Science, or rather advancements in science, allow for new or revised tools to aid in selection and management of beef cattle. It's not hard to think of examples; artificial insemination protocol and the accompanying products (CIDRs, MGA, etc.), implants and feed additives, EPDs, economic selection indexes, genomic tools, and yes, crossbreeding strategies.
Cow sense is the ability to use science to improve the profitability of the respective beef centric enterprise. To adopt and correctly use science requires not only knowledge of the particular tool, but also detailed knowledge of the production environment and marketing goals. A recent webinar presentation to the Nebraska Ranch Practicum titled "Genetic Considerations for the Cowherd" discusses a systems approach to application of these tools. (NOTE: Webinar length - 51:57; link opens in new window)
If we focus on genetic tools and strategies, there are a few main ones that come to mind: Crossbreeding, EPDs, selection indexes, and DNA technology.
Crossbreeding, I would argue, makes economic sense for every commercial producer. However, the breeds utilized and the structure of the mating system will vary not only by region but also by individual herds. The identification of environmental constraints and marketing goals dictates the breeds that go into a crossing system. Understanding these factors allows a producer to take full advantage of the science of heterosis.
Expected Progeny Differences have been available to beef cattle producers for decades and are the fundamental backbone of genetic improvement. However, correct utilization of them requires cow sense, or knowledge of environmental constraints and production goals.
Most seedstock producers know the frustration of having advised clientele relative to bull choice only to see said client leave the sale with the exact opposite of what they really needed. There are a few good examples of this misuse of science, and thus poor cow sense.
Research has shown that cows with the genetic propensity to milk heavily require more nutrients year round, not just when they are milking. The National Research Council (NRC) data shows that a cow who produces 25 lbs. of milk at peak lactation requires 10% more feed energy than a cow producing 15 lbs. of milk at peak lactation.
To see a 10% difference in feed energy with regards to mature weight it would require moving from a 1,000 lb. cow to a 1,200 lb. cow, or a change of 200 lbs. of body weight. We know that selection for increased yearling weights has led to larger mature cows that are more expensive to maintain.