The California Net Energy System: Theory and Application

THEORETICALLY, the California Net Energy System (CNES) contains some inconsistencies in maintenance energy requirement (NEm). The adequacy of the specific gravity technique to determine energy content in lean animals is questionable and deserves additional experimentation. Furthermore, the associative effects of feeds and effects of changing intakes are not directly considered. The use of the CNES in feedlots is an improvement over other systems used. Our data suggest that where environments are severe and stressful, the accuracy of the system is decreased. In cold environments, accuracy can be improved by appropriate correction factors applied to NEm requirements. Environmental impact on performance may differ in the various regions of the country. Therefore, any corrections to the system would have to be modified accordingly. If no stress exists, or is accounted for, the system can be applied with considerable precision to finishing feedlot cattle. The precision for growing feeder cattle is less. The reasons for this are obscure, but may be related to the accuracy of determining energy retention in lean cattle.