After feeding, fertility is the factor which has the greatest effect on the economics of dairy farming.

Maintenance of good fertility is to a large extent governed by management, and this means that the individual farmer or herdsman has a very important part to play in its control.

At 1998 UK values, agricultural economists quote a loss of up to £3.50 per cow for each day that the calving interval is extended beyond 365 days. Figures such as these, cited in abstract, often have relatively little meaning, however, and the following gives an idea of how the amount is calculated. I would urge the reader to insert current day values and local prices in order to calculate a truly accurate cost.