Cow Efficiency Update

No important differences have been found between breed groups and no effect of cow size on cow efficiency has been detected. These results appear to be in agreement with other published reports dealing with cow size and breed differences where (1) the annual energy intake for the cow and calf has been measured, (2) the output resulting from net energy input has been measured, and (3) the cow has been fed sufficient energy to maintain reproduction. These experiments have been conducted in environments from Texas to Canada and with a variety of methods used to determine intake level of the cows. The cow has indicated a marvelous ability to adjust her output to the energy input provided, even in one experiment where the plane of nutrition varied sufficiently to affect reproduction