There has been a tremendous buzz throughout the beef industry the last few years and the buzz is “efficiency”. Almost every symposium and popular press publication has at least one talk or article about efficiency.

Indexes (residual feed intake and residual average daily gain) have been developed and accepted by the Beef Improvement Federation and most breed registries. All this is with good reason. Feed input costs are usually the largest single expense for beef producers. If feed costs could be reduced or outputs per unit of feed increased, profitability would increase.  However, as we explore and find new methods to select cattle (i.e. efficiency), it appears we are heading into an arena that has more “unknowns” than “knowns”.

For example, reducing feed costs have obvious beneficial implications, but at what cost? And are the advantages truly as beneficial as we think? Do we understand the ramifications of selecting for efficiency?

Knowledge that is already available

As we search for new ways to increase efficiency and ways to make our  systems more profitable, are we forgetting about knowledge that is already available? Feed intake is an extremely important topic and when applied correctly, can have a marked impact on the finances of an operation.  But, doesn’t it make more sense to utilize the increase in efficiency that heterosis provides and select bulls for profitability rather than efficiency?

Research reported in the 1980s (Short et al.) described the order and importance of nutrient partitioning and assimilation. It was concluded that energy was not partitioned evenly nor randomly, but rather had defined biological orders of importance. Basal metabolism was the first order of importance for nutrient use, followed by requirements for growth, energy reserves (storing fat), pregnancy, resumption of estrous and reproductive processes.

The question we don’t understand is how animals with varying efficiencies partition nutrients. It seems likely that highly efficient animals for one trait must partition their use of nutrients differently from animals with lower efficiency. This may seem elementary, but it is important to remember that all consumed are to be partitioned to support important metabolic functions.