HOW MUCH IS A GENETICALLY SUPERIOR RAM WORTH

The economic value of a genetic difference between rams was estimated for stud and commercial tiers in the Australian Merino industry. Disco unted returns were predicted using the method of Hill (1974). Results were generated for breeding schemes considering natural mating (Scheme A), artificial insemination (Scheme B), the use of home-bred sires at daughter stud level (Scheme C) and the use of culled stud ewes in row er tiers (Scheme D). The effects of discount rate and ram flock life w ere assessed. The value of one extra unit of genetic merit in three tr aits (Clean Fleece Weight, Fibre Diameter and WOOLPLAN index score) wa s found for commercial, daughter and parent tiers. One extra kilogram of clean fleece weight (CFW) was worth around $817 for a commercial le ver ram (all Schemes) and up to $390000 for a parent level ram in Sche me B. The same improvement was worth $4 per semen dose used at commerc ial level, and up to $3977 at parent stud level (Scheme B). Increasing the discount rate devalued later returns, reducing the number of disc ounted expressions. Increasing ram flock life increased ram value but reduced semen value. The results are discussed for current industry pr actice and values obtained previously for commercial rams. The economi c value of multiple ovulation and embryo transfer is considered.