title: Partitioning of late gestation energy expenditure in ewes using indirect calorimetry and a linear regression approach.
abstract: Late gestation energy expenditure (EE(gest)) originates from energy expenditure (EE) of development of conceptus (EE(conceptus)) and EE of homeorhetic adaptation of metabolism (EE(homeorhetic)). Even though EE(gest) is relatively easy to quantify, its partitioning is problematic. In the present study metabolizable energy (ME) intake ranges for twin-bearing ewes were 220-440, 350- 700, 350-900 kJ per metabolic body weight (W0.75) at week seven, five, two pre-partum respectively. Indirect calorimetry and a linear regression approach were used to quantify EE(gest) and then partition to EE(conceptus) and EE(homeorhetic). Energy expenditure of basal metabolism of the non-gravid tissues (EE(bmng)), derived from the intercept of the linear regression equation of retained energy [kJ/W0.75] and ME intake [kJ/W(0.75)], was 298 [kJ/ W0.75]. Values of the intercepts of the regression equations at week seven, five, and two pre-partum were 311, 398, and 451 [kJ/W0.75], respectively. The difference between the intercepts for different weeks was used to calculate EE(homeorhetic). The remaining part of EE(gest) was considered to be EE(conceptus). In conclusion, the good agreement between our values of EE(conceptus) and those in the literature indicates the method's validity.
authors.affiliation: Department of Basic Animal and Veterinary Sciences, Faculty of Life Sciences, Copenhagen University, Denmark.
authors.forename: Alishir
authors.initials: A
authors.lastname: Kiani
authors.forename: André
authors.initials: A
authors.lastname: Chwalibog
authors.forename: Mette O
authors.initials: MO
authors.lastname: Nielsen
authors.forename: Anne-Helene
authors.initials: AH
authors.lastname: Tauson
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001835:Body Weight / Q000502:physiology; D002153:Calorimetry, Indirect / Q000379:methods / Q000662:veterinary*; D002149:Energy Intake / Q000502:physiology*; D004734:Energy Metabolism / Q000502:physiology*; D005260:Female; D020567:Fetal Weight / Q000502:physiology; D016014:Linear Models; D009751:Nutritional Requirements; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D012756:Sheep / Q000378:metabolism / Q000502:physiology*