Submitted on August 23, 2006
Accepted on May 8, 2007
Programming of intermediate metabolism in young lambs affected by late gestational maternal undernourishment
Sanne Munch Husted1, Mette Olaf Nielsen1*, Malin P Tygesen1, Alishir Kiani2, Dominique Blache3, and Klaus Lønne Ingvartsen4
1 Department of Basic Animal and Veterinary Sciences, University of Copenhagen, Faculty of Life Sciences, Copenhagen, Denmark
2 Department of Basic Animal and Veterinary Sciences, University of Copenhage, Faculty of Life Sciences, Denmark
3 Animal Science, Faculty of Agriculture, The University of Western Australia, Nedland, Western Australia, Australia
4 Department of Animal Health, Welfare & Nutrition, University of Aarhus, Faculty of Agricultural Sciences, Tjele, Denmark
* To whom correspondence should be addressed. E-mail: mon{at}kvl.dk.
Effects of moderate maternal undernourishment during late gestation on the intermediary metabolism and maturational changes in young lambs were investigated. 20 twin-bearing sheep, bred to two different rams, were randomly allocated the last 6 weeks of gestation to either a NORM diet (barley, protein supplement and silage ad libitum ~15 MJ ME/d) or a LOW diet (50% of ME intake in NORM, offered exclusively as silage ~7 MJ ME/d). Postpartum, ewes were fed to requirement. After weaning, lambs were fed concentrate and hay ad libitum. At 10 and 19 weeks of age, lambs were subjected to an intravenous glucose tolerance test (IGTT), followed by 24 hours fasting. Heat energy was determined in respiration chamber at 9 or 20 weeks of age. LOW lambs had a lower birth weight and continued to be lighter throughout the experiment. Glucose tolerance did not differ between groups. However, 19 week old LOW lambs secreted less insulin during IGTT, released more NEFA and tended to have lower leptin during fasting than NORM. Surprisingly, several metabolite and hormone responses during IGTT and fasting were greatly influenced by paternal heritage. In conclusion, when lambs entered adolescence (19 weeks) programming effects of late prenatal malnutrition on the glucose-insulin homeostasis and metabolism became manifest: LOW lambs had less insulin secretory capacity, but this was apparently compensated by increased target tissue sensitivity for insulin, and adipose lipolytic capacity increased during fasting. Thereby glucose may be spared through increased lipid oxidation, but overall energetic efficiency is apparently deteriorated rather than improved.
