A recent symposium at the National Western Stock Show looked at the optimal beef cow. The conclusion was that the optimal cow exists, but no one knows who she is.
By its nature, "optimum" is never optimum for long when you're talking about biological animals. With the genetic tools we have available today, the optimum beef cow of 20 years ago should be a sub-par cow today.
Differing geographical locations, management practices and marketing programs can all dramatically shift the definition for what the ideal beef cow is. A farmer in Iowa retaining ownership on all his calves and selling them on a carcass-weight basis through a value-added beef grid has a totally different definition of "ideal" from a rancher in Arizona who sells all his calves at weaning.
The optimum beef cow has to be determined via a total-systems approach, where efficiency is measured not only at the ranch gate but throughout the production process. Efficiency, in and of itself, has to be separated from all the rhetoric to get to the science of it.
It's almost universally accepted, for instance, that animals with smaller frame scores equate to more efficiency from the cow side but less efficiency from the fed-animal side. However, the data would indicate there's really no difference in biological efficiency as it relates to mature size. And that -- while frame size is a moderately good indicator of mature size -- it's certainly just an indicator trait. Small isn't necessarily better.
To find the optimum beef cow, you have to have a very good understanding of the resources, economics and marketing opportunities of a given operation. Then you fine-tune mature size, milk production, growth, mating systems, etc., to that set of resources and factors.
Multi-trait and balanced-trait selection has always been the answer, but marketing and the laws of differentiation have always encouraged single-trait selection. That's why there's so much discussion about that optimum beef cow.
The odds are you won't find her in a situation where the goal is to maximize production and carcass traits. Likewise, you won't find her where somebody is trying to ignore everything past the ranch gate, either.
-- Troy Marshall