Dynamic programming to investigate financial impacts of mastitis control decisions in milk production systems

An adaptive stochastic dynamic programming model was used to solve the opti mum replacement decision problem for the dairy cow under a range of alterna tive mastitis control procedures. The model predicted that reducing milk yi eld losses and somatic cell count penalties by using milking machine test, post-milking teat disinfection and dry cow therapy added approximately poun d4, pound 10 and pound 13 respectively to an original annuity equivalent ne t present value for the replacement heifer of pound 286. Assuming that thes e procedures also reduced involuntary culling due to mastitis by 50% added pound8.90 to the annuity. This latter figure indicated that an important pa rt of the benefit of mastitis control procedures might come from a reductio n in the culling risk of persistent clinical cases. We concluded that the s trength of the dynamic programming model in this context was that it provid ed an integrated evaluation of the various impacts of each alternative mast itis procedure in the long term, which is essential for correct economic ev aluation of mastitis.