Calculation of Energy Required for the Avian Patient
MR (kcal) = K(Wkg0.75)**
Active metabolic rate is somewhat greater than that of a resting bird. For simplicity we will use the value 1.5.
Active MR (kcal) = 1.5 X MR (kcal)***
An adjustment factor for growth, trauma and disease as expressed as multiple of MR. 1
Energy requirement (kcal) = Adjustment factor X Active MR (kcal)
Volume of feeding formula (mL) = Energy requirement (kcal) ¸ caloric density of the feeding formula (kcal/mL)
* Modified from Quesenbery KE, Mauldin G, Hillyer E. Nutritional support of the Avian Patient Proc Assoc Avian Vet, Seattle, 1989, pp. 11-19.
** Resting or maintenance metabolic rate (MR), W is the animals body weight in kg, K is a theoretical constant (for calculation of MR in kcals). Passerine birds K = 129 Nonpasserine birds K = 78. 0.75 is the slope of the metabolic regression line that has been shown to correlate size and MR.
*** The difference between resting (inactive) and active birds has been reported to be 1.24 to 1.23 2 to 1.1 to 1.4.
1. Whittow GC: Regulation of body temperature, in Sturkie PD (ed): Avian Physiology (ed 4). New York, NY, Springer-Verlag, 1986, pp. 222-246.
2. Knut Schmidt-Nielsen, Scaling: Why is animal size so important? Cambridge University Press, 1984.