Sibbald I R, Price K
Poult Sci. 1978 Mar;57(2):556-7. doi: 10.3382/ps.0570556.
The metabolic plus endogenous energy losses of 300 adult, White Leghorn roosters during a 24 hr period, following 24 hr of starvation, were measured. The losses ranged from 2.37 to 6.93, with a mean of 4.46, kcal/kg body weight/24 hr. Multiple regression analysis showed that only 23% of the variation in the loss/bird/24 hr was explained by differences in body weight and weight change. The measurements were made during 38 experiments spread over 3 years but there was no evidence of any relationship between the year or time of year and magnitude of the energy loss.