Abstract :
A database including 80 treatment means, based on energy balance publications, was constructed and analyzed to estimate
fasting heat production (FHP) and ME required for maintenance (MEm) of goats. Experiments entailed comparative slaughter,
respiration calorimetry or CO2 entry rate techniques. Goats were of eight breeds and five physiological states (preweaning;
growing; mature and non-lactating; early and mid-pregnancy; and lactating). Assuming that heat increment was 40% of total
heat energy, unweighted, and weighted (number of observations per treatment mean) log–log regressions (n = 74 following
removal of observations to increase explained variation) of FHP against BW resulted in FHP (kJ) = 299 × BW0.762 (R2
= 0.82) and 244 × BW0.826 (R2 = 0.75), respectively. The 0.762 and 0.826 BW scaling factors did not differ (P < 0.17) from
0.75. The slope and intercept of a regression of recovered energy (RE) against ME intake (MEI) for preweaning goats differed
(P < 0.01) from those for other physiological states. A linear regression analysis of RE on MEI (both kJ/kg BW0.75) was
conducted with the remaining 71 observations, after removing two observations with SD greater than 2.5 residual SD. The
resultant equation was: RE = −298.0 (SE = 22.38) + (0.691 (SE = 0.028) × MEI) [n = 69; R2 = 0.90]. These estimates
of FHP and efficiency of ME use yielded an estimate of MEm of 431 kJ/kg BW0.75. In summary, FHP and MEm of 298 and
431 kJ/kg BW0.75, respectively, appear appropriate as general descriptors of the maintenance energy requirement of goats
consuming diets at, near or above maintenance.
© 2004 Elsevier B.V. All rights reserved.
