The economic-advantage of longevity in the dairy-cow

An adaptive stochastic dynamic programming model is described which solves the optimum replacement decision problem for the dairy cow under physical and financial assumptions currently typical for the UK. By expressing the expected net present value of the replacement heifer as an annuity equivalent under various assumptions with and without enforced (involuntary) culling an estimate of the value of longevity was obtained and an assessment made of its sensitivity to key assumptions. Increased longevity added about £20 per extra lactation per year on to the investment potential of the replacement dairy heifer under the assumptions made. This figure is sensitive to replacement cost, but could be used to provide economic values for longevity as part of an economic breeding objective for dairy cattle in the UK.