Calculated energy requirements of lactating and non-lactating Hereford cows.

Abstract

Most studies conducted to determine energy requirements of mature cow for maintenance, weight gain and milk production have been with dairy cattle. As increasing emphasis is placed on economical production of beef, it is important for research workers to provide information indicating cost, in terms of total digestible nutrients (TDN),metabolizable energy (ME or net energy (NE), of maintenance, change in body weight and milk production of mature beef cows. Actual energy requirements for maintenance and production are individualistic and change from time to time within cows. A realistic measure of the mean requirements and a knowledge of the range in requirements is needed. Thus, this study was conducted to provide a portion of this information. Trials were conducted in 1967 (Trial 1) and 1968 (Trial 2). In Trial 2, source of forage was changed and slightly higher levels of TDN were used; otherwise, the procedures were the same as for Trial 1.