[Nervous syndrome in sheep on the Ivory Coast. II. Economic impact, trials and cost-benefit analysis of preventive plans]. / Le syndrome nerveux des ovins en Côte-d'Ivoire. II. Importance économique, essais et analyse coûts-bénéfices de plans de prophylaxie.

ABSTRACT

The clinical and epidemiological aspects of the ovine nervous syndrome in Côte-d'Ivoire were presented in the first part of this paper and the disease was considered to be similar to the cerebrocortical necrosis as related to vitamin B1 deficiency. The economic losses by this disease being 1,500 to 2,000 F CFA (30-40 FF) per animal and per year, it seemed to be very important to consider its prophylaxis. A programme involving a daily injection of 100 mg of thiamine chlorhydrate throughout the dry season proved to be very efficient. In addition, if excluding the cost of the injection, this programme appeared to be beneficial to the farmer. When including only the price of the product, the profit to cost ratio of the programme was 4.8 (thiamine at 400 F CFA) to 30.6 (thiamine at 66 F CFA). The other profit earning criteria, i.e. the differential actualized net value and the induced gains, showed the same positive effect of this prophylaxis programme. However, it should be emphasized that the nervous syndrome in sheep mainly remains an accident due to a poor flock management. Hence, to prevent this disease the farmer should correctly adapt the rearing methods to the intensification of the production. Nevertheless, as the accurate etiopathogenesis of the syndrome remains to be elucidated and as the daily injection of the product to all animals of the flock represents an important constraint, research should be pursued to solve a problem which seems to affect the whole region.