To estimate the dietary ME concentration, often feed tags list the Total Digestible Nutrient (TDN) concentration. Likewise, most commercial feed laboratories estimate the TDN concentration based on various analyses, such as for crude protein and fiber fractions.
The approach used to develop predictions of voluntary DM intake by goats was based on an assumption of constant
overall efficiency of utilization of ME. Therefore, ME requirements from other studies of this
project were employed, along with assumptions of efficiencies
of ME utilization. In accordance, inputs necessary to predict
intake entail factors influencing the partitioning of energy
for use in various physiological functions, including production
level. Although this calculator will predict feed intake with negative ADG, the majority of observations in the database used to develop the prediction equations had positive ADG or values near or slightly less than zero. Hence, caution should be employed when predicting intake with substantial body weight loss. It is also important to note that input of an unreasonably
high level of production given the characteristics of the
animal and nature of the diet will result in a comparable
unlikely estimate of feed intake.
Data on which this calculator is based were from
goats in pens or stalls and not in late gestation or experiencing
appreciable compensatory growth or effects of acclimatization.
Correspondingly, adjustments of the maintenance ME requirements
available in other calculators are not employed here. Therefore,
caution should be exercised if using this calculator to determine
if an estimate of feed intake based on a ME requirement calculator
with the maintenance requirement being substantially affected
by adjustments is likely or not. However, adjustments can be used with the Option B Calculator ""Feed Intake with Adjustments of Maintenance Energy Requirements - Mature Goats"
Our example would require a voluntary DM intake of a 40-kg meat goat with 0 ADG and consuming a diet with a ME concentration of 9 MJ/kg DM and 9 and 12% CP are 0.76 and 0.82 kg/day, respectively.