Defining Biological Efficiency of Beef Production
     It’s nearly impossible for U.S. beef producers to define “biological” efficiency without consideration of “economic” efficiency. According to animal scientist David R. Notter, Virginia Polytechnic Institute, the separate but significant contributions to beef production of grazed forages and harvested concentrates, and the potential substitution of one feed source for the other, dictate that economic considerations must influence the definition of biological efficiency.
     Notter says key economic factors include costs of grazed forages vs. harvested concentrates, and the complex U.S. beef marketing system. With these factors in mind, Notter defines biological efficiency as “the capacity to convert physical inputs (feed) into marketable product (beef) under prevailing production conditions.”
     Traits that support biological efficiency in the brood cow are generally different from those associated with efficient postweaning calf growth, admits Notter. Improved forage utilization and reproductive performance will enhance cow efficiency, while efficiency in the growing market animal is achieved through a balance of appetite and lean growth potential.
     However, Notter concludes that biological efficiency reflects options as much as optimums. Most biological characteristics of the cow are negotiable, depending on environment and market goals, but efficient cows are those that produce calves regularly and easily. Biological efficiency of the calf is more dependent upon the market and the association between intramuscular fat and quality.
     “Biological efficiency is the servant of economic efficiency,” states Notter, “and that master is best served by having the biological diversity to rapidly accommodate changes in markets and economic variables.”
— Troy Smith