Under today's difficult farming conditions, the farmer must examine every aspect of management that may improve economic efficiency. Apart from the usual areas such as feeding and the use of variable and fixed costs, there is scope in terms of improving health and fertility of the cattle in the herd. This is particularly so at the present time, as the standards of such performance are generally low. The main losses occur in animals with endometritis, lameness, mastitis, extended calving intervals and excessive involuntary culling. The cost in a 100 cow herd of carrying average rates, rather than practically attainable target rates, is around 10,000 pounds per year. By only using the direct costs of disease and by including indirect costs separately, as measured by whole herd fertility indices, double counting has been avoided.