ECONOMIC OPTIMAL LACTATION PERIOD UNDER VARYING LEVELS OF MILK PERFORMANCE ON THE BASIS OF A MODEL CALCULATION

The aim of this paper was to look at the influence of lactation period on profitability in milk production under different levels of milk pe rformance. A model was set up using seven different caving intervals b etween 327 and 451 days open. After subtracting 60 days of dry period that leads to 267, 288, 303, 330, 351, 372 and 333 days in milk. Profi t was calculated for three different levels of milk production, respec tively 5000, 7000 and 9000 kg of milk per 305 days of standard lactati on. As a result shorter days of lactation (267 respectively 288 days) lead to a decline in profitability. Assuming optima conditions of mana gement and fertility an extension of days in milk clearly improved the economic efficiency of the enterprise. The increase in profit was mor e significant under a higher compared to a lower production level. An extension of days in lactation due to bad management or problems in fe rtility lead to a strong decrease in profitability.