Economic optimization of dairy heifer management decisions

A farmer exercises control over the heifer rearing unit in two main areas: a nutritional plane of growth and the moment of insemination. The two manag ement controls interact with biological aspects of growth thereby influenci ng future profitability of the dairy heifer. A dynamic programming model wa s developed to optimize these decisions for individual heifers, using the h ierarchic Markov process (HMP) technique. NMP provides a method to model a wide variety of heifer calves, differing in age, season, body weight, repro ductive status and prepubertal growth level. Under Dutch conditions the opt imal rearing strategy resulted in an average calving age of 22.6 months at a calving weight of 564 kg. Faced with the scarcity of exact information on the interrelationships of rearing strategies with the productivity of the dairy replacement, the strength of this heifer model lies in the field of t he sensitivity analyses by providing valuable information regarding the cri tical components of heifer rearing. (C) 1999 Elsevier Science Ltd. All righ ts reserved.