Effect of undernutrition in foetal life on energy expenditure during gestation in ewes

Abstract

The long-term effect of early life undernutrition on late gestation energy expenditure (EE_gest) was investigated in sheep. Ewes were fed either adequate (100%) or restricted (60%) energy and protein during late foetal life as well as during last trimester of gestation later in life, resulting in three groups: Adequate-Adequate (AA, n = 5), Adequate-Restricted (AR, n = 5) and Restricted-Restricted (RR, n = 5). At two weeks pre-partum, EE_gest were calculated from respiratory gaseous exchange and nitrogen excreted in urine and further it was partitioned to energy expenditure for conceptus development (EE_conceptus) and homeorhetic adaptations in maternal metabolism (EE_homeorhetic). Late gestational energy and protein restriction reduced the EE_gest in the AR ewes (4.1 MJ · d⁻¹) but not in the RR ewes (5.2 MJ · d⁻¹) compared with the AA ewes (6.8 MJ · d⁻¹). Based on conceptus-weight, no significant difference was found in EE_homeorhetic among the groups; 172, 175 and 169 kJ/kg · d⁻¹ in AA, AR and RR ewes, respectively. However, EE_conceptus was significantly lower in AR (135 kJ/kg · d⁻¹) in comparison with AA (298 kJ/kg · d⁻¹) and RR (252 kJ/kg · d⁻¹) ewes. In conclusion, exposure nutrient restriction in early life impairs the ability of ewes to respond to nutritional restriction in terms of energy expenditure of gestation.

Keywords:

• metabolic programming
• energy metabolism
• heat production
• sheep
• pregnancy

Acknowledgements

This study was financed by the Iranian Ministry of Research, Sciences and Technology (IMRST) and by Faculty of Life Sciences, University of Copenhagen, Denmark. The authors wish to thank A. Ali, M. Stubgaard, and K. Thorhauge, for their great expertise and assistance.