Estimating the value of genetic gain in perennial pastures with emphasis on temperate species

Relatively little is known about the weightings that breeders consciously or subconsciously place on specific traits when selecting individual plants, or the weightings agronomists and producers use when evaluating the relative merits of alternative cultivars and their potential economic value in farm systems. This is despite the many active programs for breeding improved forage plants, and in contrast to most modern animal-breeding programs where the relative merits of novel genetics are assessed against index-based breeding objectives. There are many reasons why breeding objectives based on profit indices are not used when breeding pasture plants. The nature of pasture as an intermediate input to farm output and profit poses unique difficulties in developing breeding objectives based on profit. In this paper, we review the literature about methods to value genetic gain in perennial grasses. Various methods are canvassed for assessing the value of genetic gain for different pasture species across production systems. In the context of the complexity and cost of estimating the direct economic benefits of superior characteristics of pasture plants in farm systems via bio-economic simulation methods, we outline the use, and usefulness, of discrete choice techniques in the development of weightings for specific traits in forage plant improvement. There is a clear need to estimate the value of new pasture cultivars to producers, and although the differences between individual farms mean that one value or one 'best' cultivar is unlikely for any farm, the estimation of potential value of traits and cultivars will allow producers to make choices that are more informed.