Abstract
Fasting heat production was measured 1 and 31 days after lactation ceased in postabsorptive dairy cows varying in daily rate of milk yield just prior to fasting. Daily fasting heat production was higher at 1 than at 31 days, particularly in higher-producing cows. It averaged 100 .+-. 3 kcal/kg body weight.cntdot.75 31 days after lactation ceased. [The use of the net energy system to estimate cattle feed requirements is discussed.].