rates of animals and herds, at three periods; 2) some structural characteristics of bovine production; 3) sanitary environment (veterinary practicioners, State Veterinary service, breeders association for sanitary protection). Statistical analysis by principal components show that department
infection rate decreases as the first three factors evidenced by this analysis vary positively; they are: 1) "Sanitary Consciousness", which is defined both by the important of bovine production and by precociousness in developing prophylactic measures, these two factors being independent. 2) Specialization in bovine production, characterized by the percentage of young animals reared in the herd and by the proportion of grass produced by ley. 3) Intensity of sanitary environment. These three factors, which are interlinked to various degrees, control respectively 25%, 13% and 13% of the total variance. A complementary analysis of the data suggest that the efficiency of eradication could be improved by a better knowledge of the movement of breeding animals between the departments, and by a more careful recording, in some instances, of infected animals in slaughter hourses. When the importance of a herd increase sanitation of
tuberculosis in infected herds is less readily achieved and
brucellosis abortion rate increases. At the departement level, efficiency of eradication is not correlated to the expenses of prophylaxy. For the development of an integrated sanitary policy, taking into account such non specific factors as those exemplified in the study could help to a better control of
animal diseases, in parallel to the desirable improvement of the specific means of combatting each disease.